Incidence and risk factors for postoperative urinary retention in older patients with hip fracture: a scoping review

Abstract

Objectives

This scoping review aimed to synthesise the currently available evidence and influencing factors on the occurrence of postoperative urinary retention (POUR) in older patients with hip fractures.

Design

This scoping review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews guideline.

Data sources

PubMed, Cochrane Library, CINAHL, Web of Science, Chinese National Knowledge Infrastructure, Wanfang Data and Sinomed databases were systematically searched from database inception to 1 September 2024.

Eligibility criteria

We included observational studies reporting on POUR prevalence and risk factors among patients aged 60 years and older with hip fractures and excluded systematic and non-systematic reviews, conference proceedings, editorials, commentaries, qualitative studies and case studies. Duplicated articles and articles unable to access the full text were also excluded. We also excluded studies with populations with pathologic fractures, multiple fractures, treated for periprosthetic fracture, or if studies were published in a language other than English and Chinese.

Data extraction and synthesis

Two authors independently extracted and summarised the data. We summarised the prevalence and risk factors for POUR in older patients with hip fractures.

Results

A total of 106 studies were identified, and 12 studies (all from published literature sources) detailing POUR prevalence and risk factors were included. The studies showed that the incidence of POUR in older patients with hip fractures ranged from 11.10% to 51.33%, and the risk factors included impaired activities of daily living, use of anticholinergic medications, serological indicators (serum albumin and thyroid-stimulating hormone), complications (urinary infection and postoperative incontinence), prolonged indwelling urinary catheters and faecal impaction. In addition, male sex, cognitive impairment, use of opioid medications and coexisting diabetes may also be risk factors for POUR, which still needs to be further clarified

Conclusion

The incidence of POUR in older patients with hip fractures varies widely. Most factors were reported in one study with no proposed underlying mechanism for their influence. Further high-quality studies are needed to validate these findings.

STRENGTHS AND LIMITATIONS OF THIS STUDY.

• This scoping review comprehensively identifies and summarises the incidence and risk factors for postoperative urinary retention in older patients with hip fracture.

• Adherence to Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews guidelines to ensure a rigorous and transparent review process.

• Inclusion of studies published in English and Chinese only.

• No critical appraisal of the quality of included studies, limiting ability to assess the strength of evidence.

Introduction

Hip fractures are common injuries in the geriatric population and are associated with a decline in mobility and functional independence as well as notable morbidity and mortality, with 1-year mortality rates postsurgery ranging between 15% and 36%, with 50% of patients disabled.1,4 Each year, 1.6 million hip fractures occur worldwide, with projected estimates rising to 6 million by 2050.⁵ While surgical management is generally recommended for hip fractures regardless of patient age due to the significant pain and prolonged immobility associated with nonoperative treatment (typically requiring ≥6 weeks of restricted weight-bearing), individual treatment decisions must account for patient-specific factors including comorbidities, functional status and overall goals of care. Surgical management allows patients to ambulate early and minimises potential complications from immobilisation, such as chest infections, venous thromboembolism, pressure ulcers and so on.

Older patients with hip fractures have a high incidence of comorbidities and postoperative complications owing to a generally reduced functional reserve capacity. Postoperative urinary retention (POUR), the most common postoperative complication after hip fracture, is defined as the inability to effectively empty the bladder by spontaneous voiding within 6 hours after hip fracture surgery when the bladder urine volume is greater than 300 mL or the ability to effectively empty the bladder by spontaneous voiding with a residual urine volume greater than 100 mL.⁶ Although mobilisation can be accomplished postoperatively, up to 50% of surgical cases may encounter POUR, which could lead to postoperative delirium, urinary tract infection and late urinary incontinence in older patients with hip fractures, thus prolonging hospitalisation and affecting functional rehabilitation.⁷ Therefore, understanding the factors associated with POUR occurrence and early prevention is essential to promote patient recovery.

Several risk factors for POUR have been identified, including male sex, type of anaesthesia, postoperative pain, medications and comorbidities.⁸ However, the specific risk of POUR in patients with fragile hip fractures has not been widely investigated. Studies have been conducted to actively explore the factors influencing POUR in older patients with hip fractures and to take targeted measures to reduce the occurrence of POUR; however, there is a large degree of heterogeneity between the results of different studies. A scoping review could be a better choice than a systematic review for quickly describing the research progress in a certain field; showing the scope, depth, breadth and deficiency; and providing more information for the future.⁹ Therefore, we aimed to synthesise the available evidence on the risk factors for POUR among older adults after hip fracture surgery within a scoping review framework.

