Outcomes of pulmonary rehabilitation in older adults with chronic obstructive pulmonary disease: a systematic review

Abstract

Background

Outcome heterogeneity in pulmonary rehabilitation (PR) for older adults with chronic obstructive pulmonary disease (COPD) limits evidence synthesis and hampers clinical standardization. This review aimed to identify and categorize the outcome indicators, measurement tools, and assessment time points in PR studies for older COPD patients, to inform a future core outcome set (COS).

Methods

This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses–COnsensus-based Standards for the selection of health Measurement INstruments (PRISMA-COSMIN) 2024 guideline. The study protocol was prospectively registered with PROSPERO (CRD420250652844). Eight databases were searched from inception to February 2025. Study characteristics, outcome indicators, measurement tools, and time points were extracted. Outcomes were categorized into domains based on the Core Outcome Measures in Effectiveness Trials (COMET) taxonomy and analyzed descriptively.

Results

A total of 95 studies (n = 204,626) were included, reporting 590 outcome indicators consolidated into 148 unique types across six domains: Physiological/Clinical (64.92%), Functional Status (18.14%), Life Impact, Psychosocial, Adverse Events, and Mortality. Geriatric-specific outcomes such as balance and physical activity were identified but inconsistently reported; for instance, balance function was assessed in only 3 studies (3.16%), frailty in 2 studies (2.11%), and physical activity ability in 6 studies (6.32%). Reporting of adverse events (e.g., falls) and mortality was notably limited. The overall evidence quality ranged from moderate to high.

Conclusion

Outcome assessment in PR for older adults with COPD is multidimensional and requires age-specific sensitivity. This review provides a critical evidence base for clinical practice and future research. Future research should develop a COS integrating geriatric-specific indicators to enhance consistency and personalization of care. The findings directly support clinicians and researchers in selecting appropriate, comprehensive outcome measures that reflect the priorities of older adults with COPD, thereby improving the impact of rehabilitation programs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-026-07810-2.

Introduction

The global prevalence of chronic obstructive pulmonary disease (COPD) is approximately 10.3%, and it rises sharply with age [1]. A systematic review on the global prevalence of COPD revealed prevalence rates of 15.84% and 24.03% in the 60–69 and ≥ 70 age groups, respectively [2]. The World Health Organization has estimated that annual deaths from COPD and related diseases could reach 5.4 million by 2060 [3]. With population aging and continued exposure to risk factors, the burden of COPD is expected to worsen further in the coming decades [4]. Additionally, the Global Burden of Disease 2021 report emphasizes that COPD is not only a leading cause of disability-adjusted life years among the older adults but also a major driver of healthcare expenditure [5].

Pulmonary rehabilitation (PR) is recognized as a primary non-pharmacological treatment for COPD and one of the most cost-effective approaches, forming a core component of COPD management [6, 7]. Notably, the delivery of PR has evolved beyond traditional inpatient and outpatient settings to include home-based and remote (tele-rehabilitation) models [8]. While institution-based programs enable direct multidisciplinary supervision and access to laboratory-based physiological assessments, home-based and remote models—characterized by self-monitored or virtually-supervised exercise—offer enhanced accessibility for older adults with mobility or transportation barriers [9], albeit with outcome measurement inherently constrained to field-based functional tests and patient-reported outcome measure (PROMs). However, the significant heterogeneity in outcome measures across existing PR studies considerably limits the comparability and evidence synthesis among different trials. Outcome indicators in PR are diverse, encompassing dyspnea, exercise tolerance, psychological status (such as anxiety), quality of life, among others, with variations also existing in measurement tools and assessment time points [10]. Outcome measures reflect the responses of subjects to interventions and serve as the most critical element for inferring the efficacy of these interventions [11]. Appropriate outcome indicators can enhance the consistency and feasibility of randomized controlled trials (RCTs) and reduce reporting bias; conversely, the use of inappropriate or selectively reported outcomes may cast doubt on the validity and purpose of RCT findings [12].

In recent years, Souto-Miranda et al. established the first core outcome set (COS) for PR in COPD through a systematic review and a modified Delphi study [13, 14], which includes nine key outcomes such as dyspnea, fatigue, exercise capacity, and quality of life, providing an important foundation for standardizing outcome assessment in PR research. However, this COS and systematic review were not developed specifically for, nor does it adequately address, the unique needs and clinical priorities of the older adults population. And it also did not it specify the precise measurement instruments or optimal time points for assessing these outcomes. Older adults with COPD often exhibit distinct response trajectories and outcome characteristics in PR interventions due to declines in physiological function, a higher burden of comorbidities, and greater variability in treatment responses [15, 16]. Furthermore, the interplay between COPD and common geriatric syndromes—such as sarcopenia, frailty, and cognitive decline—can exacerbate functional impairment and necessitate outcome measures that extend beyond traditional pulmonary function tests [17]. Consequently, outcome domains critical for geriatric care—such as balance, activities of daily living (ADL), and polypharmacy-related issues—are not represented, limiting the COS’s applicability and effectiveness in guiding practice for this dominant patient subgroup.

Therefore, this study aims to conduct a systematic review of existing literature to identify commonly used outcome measures, measurement instruments, and assessment time points in PR for older adults with COPD. By mapping the current outcome landscape and identifying both prevalent measures and geriatric-relevant gaps, this review serves as the essential first step toward developing a tailored COS for older COPD patients. The findings are expected to provide evidence to support the optimization of rehabilitation protocols, standardize clinical practice, and promote individualized rehabilitation strategies for this population. Ultimately, this work is designed to enhance the consistency, comparability, and clinical utility of PR research and practice, ensuring that outcome assessment aligns with the goals and challenges of caring for an aging COPD population.

Methods

This study has been registered with PROSPERO (Registration number: CRD420250652844). The Preferred Reporting Items for Systematic Reviews and Meta-Analyses–COnsensus-based Standards for the selection of health Measurement INstruments (PRISMA-COSMIN) 2024 guideline was utilized to guide the reporting of this study [18].

Literature search

The databases searched included: PubMed, Cochrane Library, Embase, Web of Science, China National Knowledge Infrastructure, Wan Fang Data, Chinese Science and Technology Periodical (VIP) Databases, Chinese BioMedical Literature Database. No grey literature sources were included. The literature search employed a combined strategy integrating subject headings and free-text terms. Additionally, the reference lists of the included studies were traced back to supplement the retrieval of relevant literature. The detailed search strings for each database in Appendix A. The search cutoff date for the literature was February 2025.

Eligibility criteria

Inclusion criteria: (a) Population: Studies were included only if they explicitly restricted enrolment to patients with COPD aged ≥ 60 years old. Mixed-age studies (i.e., those including any participants < 60 years) were excluded, irrespective of mean age or subgroup data availability, to maintain a purely geriatric sample and minimize population heterogeneity. (b) Intervention: The intervention measure for the experimental group is PR, which includes institutional, home-based, and remote rehabilitation. (c) Comparison: No specific limitations on the control interventions. (d) Outcome: All extractable outcome indicators from the included studies. (e) Study types: Cohort studies, randomized controlled trials, experimental studies, and quasi-experimental studies. (f) Both Chinese and English literature.

Exclusion criteria: (a) The intervention group receiving additional intervention measures (not part of PR); (b) Studies with vague reporting on the characteristics of the study subjects and the intervention methods; (c) Conference abstracts, preprints, reports that are overly simplistic, or those for which the full text cannot be obtained, etc.; (d) Duplicately published literature.

Data extraction and analysis

Literature organization and classification were conducted using Rayyan [19]. Two researchers (X.W. and Y.D.) independently carried out literature screening, summarizing, and categorizing according to the inclusion and exclusion criteria, and then performed cross-checking. A data extraction form was developed. The extracted content from literature studies mainly included: author(s), year of publication, country, study type, sample size, age, intervention measures, outcome indicators, measurement tools, and measurement time points. Two researchers independently classified outcome indicators with inherently similar meanings into agreed-upon outcome terms. In case of disagreements, a third author was consulted for discussion to reach a consensus on the result. Subsequently, another author (J.X.) compared the consolidated list of results. Finally, the outcome measures were systematically classified into a set of outcome domains. This process was guided by the standardized taxonomy of the Core Outcome Measures in Effectiveness Trials (COMET) Initiative [20] and informed by the classification method for core outcome sets in progressive pulmonary fibrosis, as described by Delameillieure et al. [21]. The research team reviewed, discussed, and revised the consolidated outcomes and the domain selection results.

Quality evaluation

Two researchers (C.Z. and G.L.) independently evaluated the literature studies that met the inclusion and exclusion criteria and cross-checked the results to determine their internal validity and risk of bias. In cases of disagreement, resolutions were reached through discussion or consultation with a third party. For RCTs, Version 2 of the Cochrane risk-of-bias tool (RoB 2) was employed [22]. For quasi-experimental studies and experimental studies, the Risk Of Bias In Non-randomized Studies - of Interventions (ROBINS-I) tool was used [23]. For cohort studies, the Newcastle-Ottawa Scale (NOS) was utilized, with quality graded as follows: high quality (score 7–9), moderate quality (score 4–6), and low quality (score 1–3) [24].

Results

Selection results

A preliminary search yielded 7,907 articles, comprising 640 Chinese articles and 7,267 English articles. After deduplication, full-text reading, and other screening steps, a final total of 95 clinical studies were included [25–119]. The literature screening process is illustrated in Fig. 1.

Fig. 1.

Flowchart of literature screening process

Basic characteristics of the study

A total of 95 studies were included, involving 204,626 patients. Of the included studies, 57 were RCTs, 29 were quasi-experimental studies, 9 were cohort studies, 1 was experimental study. Publication dates ranged from 2001 to 2025. Most PR programs were implemented in home settings (30) or during hospitalization combined with home settings (22). All 81 studies reported the duration of the intervention, with the shortest being 2 months and the longest being 1 year. A summary of the included studies and study characteristics can be found in Table 1.

Table 1.

Main characteristics of included studies (n = 95)

Studies	N	Age	Measures		ID	Outcome indicators and their measurement tools	Measurement time point	Setting of PR
			IG/EG	CG/N-EG
Hu (2001), China, RCT [25]	58	IG:69.40±5.70 CG:68.10±4.70	Aerobic and respiratory training	Conventional respiratory medicine symptomatic treatment	6m	PF: Using a PF testing equipment to measure FEV1, FEV1/FVC, FVC QOL: QOL Rating Scale	Baseline, 6m	Inpatient and Home-based
Ip et al. (2004), China, Cohort study [26]	130	EG:81.50±7.00 N-EG:79.40±6.00	PR	Usual care	NR	Readmission rate: Frequency record	28days, 100days	Inpatient and Home-based
Katsura et al. (2004), Japan, quasi-experiment [27]	59	IG:69.04±0.40 CG:78.6±0.60	Inpatient PR	No	2w	QOL: QOL Rating Scale Dyspnea: OCD Exercise tolerance: 6MWT	Baseline, 3m, 6m, 12m	Inpatient
Kongsgaard et al. (2004), Denmark, RCT [28]	18	IG:71.00±1.30 CG:73.00±1.80	Heavy progressive resistance training	Non-supervised daily breathing exercises	12w	PF: Using a spirometry to measure FEV1 CSA of quadriceps: MRI Isometric and isokinetic knee extension peak: Kin-Com dynamometer Isometric trunk extension：Leg press Technogym Leg extension power: Nottingham Power Rig Gait speed: 30 m track	Baseline, 3m	Outpatient
Zhang et al. (2004), China, quasi-experiment [29]	34	61-88	Clinical drug therapy and respiratory rehabilitation therapy		6m	PF: Using a PF testing equipment to measure FEV1, FEV1/FVC, FEV1%pred, FVC, MVV, DLCO Cough, Sputum production, Shortness of breath: Frequency record ADL: ADL scale ADL: ADL scale Degree of respiratory distress: Six level evaluation and grading method Exercise tolerance: 6MWT Depression: GDS SpO2: Pulse oximetry device	Baseline, 6m, 9m, 12m	Inpatient and Outpatient
Boxall et al. (2005), Australia， RCT [30]	46	IG:77.60±7.60 CG:75.80±8.10	PR	usual medical care	12w	Exercise tolerance: 6MWT HRQL: SGRQ Dyspnea: Borg Scale Readmission rate: Frequency record	Baseline, 12w	Home-based
Norweg et al. (2005), America, RCT [31]	43	60-92	ETLS； ETAT	exercise training alone	10w	HRQL: CRQ PF: PFSDQ-M Self-efficacy: CSES Exercise tolerance: 6MWT	Baseline, 6w, 12w, 18w, 24w	Outpatient
Zhang & Zhao (2005), China, quasi-experiment [32]	34	66~78	Breathing training	No	6m	Cough, Sputum production, Shortness of breath: Frequency record Degree of respiratory distress: Six level evaluation and grading method PF: Using a PF testing equipment to measure FEV1, FEV1/FVC, FEV1%pred, FVC, MVV, DLCO	Baseline, 6m	Home-based
Phillips et al. (2006), America, RCT [33]	20	IG:71.00±1.00 CG:70.00±2.00	ET program plus RT	ET	8w	Exercise tolerance: 6MWT	Baseline, 8w	Outpatient
Wu et al. (2006), China, quasi-experiment [34]	30	IG:70.30±6.10 CG: 70.30±7.00	Comprehensive respiratory rehabilitation	Conventional treatment	3m	Dyspnea: Borg scale Dyspnea: Borg scale QOL: QOL Rating Scale Using a PF testing system to measure FEV1 and FEV1/FVC, ADL: Spector’s ADL Questionnaire	Baseline, 3m	Inpatient and Home-based
Xiao et al. (2006), China, quasi-experiment [35]	35	61.40±8.60	Oxygen therapy		12m	Intensity of symptoms: SCL-90 Exercise tolerance: Using the duration of continuous walking on level ground until the patient develops significant shortness of breath as the criterion	Baseline, 12m	Outpatient
Xu et al. (2006), China, quasi-experiment [36]	34	78.90±8.50	Exercise training	No	6m	Using a PF testing system to measure FEV1 and FEV1/FVC, FVC, FEV1%pred, MVV, RV, TLC Exercise tolerance: 6MWT Dyspnea: mMRC	Baseline, 6m	Home-based
Lum et al. (2007), China, RCT [37]	75	IG:81.30±5.80 CG:80.20±6.60	Semi-supervised, domiciliary PR (exercise)	Conventional nursing	12w	Exercise tolerance: 6MWT HRQL: SGRQ Depression: GDS Psychological morale: PGMS	Baseline, 12w, 48w	Residing nursing homes
Ke et al. (2009), China, quasi-experiment [38]	6	67.50±5.30	24-Form Style Tai Chi	No	12w	Whole-genome expression: Microarray	Baseline, 12w	Home-based
Santiworakul et al. (2009), Tailand, quasi-experiment [39]	20	IG:70.80±2.66 CG:68.30±11.05	home program of functional exercise	Usual care	8w	PF: Using a spirometry to measure FEV1, FVC Maximum lower extremity muscle strength: Back and leg dynamometer Exercise tolerance: 6MWT	Baseline, 4w, 8w	Home-based
Wu et al. (2009), China, RCT [40]	30	IG:70.50±7.10 CG:70.30±7.00	Exercise training	Conventional treatment	3m	Dyspnea: Borg scale Exercise tolerance: 6MWT PF: Using a PF testing equipment to measure FEV1, FVC, FEV1/FVC	Baseline, 3m	Inpatient and Home-based
Jiang et al. (2011), China, RCT [41]	54	IG1:66.30±5.50 IG2:65.90±5.80 CG:67.60±6.50	IG1: Upper and lower limb exercises IG2: Lower limb exercises alone	No PR	16w	VO2max, VEmax, O2pulsemax, and HRmax: CPET HRQL: SF-36 Dyspnea: Borg scale	Baseline, 16w	Outpatient
Wakabayashi et al. (2011), Japan, RCT [42]	102	IG:72.90±6.40 CG:70.40±8.60	Self-management program	Conventional nursing	6m	Lung Information Needs: LINQ PF: Using a PF testing equipment to measure FEV1, VC, and FVC, FEV1%pred. Dyspnea: mMRC Exercise tolerance: 6MWT BMI: weight (kg)/height (meters2) ADL: ADL scale Disease severity: BODE index HRQL: SGRQ Comorbidities: Charlson index	Baseline, 6m, 12m	Home-based
Zakrisson et al. (2011), Sweden, Cohort study [43]	103	IG:67±4 CG:68±5	Nurse-led multidisciplinary PR program	NR	6w	Exercise tolerance: 6MWT HRQL: CCQ	Baseline, 2m, 5m, 1y	Outpatient
Zhao (2011), China, RCT [44]	100	65-82	IG1: Pursed-Lip and Abdominal Breathing IG2: LiuZiJue IG3: Exercise Prescription	Routine health education	6m	PF: Using a PF testing equipment to measure FEV1%pred, FEV1 Exercise tolerance: 6MWT PaO2, PaCO2: Arterial blood gas analysis	Baseline, 3m, 6m	Home-based
Zhu & Li (2011), China, quasi-experiment [45]	48	80.33±6.45	Health Education Guided by the Health Promotion Model	No	1y	Treatment Adherence: Treatment Adherence Questionnaire Readmission rate: Frequency record	Baseline, 1y	Home-based
Chau et al. (2012), China, RCT [46]	40	IG:73.50±6.05 CG:72.22±6.13	Telecare service for PR	Service for PR	2m	Satisfaction: A self-developed 10-item user satisfaction questionnaire HRQL: CRQ PF: Using a PF testing equipment to measure FEV1, FEV1/FVC. Readmission rate: Frequency record	Baseline, 1m, 2m	Home-based
Jia et al. (2012), China, quasi-experiment [47]	54	74.10±2.80	PR	No	3m	PF: Using a PF testing system to measure FEV1, FEV1/FVC, FEV1%pred, FVC, FVC%pred QOL: QOL Rating Scale BMI: weight (kg)/height (meters2) Exercise tolerance: 6MWT Dyspnea and Fatigue: Borg scale	Baseline, 3m	Outpatient
Shi (2012), China, quasi-experiment [48]	20	IG:67.67±5.025 CG:69.60±6.096	Tai Chi exercise	Conventional care	12w	Exercise tolerance: 6MWT Dyspnea: mMRC PF: Using a PF testing equipment to measure FEV1%pred, MVV, VC, FEV1/FVC, FVC, FEV1 HRQL: CAT Disease severity: BODE index	Baseline, 12w	Community
Wang & Zheng (2012), China, quasi-experiment [49]	63	79.20±4.60	PR	No	6m	Exercise tolerance: 6MWT PF: Using a PF testing equipment to measure VC, FEV1, FEV1/FVC, MMEF, PEF	Baseline, 6m	Inpatient and Home-based
Wu L & Wu S (2012), China, quasi-experiment [50]	60	70.10±3.40	PR Exercise	No	3m	Sleep Quality: PSQI Insomnia status: Frequency record	Baseline, 3m	Home-based
Benton & Wagner (2013), America, quasi-experiment [51]	19	IG:71.00±3.70 CG:69.90±6.30	PR plus Single-set resistance training	PR	8w	HRQL: SF-36 Upper limb muscle strength: One-repetition maximum inclined chest press Lower limb muscle strength: One-repetition maximum seated leg press Exercise tolerance: 6MWT	Baseline, 8w	Inpatient
Liu et al. (2013), China, quasi-experiment [52]	48	67.60±6.30	Integrated Breathing Exercise	No	6m	ADL: BI Degree of respiratory distress: Six level evaluation and grading method	Baseline, 6m	Home-based
Luo et al. (2013), China, RCT [53]	112	IG:67.60±3.20 CG:69.40±3.90	Routine care and treatment, as well as health education	Routine care and treatment	NR	PaO2, PaCO2: Arterial blood gas analysis PF: Using a PF testing equipment to measure FEV1 QOL: QOL Rating Scale	Baseline, 6m	Inpatient
Xing et al. (2014), China, RCT [54]	112	IG1:65.24±8.37 IG2:62.38±6.24 CG:64.48±6.54	IG1: 24-Form Yang-Style Tai Chi IG2: Pursed-Lip Belly Breathing and Brisk Walking	Regular Activities	12w	PF: Using a PF testing equipment to measure FEV1/FVC, FEV1%pred, MVV SaO2: Arterial blood gas analysis	Baseline, 6w, 12w	Home-based
Zhang J & Zhang X (2014), China, RCT [55]	86	IG:67.14±7.11 CG:66.83±6.17	Multidisciplinary Respiratory Rehabilitation Training	Diaphragmatic Breathing, Pursed-Lip Breathing, and Respiratory Muscle Training	1y	HRQL: SGRQ	Baseline, 1y	Inpatient and Outpatient
Zheng (2014), China, RCT [56]	50	IG:71.0±8.406 CG:72.92±5.98	Long-term home oxygen therapy and inhaled drug therapy	Inhaled drug therapy	1y	Disease severity: BODE index	Baseline, 1y	Home-based
Kawagoshi et al. (2015), Japan, RCT [57]	27	IG:74.00±8.00 CG:75.00±9.00	PR and feed back from using a pedometer	PR	1y	Physical activity ability: A tri-axial accelerometer system PF: Using a spirometry to measure FEV1, FVC, and FEV1/FVC QF muscle force: Hydro musculator GT-160 Dyspnea: mMRC Exercise tolerance: 6MWT Disease severity: BODE index HRQL: CRQ	Baseline, 1y	Home-based
Liu et al. (2016), China, quasi-experiment [58]	41	76.07±5.98	Home-based PR	No	12w	Frailty: CHS Frailty Scale, FI Physical activity ability: SPPB Exercise tolerance: 6MWT	Baseline, 12w	Home-based
Sun et al. (2016), China, quasi-experiment [59]	51	IG:70.00±6.00 CG: 69.00±6.00	PR traning	Routine treatment	12w	PF: Using a PF testing equipment to measure FEV1%pred, FEV1/FVC Exercise tolerance: 6MWT Intensity of symptoms: CAT CRP: Immunoturbidimetry Fbg: Von Clauss method TNF-α, IL-6: ELISA	Baseline, 12w	Outpatient
Zakrisson et al. (2016), Sweden, longitudinal quasi-experiment [60]	103	IG:67.30±4.20 CG:68.10±5.10	Nurse-led multidisciplinary PR programme	Usual care	6w	Exercise tolerance: 6MWT HRQL: CCQ Acute exacerbation of COPD: Frequency record	Baseline, 1y, 3y	Outpatient
Alsaraireh & Aloush (2017), Jordan, Cohort study [61]	106	73±9	PR	No	6m	HRQL: SGRQ Depression: Beck Depression Inventory Dyspnea: mMRC Exercise tolerance: 6MWT	Baseline, After PR	Inpatient