Scoping review research questions

The review seeks to answer the following questions:

1. What literature is available on POUR incidence and risk factors among older patients with hip fractures (≥60 years)?

2. What are the incidence and known risk factors of POUR internationally for older patients with hip fractures?

Methods

This review was conducted in accordance with the Joanna Briggs Institute methodology for scoping reviews¹⁰ and reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for scoping review (PRISMA-ScR).¹¹ See online supplemental file S1 for the completed PRISMA-ScR checklist. This review was registered in Open Science Framework (https://osf.io/3gpza/).

Search strategy

PubMed, Cochrane Library, CINAHL, Web of Science, Chinese National Knowledge Infrastructure, Wanfang Data and Sinomed databases were searched to identify suitable studies from the start date of the database to the date of the search (1 September 2024). To ensure full coverage of the literature, we performed additional screening of the reference lists for relevant reviews and eligible studies to discover any research articles not identified in the database searches. The detailed search strategy is provided in online supplemental file S2. No limitations on country or language were applied during the search.

Eligibility criteria

We included observational studies reporting on POUR prevalence and risk factors among patients aged 60 years and older with hip fractures. POUR was defined as the inability to effectively empty the bladder by spontaneous voiding within 6 hours after surgery when the bladder urine volume is greater than 300 mL or the ability to effectively empty the bladder by spontaneous voiding with a residual urine volume greater than 100 mL. Identification of POUR was based on either: (1) clinical assessment (palpation/percussion of bladder, patient-reported symptoms) or (2) ultrasound measurement of post-void residual volume (>100 mL). We excluded systematic and non-systematic reviews, conference proceedings, editorials, commentaries, qualitative studies and case studies. Duplicated articles and articles unable to access the full text were also excluded. We also excluded studies with populations with pathologic fractures, multiple fractures, treated for periprosthetic fracture or if studies were published in a language other than English and Chinese.

Study selection

All studies were exported to the EndNote Citation Manager for deduplication. After duplicate removal and training of all reviewers, two reviewers (DZ and YH) independently screened titles and abstracts to identify eligible studies, which were consecutively assessed for eligibility by reading the full text. Consistency checks were performed before each screening phase. First, two reviewers independently screened the titles and abstracts of the retrieved citations to identify potentially eligible publications. Full-text documents were obtained and independently evaluated by two reviewers applying a full set of inclusion and exclusion criteria. Disagreements were resolved by consensus with a third reviewer (JX).

Data extraction and analysis

The extracted information included author, country, year of publication, country (setting), study type (design), sample size and outcomes (prevalence and risk factors). The accuracy of the extraction was verified by a reviewer (SW). No meta-analyses were included in this review. The extracted data were exported to Microsoft Excel (Microsoft 365 version), analysed and presented using descriptive statistics.

Results

Study selection

We identified 106 studies from electronic databases after duplicates were removed. We excluded 28 articles based on title and abstract screening. We excluded a further 66 studies after full-text screening for the following reasons: patient population (n=26), outcome (n=16), study design (n=18), unavailability of full text (n=4) and conference abstract (n=2). Twelve studies (all from published literature) detailing the prevalence and risk factors of POUR were included (figure 1).

Figure 1. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) chart for study selection.

Study characteristics

This review was based on 12 observational studies with a combined total of 2660 participants. The study citations and key characteristics are shown in table 1.12,23 These studies were conducted in China (n=1), Japan (n=3), Israel (n=2), Canada (n=1), France (n=1), Spain (n=1), Korea (n=1), Thailand (n=1) and Sweden (n=1). The publication dates ranged from 2010 to 2024. Twelve studies reported the prevalence of POUR in older patients with hip fractures, ranging from 11.1% to 51.33%. Nine studies reported risk factors for POUR, including activities of daily living (ADL), duration of indwelling catheterisation, faecal impaction, gender, cognitive impairment, use of medication, serological indicators and complications.

Table 1. Included studies and key characteristics (n=12).

No	Author/year	Country	Sample size		Prevalence (%)	Risk factors
			POUR	Non-POUR
1	Tantigate et al 202412	Thailand	22	123	15.2	Use of anti-cholinergic medications, international prostate symptom score ≥8, inability to independently get out of bed within 24 hours postoperatively
2	Higashikawa et al 202213	Japan	24	145	14.2	Activities of daily living
3	Thomas et al 202114	Canada	98	485	16.81	Indwelling catheters for more than 24 hours after surgery, postoperative incontinence
4	Teng et al 202115	France	63	193	24.61	Faecal impaction
5	López-Torres et al 202016	Spain	18	51	26.09	None
6	Kwak et al 201917	Korea	68	146	31.78	The indwelling period of the urethral catheter, male gender
7	Higashikawa et al 201918	Japan	34	187	15.38	Cognitive impairment, activities of daily living
8	Cialic et al 201719	Israel	33	55	37.5	Use of opioid medications, use of anticholinergic medications, level of thyroid-stimulating hormone (TSH), level of albumin
9	Chen 201720	China	28	128	17.95	None
10	Adunsky et al 201521	Israel	328	311	51.33	Diabetes, urinary infection, delirium
11	Tobu et al 201422	Japan	8	64	11.11	The indwelling period of the urethral catheter, preoperative dementia and/or delirium
12	Johansson et al 201023	Sweden	18	30	37.5	None

POUR, postoperative urinary retention.

Prevalence of postoperative urinary retention (POUR) in older patients with hip fractures

The prevalence of POUR in older patients with hip fractures was reported in 12 studies and ranged between 11.1–51.33%, with a total of 742/2660 cases (see table 1). The incidence varies across countries, regions and populations.

Risk factors of postoperative urinary retention (POUR) in older patients with hip fractures

Gender

All the studies explore the influence of demographic factors such as age, sex and body mass index (BMI) on the completion of POUR in older patients with hip fractures. Only one study reported that male patients were found to have an increased risk of POUR (OR, 2.22; 95% CI 1.17 to 4.22).¹⁷ In summary, most studies reported no association between demographic factors (age, sex and BMI) and POUR in older patients with hip fractures.

Impaired activities of daily living and cognitive impairment

Two studies^{13 18} reported that impaired ADL was significantly associated with the development of POUR in older patients with hip fractures. Three studies^{18 21 22} identified three cognitive function-related risk factors associated with POUR in older patients with hip fractures. These included cognitive impairment (OR 4.11, 95% CI 1.53 to 11.03),¹⁸ delirium (OR 1.66, 95% CI 1.09 to 2.52)^{21 22} and preoperative dementia (OR 10.4, 95% CI 1.21 to 89.2).²² However, cognitive impairment has also been reported to be not associated with POUR in older patients with hip fractures.¹³ No association between cognitive state as measured by the mini-mental state examination and POUR has been reported in older patients after hip fractures.^{19 21}

Medication use

In total, two studies^{12 19} reported that opioid use (relative risk (RR) =8) and treatment with anticholinergic medications (RR=1.3) were associated with POUR in older patients with hip fractures. However, opioid use^{12 21} and treatment with anticholinergic medications²² were also reported not to be associated with POUR in older patients with hip fractures. No association between the type of patient-controlled analgesia (intravenous or epidural),¹⁷ duration of patient-controlled analgesia,¹⁷ use of psychotropics²¹ and POUR has been reported in older patients with hip fractures.

Serological indicator

Only one study¹⁹ reported that serum albumin (RR, 0.9) and thyroid-stimulating hormone (RR, 0.6) levels were associated with POUR in older patients with hip fractures. However, serum albumin levels^{13 18 19} have also been reported to be not associated with POUR in older patients with hip fractures. No association between POUR and serum cortisol, haemoglobin, folic acid, free T4 and vitamin B12 levels^{12 17} was reported in older patients with hip fractures.

Complications

In total, three studies^{12 14 21} reported that diabetes (OR 1.55, 95% CI 1.04 to 2.31), urinary infection (OR 3.25, 95% CI 2.16 to 4.90), prostatic hyperplasia (international prostate symptom score ≥8) (OR 9.3) and postoperative incontinence (OR 1.942, 95% CI 1.093 to 3.452) were associated with POUR in older patients with hip fractures. However, diabetes,^{13 18 22} a history of benign prostatic hyperplasia¹⁴ and urinary infection^{12 14} have also been reported to be not associated with POUR in older patients with hip fractures. No associations between POUR and hypertension,^{18 22} overactive bladder,²² circulatory disease,¹⁸ respiratory disease,¹⁸ kidney disease,^{14 18} neurological disease,²² history of bladder or prostate cancer,¹⁴ history of bone fracture¹⁸ or history of osteoporosis¹⁸ were reported in older patients with hip fractures.

Others

Three studies^{14 17 22} reported that the indwelling period of the urethral catheter was associated with POUR in older patients with hip fractures. One study¹⁵ reported that faecal impaction was associated with POUR in older patients with hip fractures. One study¹² reported that the inability to get out of bed within 24 hours postoperatively was associated with POUR in older patients with hip fractures.