Tian et al. (2017), China, RCT [62]	80	IG1:68.46±5.39 IG2:68.10±5.56 CG:68.84±5.14	IG1: MRRT IG2: MRRT and NPPV	Conventional pharmacological treatment and oxygen therapy	12w	VO2max, Wmax: CPET Disease severity: BODE index Dyspnea: mMRC Exercise tolerance: 6MWT HRQL: COPD-QOL Scale PaO2: Arterial blood gas analysis PaCO2: Arterial blood gas analysis	Baseline, 12w	Inpatient and Home-based
Torres-Sánchez et al. (2017), Spain, RCT [63]	58	IG:75.65±6.25 CG:72.12±8.19	A cycling exercise using a pedal exerciser	standard care	NR	QF muscle force: Portable handheld dynamometer Balance Function: One-leg stance test Exercise tolerance: 30-second STS test Number of steps: SenseWear Armband	Baseline, At discharge	Inpatient
Zhong et al. (2017), China, RCT [64]	144	IG:68.63±2.26 CG:68.92±2.31	Peer education, cardiopulmonary rehabilitation therapy	Routine treatment	NR	PF: Using a PF testing equipment to measure FEV1, FEV1/FVC Exercise tolerance: 6MWT HRQL: SGRQ	NR	Inpatient
Bernardi et al. (2018), Italy, quasi-experiment [65]	16	64-85	Home-Based, Moderate-Intensity Exercise Training Using a Metronome	No	12w	Dyspnea: Borg Scale PF: Using a portable spirometry system to measure VE and VT	Baseline, 12w	Home-based
Huang et al. (2018), China, RCT [66]	96	IG:79.00±6.10 CG:77.70±5.50	Early PR intervention	Conventional treatment, and health education	Unclear	PF: Using a PF testing equipment to measure FEV1, FVC, FEV1%pred Dyspnea: mMRC Intensity of symptoms: CAT Exercise tolerance: 6MWT	During hospitalization and at 6 months post-discharge follow-up	Inpatient and Home-based
Mao et al. (2018), China, RCT [67]	40	IG:69.50±3.50 CG:70.20±4.80	Aerobic exercise combined with low-intensity resistance training	Aerobic exercise	12w	PF: Using a cardiopulmonary exercise testing and training system to measure FEV1, FEV1/FVC, FEV1%pred VO2max, AT: CPET Exercise tolerance: 6MWT	Baseline, 12w	NR
Vieira et al. (2018), Brazil, quasi-experiment [68]	7	67.22±6.57	Long-term PR	No	6m	MIP: ATS/ERS respiratory muscle testing Exercise tolerance: 6MWT TNF-α, IL-6, sTNFR1, sTNFR2, IL-1β: ELISA HRQL: SGRQ	Baseline, 6m	NR
Wakabayashi et al. (2018), Japan, Cohort study [69]	136	EG:72.49±5.94 N-EG:76.13±7.27	Home-based exercise using a lower-limb cycle machine	Usual exercise	3y	PF: Using a PF testing equipment to measure FEV1, FVC, VC Dyspnea: mMRC Exercise tolerance: 6MWT BMI: weight (kg)/height (meters2) Disease severity: BODE index Lung Information Needs: LINQ HRQL: SGRQ Comorbidities: Charlson index Acute exacerbation of COPD, Readmission rate: Frequency record	Baseline, 1y, 2y, 3y	Home-based
Alcazar et al. (2019), Spain, RCT [70]	29	IG:77.70±7.90 CG:79.80±6.40	HIIT and power training	Usual care	12w	Physical activity ability: SPPB QOL: EQ-VAS Mid-thigh composition: Computed tomography VL muscle thickness: B-mode ultrasonography SpO2: pulse oximetry device PF: Using a spirometry to measure FEV1, FVC, and FEV1/FVC RFD and MIF: A force plate Pmax: Force-velocity trail Protein carbonylation: 2, 4-DNPH colorimetric method	Baseline, 12w	Outpatient
Chen et al. (2019), quasi-experiment [71]	116	IG:68.80±3.20 CG:69.00±3.40	Abdomial breathing and resistance breathing training	Abdomial breathing	NR	PF: Using a PF testing equipment to measure FEV1, FVC, FEV1/FVC PaO2: Arterial blood gas analysis PaCO2: Arterial blood gas analysis HRQL: SF-36	Baseline, After intervention	Inpatient
Cui et al. (2019), China, quasi-experiment [72]	88	IG1:68.46±5.39 IG2:68.67±5.42 CG:67.84±5.53	IG1: NIPPV + conventional medicine treatment + oxygen therapy IG2: NIPPV + conventional medicine treatment + oxygen therapy + multidisciplinary comprehensive respiratory rehabilitation	conventional medicine treatment + oxygen therapy	3m	Disease severity: BODE index HRQL: COPD-QOL scale PaO2: Arterial blood gas analysis PaCO2: Arterial blood gas analysis	Baseline, 3m	Inpatient
Liu (2019), China, quasi-experiment [73]	94	NR	PRprogram based on 5A model	Conventional care	6m	Disease Knowledge: COPD Knowledge Questionnaire Self-efficacy: CSES Intensity of symptoms: CAT Disease severity: BODE index	Baseline, 3m, 6m	Inpatient and Home-based
van Dam et al. (2019), the Netherlands, Cohort study [74]	158	EG:70.20±8.50 N-EG:71.30±7.60	Geriatric rehabilitation program for COPD	Usual care	6w	HRQL: CCQ Acute exacerbation of COPD: Frequency record ADL: BI Exercise tolerance: 6MWT	Baseline, 3m	Inpatient
Cao & Wang (2020), China, RCT [75]	45	IG:75.23±3.25； CG:74.95±3.15	Routine nursing+rehabilitation education	Routine nursing	NR	Disease knowledge: COPD-Q SCA: ESCA	Baseline, 1m, 3m	Home-based
Chen (2020), China, experiment [76]	53	IG:69.44±2.65 CG:68.50±4.07	Home-based PR combined with balance training	Home-based PR	3m	Balance Function: BBS Balance Confidence: Activities-specific Balance Confidence Scale Exercise tolerance: 6MWT	Baseline, 3m	Inpatient
Iwakura et al. (2020), Japan, Cohort study [77]	69	75±6	Home-based RP	No	3m	QF muscle force: Hydro musculator GT-160 Inspiratory muscle strength: Respiratory manometer Dyspnea: mMRC Exercise tolerance: 6MWT HRQL: CRQ	Baseline, 3m	Home-based
Jiang et al. (2020), China, RCT [78]	106	IG:68.32±4.25 CG:69.03±4.19	Pulmonary Internet Explorer Rehabilitation	Outpatient face to face intervention	3m	Intensity of symptoms: CAT HRQL: SGRQ Exercise self-efficacy: Ex-SRES Dyspnea: mMRC	Baseline, 3m, 6m	Home-based
Jung et al. (2020), United Kingdom, quasi-experiment [79]	10	63-75	Combine Virtual reality with PR	No	8w	HRQL: CRQ Physical activity ability: SPPB Frailty: Edmonton Frail Scale Depression: PHQ-9 Anxiety: GAD-7 Patient Activation: PAM	Baseline, 8w	Home-based
Khosravi et al. (2020), Iran, RCT [80]	60	IG:70.25±7.50 CG:71.79±10.25	Comprehensive care program (respiratory rehabilitation)	Usual care	6m	ATT: ATT questionnaire Intensity of symptoms: CAT Readmission rate: Frequency record	Baseline, 1m, 3m, 6m	Inpatient, Home-based
Li (2020), China, RCT [81]	47	IG:67.00±4.98 CG:68.25±4.34	Respirator-assisted lip-shrinking traning	Traditional lip-shrinking training	8w	Exercise tolerance: 6MWT Intensity of symptoms: CAT Dyspnea: mMRC PF: Using a PF testing equipment to measure FEV1%pred, FEV1/FVC	Baseline, 8w	Outpatient
Liu & Zhang (2020), China, RCT [82]	81	IG:75.20±2.50 CG:75.40±2.70	Loaded deep breathing exercises combined with aerobic exercise	Conventional pulmonary rehabilitation training	3m	PF: Using a PF testing equipment to measure FVC, FEV1/FVC, MVV, MIP, MEP, SVC Exercise tolerance: 6MWT Dyspnea: mMRC T-lymphocyte subsets: CD3+、CD4+、 CD4+/CD8+: Flow cytometry assay	Baseline, 3m	Inpatient and Home-based
Lu et al. (2020), China, RCT [83]	72	IG:67.40±7.10 CG:68.30±6.80	Zheng’s supine rehabilitation exercise	Routine medical treatment	admission and 8 weeks after discharge	PF: Using a PF testing equipment to measure FEV1%pred, FEV1/FVC, FVC, IC, PEF, FEV1 Exercise tolerance: 6MWT Intensity of symptoms: CAT Dyspnea: mMRC	Baseline, at discharge, in the 9th week after discharge	Inpatient and Home-based
Xu et al. (2020), China, RCT [84]	140	IG:78.59±5.41 CG:78.81±5.36	Comprehensive PR Nursing	Routine nursing	NR	PF: Using a PF testing equipment to measure FEV1, FEV1/FVC HRQL: SGRQ	NR	Inpatient
Doucet et al. (2021), Canada, quasi-experiment [85]	7	73.71±8.96	students in health care fields led PR	No	8w	Exercise tolerance: 6MWT HRQL: SGRQ Health Status: Self-Reported Health Status	Baseline, 8w	Outpatient
Feng et al. (2021), China, RCT [86]	124	IG:69.50±6.00 CG: 68.10±5.50	BioMaster virtual scenario intemctive rehabilitation with combined breahing training	conventional nursing intervention	NR	PF: Using a PF testing equipment to measure FEV1, FEV1/FVC, PEF Anxiety: SAS Depression: SDS Exercise tolerance: 6MWT Intensity of symptoms: CAT Cognitive function: MoCA	Baseline, After intervention	Inpatient and Home-based
Jiang (2021), China, quasi-experiment [87]	70	60-75	Self-service PR training	Health education and community routine COPD intervention	16w	PR Exercise Adherence: PR Exercise Adherence Questionnaire Upper Limb Muscle Strength: Hand Grip Dynamometer Exercise tolerance: 6MWT Dyspnea: mMRC PF: Using a PF testing equipment to measure FEV1%pred, FEV1/FVC, FVC, FEV1 HRQL: CAT	Baseline, 7w, 16w	Community
Li et al. (2021), China, quasi-experiment [88]	164	IG:74.44±2.84 CG:74.36±2.81	Conventional therapy, aerobic exercise, and PR training	Conventional therapy and aerobic exercise	2m	Exercise tolerance: 6MWT Intensity of symptoms: CAT PaO2, SaO2: Arterial blood gas analysis PF: Using a PF testing equipment to measure FEV1, FEV1/FVC, FVC	Baseline, 2m	Inpatient and Home-based
Stefan et al. (2021), America, Cohort study [89]	197376	EG:74.50±6.10 N-EG:77.00±7.60	PR within 90 days of discharge	No PR/Late PR	NR	Readmission rate: Frequency record	1y	Home-based
Zeng et al. (2021), China, RCT [90]	120	IG:64.20±4.50 CG:65.60±5.00	Using a multifunctional respiratory rehabilitation sputum valve for respiratory muscle exercise based on CG	Symptomatic treatment, sputum guidance, and health education	NR	PF: Using a PF testing system to measure FEV1 and FEV1%pred Intensity of symptoms: CAT Exercise tolerance: 6MWT Acute exacerbation of COPD, Readmission rate, and Death: Frequency record	Baseline, 1m, 2m Acute exacerbation of COPD, readmission rate, and death: 6m	Inpatient
Zhang et al. (2021), China, RCT [91]	86	IG:65.49±5.15 CG:65.55±5.10	Intermediate care model nursing (including health education, psychological care, pulmonary care, respiratory training, and discharge guidance).	Usual care	NR	PF: Using a PF testing equipment to measure FEV1, FEV1/FVC Acute exacerbation of COPD: Frequency record Clinical improvement time for cough, expectoration, wheezing, and shortness of breath: Frequency record Anxiety: SAS Depression: SDS Exercise tolerance: 6MWT Fall: FRA HRQL: SGRQ	Baseline, upon discharge	Inpatient
Zhu et al. (2021), China, RCT [92]	81	IG:72.32±5.26 CG:72.54±4.91	CBR and outpatient rehabilitation treatment	Outpatient rehabilitative treatment	NR	Self-efficacy: CSES QOL: WHOQOL-BREF	Baseline, 1m, 3m, 6m	Outpatient
Luo et al. (2022), China, quasi-experiment [93]	23	69.25±5.52	Mindfulness-based stress reduction and exercise training	No	6w	Sleep duration, Proportion of REM, proportions of NREM stage 1, NREM stage 2, and NREM stage 3, number of microarousals: Wristband-type sleep monitoring device LSaO2, ODI, Hypoxic Ratio: Wristwatch-type pulse oximeter Sleep Quality: PSQI	Baseline, 6w	Outpatient
Qi et al. (2022), China, RCT [94]	94	IG:69.83±3.23 CG:69.54±3.37	PR Exercise Therapy	Standard Aerobic Exercise	3m	PF: Using a PF testing equipment to measure FVC, FEV1/FVC, MVV Disease severity: BODE index Exercise tolerance: 6MWT PaO2: Arterial blood gas analysis PaCO2: Arterial blood gas analysis HRQL: CCQ	Baseline, 3m	Inpatient and Home-based
Shen et al. (2022), China, RCT [95]	100	IG:67.28±6.43 CG:68.27±5.06	An interactive goal-attainment PR program based on CG	Conventional staged respiratory training and aerobic exercise	6m	Dyspnea: mMRC Exercise tolerance: 6MWT HRQL: SGRQ PF: Using a PF testing equipment to measure FEV1, FEV1/FVC, FVC Self-management ability: ESCA	Baseline, 6m	Home-based
Tang et al. (2022), China, RCT [96]	160	IG:69.85±3.34 CG:68.96±3.41	PR exercise and progressive resistance training	PR exercise	12w	Exercise tolerance: 6MWT Intensity of symptoms: CAT PF: Using a PF testing equipment to measure FEV1, FEV1/FVC, FVC HRQL: SGRQ Self-efficacy: General Self-Efficacy Scale Serum levels of pulmonary surfactant protein (SP)-D: ELISA	Baseline, 12w	Inpatient and Home-based
Truumees et al. (2022), America, Cohort study [97]	658	76.58±7.62	A RT-led home COPD disease management program	Usual care	4w	Readmission rate: Frequency record	After PR 30 days, 60 days, 90 days	Home-based
Xia et al. (2022), China, RCT [98]	124	IG1:71.20±8.20 IG2: 68.70±5.90 CG:74.60±4.20	IG1: NIVS based on CG IG2: Antiasthmatic plaster therapy based on IG1	Routine treatment	3m	Exercise tolerance: 6MWT Intensity of symptoms: CAT PF: Using a PF testing equipment to measure FEV1%pred, FEV1/FVC PaO2: Arterial blood gas analysis PaCO2: Arterial blood gas analysis	Baseline, 3m	Inpatient and Home-based
Yang (2022), China, RCT [99]	75	73.73±8.30	WeChat-platform-based continuous PR nursing care	Usual care	3m	KAP Questionnaire on PR for Patients with COPD HRQL: CAT Disease severity: BODE index	Baseline, 2m, 3m	Inpatient and Home-based
Zhang et al. (2022), China, RCT [100]	60	IG:69.41±2.44 CG:69.23±2.42	Occupational therapy combined with resistance training	resistance training	3m	PF: Using a PF testing equipment to measure FEV1, FEV1/FVC, FEV1%pred, FVC, FVC%pred Exercise tolerance: 6MWT ADL: ADL scale HRQL: SF-36	Baseline, 3m	Home-based
Baltasar-Fernandez (2023), Spain, RCT [101]	21	IG:79.00±6.40 CG:73.60±6.30	Power-oriented resistance training plus high-intensity interval training	Usual care	12w	Disease severity: BODE index Physical activity ability: SPPB HRQL: EQ-5D-5L questionnaire PF: Using a spirometer to measure FEV1 FVC, and FEV1/FVC Wmax, VO2peak: CPET RFD and MIF: A force plate VL muscle thickness: B-mode ultrasonography Malondialdehyde level: High-Performance Liquid Chromatography Protein carbonylation: 2, 4-DNPH colorimetric method Catalase activity: Cayman Chemicals assay kit	Baseline, 12w, 13m	Outpatient
Li (2023), China, RCT [102]	104	IG:69.84±5.72 CG:68.74±5.75	Multiple-modality exercise	Conventional care	12w	Exercise tolerance: 6MWT Dyspnea: mMRC Anxiety/Depression: HADS Exercise self-efficacy: Self-effcacy for exercise scale Perception of exercise behavior: Exercise Benefits/Barriers Scale HRQL: CAT	Baseline, 6w, 12w	Inpatient and Home-based
Sun (2023), China, quasi-experiment [103]	100	IG:67.83±4.02 CG:66.49±3.09	PR based on the behavior change wheel theory	Ususl care	At discharge and in the 2m after discharge	Self-efficacy: CSES HRQL: CAT Exercise tolerance: 6MWT Disease Knowledge: COPD Knowledge Questionnaire	Baseline, 1m, 2m	Inpatient
Tan et al. (2023a), China, RCT [104]	56	IG:70.54±6.89 CG:71.38±5.78	Multi component exercise training	Elastic band resistance training	12m	Elbow flexors, Elbow extensors, Knee flexors, and Knee extensors: Isokinetic muscle strength testing device Upper and Lower limb skeletal muscle mass: A body composition analyzer	Baseline, 1m, 6m, 12m	Inpatient and Home-based
Tan et al. (2023b), China, RCT [105]	59	IG:72.38±6.27 CG:72.86±4.63	Elastic band resistance training	Conventional rehabilitation guidance	12m	Physical activity ability: SPPB Exercise tolerance: 6MWT PF: Using a PF testing equipment to measure FEV1, FVC, MEP Dyspnea: mMRC HRQL: SGRQ	Baseline, 1m, 6m, 12m	Inpatient and Home-based
Zhao (2023), China, RCT [106]	91	IG:62.31±9.72 CG:61.74±8.95	PR care based on the BCW theory	Conventional PR care	NR	PF: Using a PF testing equipment to measure FEV1%pred, FEV1/FVC Exercise tolerance: 6MWT Dyspnea: mMRC HRQL: CAT	Baseline, at discharge, and 1m after discharge	Inpatient
Zong et al. (2023), China, RCT [107]	90	IG1:80.50±1.40 IG2:81.10±2.20 CG:85.90±0.90	IG1: Low-intensity exercise program and ONS IG2: Low-intensity exercise program	Regular health education	12w	Upper Limb Muscle Strength: Hand Grip Dynamometer Exercise tolerance: 6MWT Anxiety/Depression: HADS PF: Using a PF testing equipment to measure FEV1, FVC, MIP, MEP Intensity of symptoms: CAT Dyspnea: mMRC BMI: weight (kg)/height (meters2) FFM, FM, ASM: Multi-frequency bioelectrical impedance analyzers	Baseline, 12w	Inpatient
Dodange et al. (2024), Iran, RCT [108]	60	NR	Receive 4 weeks of DB first, followed by 4 weeks of PLB	Receive 4 weeks of PLB first, followed by 4 weeks of DB	8w	Cognitive function: Abbreviated Mental Test (AMT) Intensity of symptoms: CAT Obstructive sleep apnea: STOP-BANG questionnaire Sleep Quality: PSQI	Baseline, 8w	Inpatient
Jiang (2024), China, RCT [109]	116	IG:67.07±3.00 CG:65.95±3.29	Progressive time-selective Baduanjin training and Conventional care	Conventional care	4w	Exercise tolerance: 6MWT Dyspnea: mMRC HRQL: CAT PF: Using a PF testing equipment to measure FEV1%pred, FEV1/FVC, FVC, FEV1	Baseline, 1w, 4w	Inpatient
Jiang et al. (2024), China, RCT [110]	78	IG:73.36±6.88 CG:74.58±6.09	Remote PR based on patient decision aid	PR	3m	HRQL: SGRQ Dyspnea: mMRC Exercise self-efficacy: Ex-SRES Disease knowledge: COPD-Q PR Knowledge: 9-PRKQ Decision self-efficacy: DSES Decision conflict: DCS Decision regret: DRS	Baseline, 1m, 3m	Home-based
Lian et al. (2024), China, RCT [111]	60	IG:71.24±5.15 CG:70.04±6.13	PR Training	PR Health Education and Nutritional Counseling	12w	PF: Using a PF testing equipment to measure FEV1, FEV1/FVC, FEV1%pred, FVC PaO2, PaCO2, SaO2: Arterial blood gas analysis Exercise tolerance: 6MWT Upper Limb Muscle Strength: Hand Grip Dynamometer Lower limb muscle strength: 5-STS Dyspnea: mMRC Intensity of symptoms: CAT Balance Function: BBS	Baseline, 12w	Home-based
Shan (2024), China, RCT [112]	94	IG:71.55±4.80 CG:71.51±5.52	Enhanced External Counter Pulsation and breathing training	breathing training	12w	PF: Using a PF testing equipment to measure FEV1%pred, FEV1/FVC, FVC, PEF Exercise tolerance: 6MWT Dyspnea: mMRC HRQL: SGRQ	Baseline, 12w	Inpatient
Shiraishi et al. (2024), Japan, RCT [113]	33	IG:76.00±3.00 CG:76.00±4.00	Outpatient PR, Home-based IMT and exercise programme	Outpatient PR and Home exercise programme	12w	DE: Ultrasonography IC, VO2peak, VE, VE/VCO₂, VT/IC, Ti/Ttot, VTI, VTE, and MIP: CPET Exercise tolerance: 6MWT Dyspnea and Fatigue: Borg Scale Intensity of symptoms: CAT	Baseline, 12w	Home-based
Xu et al. (2024), China, RCT [114]	60	IG:72.5（69.25, 76.75） CG: 69.5（66.25, 76.75）	comprehensive home-based PR	Routine care	6m	Dyspnea: mMRC Exercise tolerance: 6MWT HRQL: SGRQ	Baseline, 3m, 6m	Home-based
Zhang (2024), China, RCT [115]	88	IG:68.84±6.73 CG:69.05±6.68	Continuous nursing intervention combined with breathing training guidance	Conventional nursing	NR	PF: Using a spirometer to measure FEV1 and FVC QOL: GQOLI-74 ADL: BI Happiness: MUNSH SCA: ESCA	For ADL: Baseline, 1m, 3m, 6m For PF, QOL, Happiness, SCA: Baseline, After intervention	Inpatient, Home-based
Zhang & Xu (2024), China, RCT [116]	120	IG:71.32±4.25 CG:71.03±3.56	Respiratory rehabilitation exercises and progressive resistance training	Respiratory rehabilitation exercises	8w	PF: Using a PF testing equipment to measure FEV1/FVC, FEV1%pred, FVC Exercise tolerance: 6MWT, 30-second STS test DTei, DE, DTee: Portable ultrasonic doppler blood flow detector Dyspnea: mMRC Intensity of symptoms: CAT HRQL: SGRQ Acute exacerbation of COPD, Readmission rate: Frequency record	Baseline, 8w	Inpatient
Fu et al. (2025), China, RCT [117]	77	IG:64.56±2.43 CG:64.68±2.47	Somatosensory exercise based on artificial intelligence technology	Standard medical treatment, health education, and guidance on home-based PR training.	12w	PF: Using a PF testing equipment to measure FEV1, FEV1/FVC, FVC Dyspnea: mMRC Upper limb muscle strength: 30-second forearm curl test Lower limb muscle strength: 30-second STS test Upper limb flexibility: Back-scratch stretch test Balance capacity: 2.44-meter shuttle walk test Exercise tolerance: 6MWT Intensity of symptoms: CAT	Baseline, 12w	Home-based
Li & Sun (2025), China, RCT [118]	116	IG:64.30±2.32 CG:64.37±2.32	Group progressive resistance training for PR	Routine rehabilitation training	4w	Training Compliance: Self made Training Compliance Scale VO2max, VEmax, O2pulsemax, and HRmax: CPET IL-8, IL-18, IL-6, and IL-12: ELISA Dyspnea: mMRC	Baseline, 2w, 4w	Inpatient
Wang et al. (2025), China, RCT [119]	58	IG:70.93±8.43 CG:71.35±7.72	Pharmacological treatment and comprehensive pulmonary rehabilitation	Pharmacological treatment	12w	Interleukin (IL)-6, IL-8, (TNF)-α、NO, Endothelin (ET)-1: ELISA PF: Using a cardiopulmonary exercise testing and training System to measure FEV1, FEV1/FVC, FEV1%pred, IC%pred, VO2max, VEmax, O2pulsemax, Wmax, HRmax , VO2peak, BR, VD/VT peak, EQCO2@AT, EQO2@AT, VE/VCO2 HRQL: SGRQ	Baseline, 12w	Inpatient and Home-based

IG Intervention Group, CG Control Group, EG Exposure group, N-EG Non-exposure group, w week, m month, y year, NR Not Report, ID Intervention Duration, PR pulmonary rehabilitation, 6MWT 6-Minute Walk Test, GDS Geriatrics Depression Score, PGMS Philadelphia Geriatric Morale Score, SGRQ St. George's Respiratory Questionnaire, GQOLI-74 Generic Quality of Life Inventory-74, FEV₁ Forced Expiratory Volume in 1s, FVC Forced Vital Capacity, PF Pulmonary function, BI Barthel Index, MUNSH Memorial University of Newfoundland Scale of Happiness, BMI Body Mass Index, ESCA Exercise of Self-Care Agency Scale, SCA Self-care ability, LINQ Lung Information Needs Questionnaire, VC Vital Capacity, mMRC modified Medical Research Council Dyspnea Scale, HRQL Health-related quality of life, BODE Body mass index, Obstruction, Dyspnea, and Exercise capacity, CBR Community-based rehabilitation, CSES COPD Patient Self-Efficacy Scale, QOL Quality of Life, WHOQOL-BREF World Health Organization Quality of Life Measurement Scale, ATT adherence-to-treatment, CAT COPD Assessment Test, CRQ Chronic Respiratory Questionnaire, FEV₁%pred Forced Expiratory Volume in 1s as a Percentage of Predicted Value, FVC%pred Forced Vital Capacity as a Percentage of Predicted Value, Ex-SRES Exercise Self-regulatory Efficacy Scale, SPPB Short Physical Performance Battery, PHQ-9 Patient Health Questionnaire-9, GAD-7 Generalized Anxiety Disorder-7, PAM Patient Activation Measure, STS Sit-to-Stand, VE minute ventilation volume, VT minute ventilation tidal volume, PFSDO-M Pulmonary Functional Status and Dyspnea Questionnaire, ETLS Exercise Training plus a Lecture Series, ETAT Exercise Training plus activity training, HIIT High-intensity Interval Training, EQ-VAS EQ visual analogue scale, VL Vastus Lateralis, SpO₂ peripheral capillary oxygen saturation, MIF Maximal Isometric Force, RFD Rate of Force Development, P_max Maximal muscle power, ET endurance-based PR program, RT Resistance Training, CSA Cross-sectional Area, MRI Magnetic Resonance Imaging, VE_max Maximum exercise ventilation, VO_2max Maximum oxygen uptake, HR_max Maximum Heart Rate, O_2plusmax Maximum oxygen pulse, DNPH dinitrophenylhydrazine, CPET Cardiopulmonary Exercise Testing, IL Interleukin, COPD-Q Chronic Obstructive Pulmonary Disease Knowledge Questionnaire, 9-PRKQ 9-item Pulmonary Rehabilitation Knowledge Questionnaire, DSES Decision Self-Efficacy Scale, DCS Decision Conflict Scale, DRS Decision Regret Scale, DE Diaphragmatic excursion, IC Inspiratory Capacity, VO₂ Oxygen uptake, VE minute ventilation, VE/VCO₂ Ventilatory equivalents for carbon dioxide, peak Ti/Ttot Inspiratory time-to-total respiratory cycle time, VTI Inspiratory Tidal Volume, VTE Expiratory Tidal Volume, QF quadriceps femoris, MMEF Maximal Mid-Expiratory Flow, PEF Peak Expiratory Flow, SF-36 36-Item Short Form Health Survey, MVV Maximum Voluntary Ventilation, DLCO Diffusing Capacity of the Lung for Carbon Monoxide, SaO₂ Arterial Oxygen Saturation, ADL Activities of Daily Living, REM Rapid eye movement sleep, LSaO₂ Lowest oxygen saturation, ODI Oxygen desaturation index, PSQI Pittsburgh Sleep Quality Index, OCD oxygen cost diagram, ONS Oral nutritional supplement, HADS Hospital Anxiety and Depression Scale, FFM Fat-Free Mass, FM Fat Mass, ASM Appendicular Skeletal Muscle, CCQ Clinical COPD Questionnaire, BBS Berg Balance Scale, FI Frailty Index, DTei Diaphragm thickness at end-inspiration, DTee Diaphragm thickness at end-expiration, SAS Self-Rating Anxiety Scale, SDS Self⁃Rating Depression Scale, FRA Falls Risk Assessment, MoCA Montreal Cognitive Assessment, MIP Maximum Inspiratory Pressure, MEP Maximum Expiratory Pressure, SVC Slow Vital Capacity, AT Anaerobic Threshold, NPPV non-invasive positive pressure ventilation, W_max Maximum exercise power, MRRT Multidisciplinary Respiratory Rehabilitation Training, RV Residual Volume, TLC Total Lung Capacity, SCL-90 Symptom Checklist-90, TNF Tumor Necrosis Factor, NO Nitric Oxide, ELISA Enzyme-Linked Immunosorbent Assay, IC%pred Percentage of Inspiratory Capacity to Predicted Value, VO₂peak Peak Oxygen Uptake, VO₂%peak Percentage of Predicted Peak Oxygen Uptake, VO₂/kg peak Peak Oxygen Uptake per Kilogram of Body Weight, BR Breathing Reserve, VD/VT Dead Space to Tidal Volume Ratio, EQCO₂@AT CO₂ Ventilatory Equivalent at Anaerobic Threshold, EQO₂@AT O₂ Ventilatory Equivalent at Anaerobic Threshold, NIVS Non-invasive ventilatory support, CRP C-reactive protein, Fbg Fibrinogen, IC inspiratory capacity, DB Diaphragmatic breathing, PLB Pursed-lip breathing, sTNFR Soluble tumor necrosis factor receptor, KAP Knowledge, Attitude, and Practice, RT Respiratory Therapist, PFSDQ-M Modified Pulmonary Functional Status and Dyspnea Questionnaire

Classification and statistics of outcome indicators

A total of 95 included studies reported 590 indicators. After merging indicators with identical names and conducting discussions and categorization, 148 types of outcome indicators were identified (Table 2 and Fig. 2). The number of indicators per study ranged from 1 to 58. Specifically, there were 93 Physiological/Clinical indicators (383 occurrences, 64.92%), 26 Functional status indicators (107, 18.31%), 10 Life impact indicators (79, 13.39%), 14 Psychosocial indicators (33, 5.59%), one of Mortality indicator, and 4 Adverse events indicators (21, 3.56%). Notably, safety outcomes were critically underrepresented: adverse events accounted for only 3.56% of all outcome indicators, and falls and acute exacerbation of COPD were reported in only 1 and 2 studies, respectively. Meanwhile, geriatric-specific outcomes were identified but inconsistently reported; for instance, balance function was assessed in only 3 studies (3.16%), frailty in 2 studies (2.11%), and physical activity ability in 6 studies (6.32%).

Table 2.

Statistics of outcome measures in literature review

Outcome domains	Classification of indicators	Outcome	Frequency	Measurements (frequency)	Measurement time point	Geriatric priority
Physiological/Clinical (92 indicators)	Pulmonary function (15 indicators)	FEV 1	39	Pulmonary function testing device (37), Spirometer (2), CETTS (2)	S/M/L	Widely used; effort-dependent, limited feasibility in frail patients
		FEV 1 /FVC	37	Pulmonary function testing device (35), Spirometer (1), CETTS (2)	S/M/L	Widely used; effort-dependent
		FVC	31	Pulmonary function testing device (29), Spirometer (2)	S/M/L	Widely used; effort-dependent
		FEV 1 %pred	23	FEV 1 %pred = Patient’s observed FEV 1 /Predicted FEV 1 for healthy individuals×100% (23)	S/M/L	Effort-dependent
		MVV	7	Pulmonary function testing device (7)	S/M/L	Limited added value for geriatric assessment
		Peak Expiratory Flow (PEF)	4	Pulmonary function testing device (4)	S/M	Effort-dependent
		VC	4	Pulmonary function testing device (4)	M/L	Slow VC preferred over FVC in elderly
		DLCO	2	Pulmonary function testing device (2)	M/L	Difficult for patients with severe airflow limitation
		FVC%pred	2	Pulmonary function testing device (2)	M	—
		Inspiratory Capacity (IC)	2	Pulmonary function testing device (1), Cardiopulmonary exercise testing (1)	S/M	Relevant for hyperinflation assessment
		RV	1	Pulmonary function testing device (1)	M	—
		SVC	1	Pulmonary function testing device (1)	M	Preferred for elderly; less effort-dependent
		TLC	1	Pulmonary function testing device (1)	M	—
		IC%pred	1	CETTS (1)	M	—
		MMEF	1	Pulmonary function testing device (1)	M	—
	Blood gas parameters (3 indicators)	PaO2	9	Arterial blood gas analysis (9)	M	Invasive; pulse oximetry preferred for routine use
		PaCO2	8	Arterial blood gas analysis (8)	M	Relevant for hypercapnic COPD phenotype
		SaO2	4	Arterial blood gas analysis (4)	S/M	Non-invasive pulse oximetry available
	Cardiopulmonary Function (17 indicators)	VO2max	4	Cardiopulmonary exercise testing (4)	S/M	Gold standard but demanding; limited in very frail
		Maximum Heart Rate (HRmax)	3	Cardiopulmonary exercise testing (2), Cardiopulmonary exercise testing and training system (CETTS) (1)	S/M	—
		VEmax	3	Cardiopulmonary exercise testing (2), CETTS (1)	S/M	—
		Oxygen uptake (VO2) peak	3	Cardiopulmonary exercise testing (2), CETTS (1)	M/L	Requires maximal effort
		Wmax	3	Cardiopulmonary exercise testing (2), CETTS (1)	M	—
		O2plusmax	2	Cardiopulmonary exercise testing (1), CETTS (1)	M	—
		VE	2	A portable spirometry system (1), Cardiopulmonary exercise testing (1)	M	—
		VE/VCO₂	2	Cardiopulmonary exercise testing (1), CETTS (1)	M	—
		AT	1	Cardiopulmonary exercise testing (1)	M	—
		EQCO2@AT	1	CETTS (1)	M	—
		EQO2@AT	1	CETTS (1)	M	—
		Ti/Ttot	1	Cardiopulmonary exercise testing (1)	M	—
		VD/VT peak	1	CETTS (1)	M	—
		VT	1	A portable spirometry system (1)	M	—
		VTE	1	Cardiopulmonary exercise Testing (1)	M	—
		VTI	1	Cardiopulmonary Exercise Testing (1)	M	—
		VT/IC	1	Cardiopulmonary Exercise Testing (1)	M	—
	Respiratory mechanics indicators (8 indicators)	Diaphragmatic excursion (DE)	2	Portable ultrasonic doppler blood flow detector (1), Ultrasonography (1)	S/M	—
		SpO2	2	Pulse oximetry device (2)	M/L	Non-invasive; recommended for routine monitoring
		BR	1	CETTS (1)	M	—
		DTee	1	Portable ultrasonic doppler blood flow detector (1)	S	—
		DTei	1	Portable ultrasonic doppler blood flow detector (1)	S	—
		Hypoxic ratio	1	Wristwatch-type pulse oximeter (1)	S	—
		ODI	1	Wristwatch-type pulse oximeter (1)	S	—
		LSaO2	1	Wristwatch-type pulse oximeter (1)	S	—
	Inflammatory Indicators (8 indicators)	Interleukin (IL)−6	3	Enzyme linked immunosorbent assay (3)	S/M	Volatile; limited clinical utility in routine PR
		Tumor Necrosis Factor (TNF)-α	3	Enzyme linked immunosorbent assay (3)	M	Volatile; limited clinical utility
		IL-8	2	Enzyme linked immunosorbent assay (2)	S/M	—
		IL-1β	1	Enzyme linked immunosorbent assay (1)	M	—
		IL-12	1	Enzyme linked immunosorbent assay (1)	S	Infrequently reported
		IL-18	1	Enzyme linked immunosorbent assay (1)	S	Infrequently reported
		CRP	1	Immunoturbidimetry (1)	M	—
		Fibrinogen	1	Von Clauss method (1)	M	—
	Symptoms/Signs (24 indicators)	Dyspnea	36	modified Medical Research Council Dyspnea Scale (27), Borg Scale (8), Borgoxygen cost diagram (1)	S/M/L	Core symptom; mMRC simple and validated in elderly
		Intensity of symptoms	16	CAT (15), Symptom Checklist-90 (1)	S/M	CAT: validated PROM; feasible in most older adults
		Disease severity	11	Body mass index, Obstruction, Dyspnea, and Exercise capacity (BODE) index (11)	M/L	Composite index; strong prognostic value
		BMI	4	weight (kg)/height (meters2) (4)	M/L	Simple; relevant for sarcopenia screening
		Degree of respiratory distress	3	Six level evaluation and grading method (3)	S/M/L	—
		Fatigue	2	Borg Scale (2)	M	Key symptom; use validated PROMs
		VL muscle thickness	2	B-mode ultrasonography (2)	M/L	—
		Cough	2	Frequency record (2)	M/L	—
		Shortness of breath	2	Frequency record (2)	M/L	—
		Sputum production	2	Frequency record (2)	M/L	—
		Fat-free mass (FFM)	1	Multi-frequency bioelectrical impedance analyzers (1)	M	Relevant for sarcopenia assessment
		Fat mass	1	Multi-frequency bioelectrical impedance analyzers (1)	M	—
		Upper limb skeletal muscle mass	1	A body composition analyzer (1)	S/M/L	—
		ASM	1	Multi-frequency bioelectrical impedance analyzers (1)	M	Relevant for sarcopenia diagnosis
		CSA of quadriceps	1	Magnetic Resonance Imaging (1)	M	—
		Insomnia status	1	Frequency record (1)	M	—
		Obstructive sleep apnea	1	STOP-BANG questionnaire (1)	S	Relevant; COPD-OSA overlap syndrome
		Lower limb skeletal muscle mass	1	A body composition analyzer (1)	S/M/L	—
		Mid-thigh composition	1	Computed tomography (1)	M	—
		Clinical improvement time for cough	1	Frequency record (1)	S	—
		Clinical improvement time for expectoration	1	Frequency record (1)	S	—
		Clinical improvement time for shortness of breath	1	Frequency record (1)	S	—
		Clinical improvement time for wheezing	1	Frequency record (1)	S	—
		Sleep duration	1	Wristband-type sleep monitoring device (1)	S	—
	Metabolic and oxidative stress indicators (6 indicators)	Protein carbonylation	2	2, 4-DNPH colorimetric method (2)	M/L	—
		Catalase activity	1	Cayman Chemicals assay kit (1)	M/L	—
		Malondialdehyde level	1	High-Performance Liquid Chromatography (1)	M/L	—
		Endothelin-1	1	Enzyme linked immunosorbent assay (1)	M	—
		Nitric Oxide	1	Enzyme linked immunosorbent assay (1)	M	—
		Serum levels of pulmonary (SP)-D	1	Enzyme linked immunosorbent assay (1)	M	—
	Immune indicators (5 indicators)	CD3+	1	Flow cytometry assay (1)	M	—
		CD4+	1	Flow cytometry assay (1)	M	—
		CD4+/CD8+	1	Flow cytometry assay (1)	M	—
		sTNFR 1	1	Enzyme linked immunosorbent assay (1)	M	—
		sTNFR 2	1	Enzyme linked immunosorbent assay (1)	M	—
	Sleep structure (5 indicators)	Number of microarousals	1	Wristband-type sleep monitoring device (1)	S	—
		Proportions of NREM stage 3	1	Wristband-type sleep monitoring device (1)	S	—
		Proportions of NREM stage 1	1	Wristband-type sleep monitoring device (1)	S	—
		Proportions of NREM stage 2	1	Wristband-type sleep monitoring device (1)	S	—
		Proportions of REM	1	Wristband-type sleep monitoring device (1)	S	—
	Genetic level (1 indicator)	Whole-genome expression	1	Microarray (1)	S	—
Functional status (27 indicators)	Exercise capacity (5 indicators)	Exercise tolerance	58	6-Minute Walk Test (6MWT) (54), 30-second Sit-to-Stand (STS) test (3), Using the duration of continuous walking on level ground until the patient (1)	S/M/L	Gold standard; feasible in most older adults
		Physical activity ability	6	Short Physical Performance Battery (SPPB) (5), A tri-axial accelerometer system (1)	M/L	Essential geriatric vital sign; major gap
		Balance function	3	One-leg stance test (1), Berg Balance Scale (2)	S/M	Critical for fall prevention; severely under-reported
		Gait speed	1	30 m track (1)	M	Strong prognostic marker in elderly
		Number of steps	1	SenseWear Armband (1)	S	—
	Muscle function and strength (18 indicators)	Upper limb muscle strength	5	Hand Grip Dynamometer (3), 30-second forearm curl test (1), One-repetition maximum inclined chest press (1)	S/M	Handgrip: simple, validated, strong prognostic value
		Upper limb flexibility	1	Back-scratch stretch test (1)	M	—
		Elbow extensors	1	Isokinetic muscle strength testing device (1)	S/M/L	—
		Elbow flexors	1	Isokinetic muscle strength testing device (1)	S/M/L	—
		Lower limb muscle strength	3	30-second STS test (1), 5-STS (1), One-repetition maximum seated leg press (1)	S/M	STS: low-ceiling, prognostic; highly recommended
		Quadriceps femoris muscle force	3	Hydro musculator GT-160 (2), Portable handheld dynamometer (1)	S/M/L	—
		Maximal isometric force	2	A force plate (2)	M/L	—
		RFD	2	A force plate (2)	M/L	—
		Maximum inspiratory pressure (MIP)	4	Pulmonary function testing device (2), ATS/ERS respiratory muscle testing (1), Cardiopulmonary exercise testing (1)	M	Effort-dependent; limited in very frail
		MEP	3	Pulmonary function testing device (3)	S/M/L	—
		Inspiratory muscle strength	1	Respiratory manometer (1)	M	—
		Isometric knee extension peak	1	Kin-Com dynamometer (1)	M	—
		Isokinetic knee extension peak	1	Kin-Com dynamometer (1)	M	—
		Knee extensors	1	Isokinetic muscle strength testing device (1)	S/M/L	—
		Knee flexors	1	Isokinetic muscle strength testing device (1)	S/M/L	—
		Leg extension power	1	Nottingham Power Rig (1)	M	—
		Maximum lower extremity muscle strength	1	Back and leg dynamometer (1)	S	—
		Pmax	1	Force-velocity trail (1)	M	—
	Cognition and frailty (2 indicators)	Cognitive function	2	Montreal Cognitive Assessment (MoCA) (1), Abbreviated Mental Test (AMT) (1)	S	Relevant for PR education and adherence
		Frailty	2	Edmonton Frail Scale (1), CHS Frailty Scale/Frailty Index (1)	M	Major geriatric gap; predicts PR response and prognosis
	-	Health Status	1	Self-Reported Health Status (1)	S	—
	-	Pulmonary function	1	Modified Pulmonary Functional Status and Dyspnea Questionnaire (1)	S/M	—
Life impact (10 indicators)	-	Health-related quality of life	43	St.George’s Respiratory Questionnaire (20), Chronic Respiratory Questionnaire (5), COPD Quality of Life Scale (2), COPD Assessment Test (CAT) (7), Clinical COPD Questionnaire (4), 36-Item Short Form Health Survey (4), EQ-5D-5 L questionnaire (1)	S/M/L	Core PROM; SGRQ and CAT best validated in COPD
		ADL	11	ADL Scale (6), Barthel Index (3), Spector’s ADL Questionnaire (2)	M/L	Fundamental for geriatric independence
		Quality of life	8	QOL Rating Scale (5), Generic Quality of Life Inventory-74 (1), World Health Organization Quality of Life Measurement Scale (1), EQ visual analogue scale (1)	S/M/L	—
		Adherence	4	PR Exercise Adherence Questionnaire (2), Treatment Adherence Questionnaire (2)	S/M/L	Key determinant of PR success
		Disease knowledge	4	Chronic Obstructive Pulmonary Disease Knowledge Questionnaire (2), COPD Knowledge Questionnaire (2)	S/M	Relevant for self-management education
		Sleep quality	3	Pittsburgh Sleep Quality Index (3)	S/M	Under-recognised geriatric domain; affects adherence
		Lung Information Needs	2	Lung Information Needs Questionnaire (2)	M/L	—
		Satisfaction	2	A self-developed user satisfaction questionnaire (2)	S	Needs validated scale (e.g., CSQ-8)
		KAP of PR	1	KAP Questionnaire on PR for Patients with COPD (1)	S/M	—
		PR Knowledge	1	9-item Pulmonary Rehabilitation Knowledge Questionnaire (1)	S/M	—
Adverse events (4 indicators)	-	Readmission rate	11	Frequency record (11)	M/L	Key healthcare utilisation metric
		Acute exacerbation of COPD	7	Frequency record (7)	M/L	Core safety indicator
		Comorbidities	2	Charlson index (2)	M/L	Relevant for risk stratification
		Fall	1	Falls Risk Assessment (1)	S	Mandatory safety outcome; critically absent
Psychosocial (14 indicators)	-	Depression	9	Geriatrics Depression Score (2), Self-rating Depression Scale (2), Patient Health Questionnaire-9 (1), Beck Depression Inventory (2), Hospital Anxiety and Depression Scale (2)	S/M	Common comorbidity; use geriatric-validated tools
		Anxiety	5	Self-Rating Anxiety Scale (2), Generalized Anxiety Disorder-7 (1), Hospital Anxiety and Depression Scale (2)	S/M	Often co-occurs with depression
		Self-efficacy	5	COPD Patient Self-Efficacy Scale (4), General Self-Efficacy Scale (1)	S/M/L	Key predictor of exercise adherence
		Exercise self-efficacy	3	Exercise Self-regulatory Efficacy Scale (2), Self-effcacy for exercise scale (1)	S/M/L	—
		Self-care ability	2	Exercise of Self-Care Agency Scale (2)	S/M	—
		Balance Confidence	1	Activities-specific Balance Confidence Scale (1)	M	Relevant for fall risk assessment
		Decision conflict	1	Decision Conflict Scale (1)	S/M	—
		Decision regret	1	Decision Regret Scale (1)	S/M	—
		Decision self-efficacy	1	Decision Self-Efficacy Scale (1)	S/M	—
		Happiness	1	MUNSH (1)	M/L	—
		Patient Activation	1	Patient Activation Measure (1)	S	Positive dimension; overlooked
		Perception of exercise behavior	1	Exercise Benefits/Barriers Scale (1)	S	Relevant for self-management
		Psychological morale	1	Philadelphia Geriatric Morale Score (1)	S/M	—
		Self-management ability	1	Exercise of Self-Care Agency Scale (1)	M/L	—
Mortality (1 indicator)	-	Disease-related survival	1	Frequency record (1)	M	—

w week, m month, y year, FEV₁Forced Expiratory Volume in 1 s, CETTS Cardiopulmonary Exercise Testing and Training System, FVC Forced Vital Capacity, FEV₁%pred FEV₁ as a Percentage of Predicted Value, ADL Activities of Daily Living, MVV Maximum Voluntary Ventilation, BMI Body Mass Index, VC Vital Capacity, VO_2maxMaximum Oxygen Uptake, MEP Maximum Expiratory Pressure, VE_maxMaximum exercise ventilation, W_maxMaximum exercise power, DLCO Diffusing Capacity of the Lung for Carbon Monoxide, PaO₂Partial Pressure of Arterial Oxygen, FVC%pred Forced Vital Capacity as a Percentage of Predicted Value, O₂plusmax Maximum oxygen pulse, SpO₂Peripheral capillary oxygen saturation, RFD Rate of Force Development, VL Vastus Lateralis, VE/VCO₂ Ventilatory equivalents for carbon dioxide, AT Anaerobic Threshold, ASM Appendicular Skeletal Muscle, BR Breathing Reserve, CRP C-reactive protein, CSA Cross-sectional Area, DTee Diaphragm thickness at end-expiration, DTei Diaphragm thickness at end-inspiration, EQCO2@AT CO₂ Ventilatory Equivalent at AT, EQO2@AT O₂ Ventilatory Equivalent at AT, MUNSH Memorial University of Newfoundland Scale of Happiness, IC%pred Percentage of Inspiratory Capacity to Predicted Value, KAP Knowledge, Attitude, and Practice, LSaO₂Lowest oxygen saturation, MMEF Maximal Mid-Expiratory Flow, ODI Oxygen desaturation index, P_max Maximal muscle power, NREM Non-Rapid Eye Movement, PR Pulmonary Rehabilitation, RV Residual Volume, SP Surfactant protein, sTNFR Soluble tumor necrosis factor receptor, SVC Slow Vital Capacity, Ti/Ttot Inspiratory time-to-total respiratory cycle time, TLC Total Lung Capacity, VD/VT Dead Space to Tidal Volume Ratio, VT Minute ventilation tidal volume, VTE Expiratory Tidal Volume, VTI Inspiratory Tidal Volume, REM Rapid Eye Movement. Bold = high-frequency tools (≥ 10 studies), indicating common practice. Bold + Italic = geriatric-essential tools that are currently under-reported, indicating best practice/geriatric priority. S = Short-term (≤ 4 weeks); M = Medium-term (1–6 months); L = Long-term (> 6 months)

Fig. 2.

Outcome indicator domains for PR in older adults with COPD

Quality appraisal

The quality of the included cohort studies was deemed moderate to high (scoring 6–9 points) (Appendix B). Meanwhile, the quality assessment results of the included RCTs, quasi-experimental studies and experimental study revealed that 82.50% of the studies were rated as “low risk”, 14.00% as “some concern”, and 3.50% as “high risk” (Fig. 3); Detailed evaluations of bias across five domains—randomization process, deviations from intended interventions, missing outcome data, measurement of outcomes, and selection of reported results—are provided in Appendix C. The quality assessment results of the included quasi-experimental studies and experimental study revealed that 66.00% of the studies were rated as “low risk”, 28.00% as “moderate risk”, and 6.00% as “serious risk” (Fig. 4); Detailed evaluations of bias across seven domains—confounding, selection of participants, classification of interventions, deviations from interventions, missing data, measurement of outcomes, and selection of reported result—are provided in Appendix D.

Fig. 3.

Percentages of items of included RCTs that produced risks of bias

Fig. 4.

Percentages of items of included quasi-experimental studies and experimental studies that produced risks of bias

Discussion

This systematic review comprehensively maps the heterogeneous outcome landscape in PR for older adults with COPD. While confirming the established focus on core domains such as exercise capacity and health-related quality of life, our findings directly address gaps in the existing COS for PR in COPD established by Souto-Miranda et al. [13, 14]. Specifically, that COS did not include balance, physical activity, frailty, or cognitive function—domains that our review identifies as essential for evaluating PR success in older adults. We provide strong empirical evidence that these geriatric-specific priorities must be formally integrated into a future age-specific COS. By systematically detailing the associated measurement instruments, assessment time points, and equipment, this work translates the identified outcome domains into actionable guidance for both clinical practice and research. Consequently, it delivers a necessary empirical foundation for developing an age-specific COS, thereby advancing the standardization and precision of outcome evaluation to better serve the aging COPD population.

The physiological/clinical domain encompasses a wide spectrum of biomarkers and pathophysiological measures. While pulmonary function parameters (e.g., FEV₁, FVC) remain widely reported, their operational utility in older adults is often compromised by technical complexity and variable measurement protocols [120]. The accuracy of spirometry is highly dependent on patient effort and cognition, which can be limiting factors in frail older adults with cognitive impairment or respiratory muscle weakness [121]. Therefore, in routine geriatric PR, we advocate prioritizing simple, performance-based functional tests—such as the Sit-to-Stand (STS) test—over complex spirometry and volatile biomarkers [122]. The STS requires minimal equipment, is effort-independent, and provides a valid, prognostically meaningful assessment of lower limb strength and endurance. Measures of gas exchange (e.g., SpO₂, PaO₂) and cardiopulmonary exercise testing (e.g., VO₂peak, Wₘₐₓ) provide objective assessment of functional reserve but require careful interpretation in the context of age-related decline and multimorbidity. Notably, the emergence of inflammatory markers (e.g., IL-6, TNF-α), oxidative stress parameters (e.g., malondialdehyde), and immune indices reflects a growing interest in elucidating the molecular mechanisms underpinning PR. However, the infrequent reporting of many such biomarkers (e.g., IL-12, IL-18) limits their current validity. Therefore, in routine geriatric PR practice, priority should be given to clinically actionable, minimally invasive measures that can be reliably obtained in older patients with reduced physiological reserve, such as SpO₂ during exercise, over more complex and volatile biomarkers like inflammatory cytokines.

Current PR research demonstrates significant gaps and imbalances across key outcome domains. In the domain of functional status, the 6-Minute Walk Test (6MWT) was frequently employed, while key functional indicators such as balance capacity and physical activity ability received insufficient attention. Given that older COPD patients often present with sarcopenia and balance impairments [123], functional assessments must extend beyond the 6MWT. These indicators are not merely academic additions—they directly fill the gap between standard COPD outcomes and the geriatric realities of frailty and functional dependence highlighted in our Introduction. Measuring physical activity via Short Physical Performance Battery (SPPB) [124] and muscle strength via the STS test [122] or handgrip dynamometry allows clinicians to detect early functional decline, tailor exercise prescriptions, and monitor the very deficits that drive disability in this population. We recommend the routine incorporation of validated tools such as the SPPB [124] for overall physical activity ability, the Berg Balance Scale (BBS) or Timed Up and Go (TUG) test for balance [125]. But for extremely frail older adults in whom even the 6MWT may be infeasible due to severe breathlessness or immobility, the SPPB—and particularly its 5-repetition STS component—serves as a viable, low-ceiling alternative that still provides meaningful prognostic information and can be completed at the bedside [126].

Regarding psychosocial indicators, although depression and anxiety were commonly evaluated, positive psychological dimension, such as well-being, was largely overlooked. This limits a comprehensive understanding of psychosocial well-being in this population. Among psychosocial indicators, self-efficacy and decision conflict were occasionally measured; however, family-level factors, including family support and caregiver burden, were notably absent. A large proportion of informal caregivers of COPD patients experience high burden, anxiety, and fatigue, yet integrating caregivers into home-based PR programmes has been shown to significantly improve these outcomes [127]. Family caregivers are often the primary enablers of PR adherence and long-term maintenance in older adults [128], while family function is the strongest predictor of PR exercise adherence in older adults with COPD [129]. Despite this, family-level outcomes remain invisible in current measurement frameworks. We recommend that future geriatric PR trials incorporate validated caregiver burden scales and family support assessments as core implementation outcomes. Family involvement is a critical resource in the rehabilitation process for older adults [130].

Life impact domain evaluates the broader consequences of COPD and PR on patient’ daily lives. While health-related quality of life (e.g., St.George’s Respiratory Questionnaire, Chronic Respiratory Questionnaire) remains a principal endpoint, its measurement should be complemented by geriatrically salient metrics such as ADL performance, sleep quality (e.g., Pittsburgh Sleep Quality Index), and disease-specific knowledge. The impact of PR on social participation and patient activation levels provides additional insight into its real-world effectiveness [131, 132]. Employing PROMs with established responsiveness in older adults is crucial for capturing the full spectrum of life impact [133].

A patient-centered outcome set for older adults must account for long-term impact and safety. The near absence of mortality data and the use of non-validated, self-designed questionnaires for patient satisfaction in the reviewed literature represent significant oversights. Satisfaction is a key predictor of adherence, especially in older adults. Future studies should incorporate longer-term follow-ups (e.g., 1, 3, or 5 years) for mortality and employ standardized satisfaction scales (e.g., the Client Satisfaction Questionnaire (CSQ) [134] at multiple time points. Similarly, reporting of adverse events was narrow, focusing primarily on exacerbations. Comprehensive safety monitoring in frail older adults must be systematized to include procedure-related tolerance (e.g., oxygen desaturation during exercise) [135], musculoskeletal injuries [136], and most critically, falls [137]. Documenting the type, frequency, and severity of these events is imperative for a realistic risk-benefit assessment of PR in this vulnerable population. Therefore, we call for mortality and falls to be mandated as core safety outcomes in all future geriatric PR trials.

Although resource use (e.g., healthcare costs, hospitalization rates, and outpatient visits) is widely recognized as an important domain in core outcome sets for pulmonary fibrosis [21], it was not identified by indicators in the present review. This is primarily because the studies we included focused on direct patient experiences and clinical physiological measures, whereas resource use pertains more to healthcare system-level evaluation. Future research should consider incorporating “resource use” into broader core outcome sets, particularly when assessing the cost-effectiveness of medical interventions or optimizing healthcare service delivery systems.

The heterogeneity illuminated by this review underscores the inefficiency of the current outcome measurement paradigm. The path forward requires the development and adoption of a COS specifically for older adults with COPD. Based on our findings, such a COS must balance traditional core domains with geriatric priorities. We propose that a minimum reporting set should include exercise capacity (e.g., 6MWT), symptoms (e.g., dyspnea), health-related quality of life, functional status (e.g., SPPB), patient satisfaction, and safety (with reporting of falls). This streamlined set would ensure comparability across studies while forcing the assessment of outcomes that truly matter for the function and well-being of older patients.

Additionally, a proportion of included studies exhibited a high risk of bias in the randomization process, which may affect the internal validity of the primary studies’ efficacy findings. However, the objective of this review was to map the landscape of outcome measurement rather than to synthesize treatment effects. The pattern of outcome indicator use was broadly consistent across studies regardless of risk-of-bias level, supporting the stability of our descriptive conclusions.

Limitations

This review has several limitations. Firstly, while comprehensive, the list may not be exhaustive of all measures used globally, as it was based on a specific set of compiled literature. Secondly, we reported the frequency of outcome usage but did not grade the quality of evidence or the magnitude of change for each measure, which limits our ability to recommend the “best” tools. Thirdly, the outcomes were categorized based on the available data; some classifications could be debated and may require further refinement. Finally, this review provides a static snapshot of outcome use and did not compare the application of outcome measures across different time periods or care settings. A temporal trend analysis (e.g., comparing indicator selection before and after 2015) and a horizontal contrast between inpatient and home-based settings would reveal dynamic changes in outcome priorities and are priorities for future work.

Implications for clinical practice and research

This systematic review provides a foundational evidence base for developing a tailored COS for older adults with COPD undergoing PR. By identifying and structuring commonly used and geriatric-relevant outcome indicators, it equips clinicians and researchers with a framework for selecting multidimensional assessment tools. The consolidation of outcomes across diverse settings supports the standardization of evaluation practices, thereby enhancing the comparability of research findings and facilitating the implementation of evidence-based, personalized rehabilitation strategies.

Conclusion

This systematic review consolidates the heterogeneous outcome landscape in PR for older adults with COPD. While confirming the established focus on exercise capacity and quality of life, it strongly supports the formal integration of geriatric-specific domains—particularly physical activity, balance, and activities of daily living—into future COS. By providing a structured evidence base, this work constitutes a critical step toward a standardized, patient-centered COS for this population. Such standardization will improve the consistency and comparability of research, while the targeted assessment of physical activity and balance will enable truly personalized, function-focused PR tailored to the specific needs of the aging COPD population.

Abbreviations

COPD

Chronic Obstructive Pulmonary Disease

COS

Core Outcome Set

PR

Pulmonary Rehabilitation

COMET

Core Outcome Measures in Effectiveness Trials

PRISMA-COSMIN

Preferred Reporting Items for Systematic Reviews and Meta-Analyses–COnsensus-based Standards for the selection of health Measurement INstruments

RCTs

Randomized Controlled Trials

BBS

Berg Balance Scale

TUG

Timed Up and Go

SPPB

Short Physical Performance Battery

6MWT

6-Minute Walk Test

PROMs

Patient-Reported Outcome Measures

ADL

Activities of Daily Living

CSQ

Client Satisfaction Questionnaire

RoB 2

Version 2 of the Cochrane risk-of-bias tool

ROBINS-I

Risk Of Bias In Non-randomized Studies - of Interventions

NOS

Newcastle-Ottawa Scale

FEV₁

Forced Expiratory Volume in 1s

FVC

Forced Vital Capacity

SpO₂

Peripheral capillary oxygen saturation

PaO₂

Partial Pressure of Arterial Oxygen

VO₂peak

Oxygen uptake peak

Wₘₐₓ

Maximum exercise power

IL

Interleukin

TNF

Tumor Necrosis Factor

Authors' contributions

**Xiao Wan** : Conceptualization, Methodology, Investigation, Data Curation, Formal analysis, Software, Writing - Original Draft, Writing - Review & Editing. **Yunfei Du** : Conceptualization, Methodology, Investigation, Data Curation, Formal analysis, Software, Writing - Review & Editing. **Chi Zhang** : Methodology, Data Curation, Formal analysis. **Guoan Li** : Methodology, Investigation, Supervision. **Xiaoyang Li** : Methodology, Data Curation. **Zeng Cao** : Validation, Supervision. **Jingcan Xu** : Validation, Supervision, Project administration, Funding acquisition, Writing - Review & Editing. **Hui Feng** : Resources, Visualization, Supervision, Project administration, Funding acquisition, Writing - Review & Editing.

Funding

This work was supported by the National Science and Technology Innovation 2030, Noncommunicable Chronic Diseases-National Science and Technology Major Project (Grant No. 2024ZD0524300, 2024ZD0524303).

Data availability

The data that support the findings of the study are available from the corresponding author upon reasonable request.

Declarations

Ethics approval and consent to participate

Not applicable.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.