Discussion

The International Continence Society defines acute POUR as ‘a painful, palpable or percussable bladder, when the patient is unable to pass any urine’ and chronic POUR as ‘he persistent inability to empty the bladder despite maintaining an ability to urinate’.²⁴ The American Urological Association (AUA) recommends that urinary retention be defined as a post-void residual urine volume (PVR) >300 mL measured on two separate occasions.²⁵ As a key element, significant PVR does not have a worldwide, evidence-based definition. PVR varies widely across different guidelines and populations. Due to the lack of diagnostic criteria for POUR in older patients with hip fractures, the different thresholds set for PVR between the different studies included in this scoping analysis, and the possible population heterogeneity between different countries and regions, there is a large difference in the incidence of POUR reported by each study; however, it also reflects the higher risk of POUR in older patients with hip fractures. This diagnostic heterogeneity underscores the imperative for establishing an evidence-based, population-specific PVR threshold for geriatric hip fracture patients, as current variations in reported POUR incidence not only reflect methodological disparities but also fundamental uncertainties in defining clinically significant retention in this vulnerable cohort. Furthermore, implementation of standardised screening protocols should integrate both quantitative (eg, systematic bladder scanning within 6 hours after surgery) and qualitative (eg, BRUMS assessment for high-risk patients) measures to enable risk stratification, thereby facilitating individualised management pathways.

The occurrence of POUR in older patients with hip fractures is affected by a variety of factors such as low ADL scores, use of anticholinergics, decreased serum albumin and TSH (thyroid-stimulating hormone) levels, the comorbidities of urinary tract infections, prolonged indwelling urinary catheters and faecal impaction. In addition, male gender, cognitive impairment, opioid use and coexisting diabetes may also be risk factors for POUR, which still needs to be further clarified. Although prostatic hyperplasia is prevalent in older men and is a common risk factor for POUR, several studies have reported that there is no direct association between sex and the occurrence of POUR; therefore, the correlation between demographic factors, such as sex and age, and the occurrence of POUR needs to be further explored. Immobility due to hip fracture may exacerbate bladder dysfunction by limiting patients’ ability to assume normal voiding postures or access toileting facilities promptly. Additionally, ADL impairment often correlates with generalised muscle weakness, including detrusor muscle inefficiency, further increasing POUR risk. Cognitive impairment (eg, dementia or delirium) complicates POUR management by reducing patients' awareness of bladder fullness or ability to communicate needs. Neurogenic bladder dysfunction, common in conditions like Alzheimer’s disease, may also contribute. Furthermore, cognitive decline is frequently linked to polypharmacy (eg, anti-cholinergics or sedatives), which independently raises POUR risk.

Few studies have investigated the relationship between thyroid function and POUR in older patients with hip fractures. Only Cialic et al¹⁹ reported that lower levels of thyroid-stimulating hormone were associated with POUR in older patients with hip fractures; further analysis revealed that when POUR was defined based on a PVR of 400 mL, free T4 levels increased and thyroid-stimulating hormone levels decreased. However, contrasting results were observed in older women on admission to the internal medicine department by Justo et al,²⁶ where hypothyroidism was associated with asymptomatic urinary retention, and a direct correlation was found between serum TSH levels and post-void urine residual. Justo et al suggested that hypothyroidism may be related to an atonic bladder or faecal impaction, which impairs bladder emptying. Therefore, the relationship between thyroid function and POUR should be clarified in future studies.

Urinary tract infections exhibit a bidirectional relationship with POUR, wherein each condition may serve as both a precipitating factor and a consequential outcome. The pathophysiological mechanisms underlying this association involve multiple pathways: infection-mediated inflammatory responses can induce bladder outlet obstruction through mucosal oedema, while concurrently exacerbating detrusor muscle hypotonia. Conversely, urinary retention establishes a favourable environment for bacterial proliferation due to urinary stasis, thereby elevating urinary tract infection susceptibility. In geriatric hip fracture populations, urinary tract infections present particular diagnostic challenges due to their frequent manifestation with atypical symptoms (eg, acute delirium or cognitive impairment rather than conventional lower urinary tract symptoms). This clinical presentation may lead to delayed recognition of both urinary tract infections and POUR, potentially worsening outcomes. Current evidence supports the implementation of prophylactic strategies, including restrictive urinary catheterisation protocols and early postoperative mobilisation, to disrupt this pathophysiological cycle and mitigate associated complications.

The use of opioids and anticholinergic drugs can also increase the risk of POUR. Opioids are known to increase the risk of urinary retention through several mechanisms, which decrease the sensation of bladder fullness by partially inhibiting the parasympathetic innervation of the bladder and increasing bladder sphincter tone due to excessive sympathetic stimulation, resulting in bladder outlet restraint and increased resistance to urine flow.²⁷ Anti-cholinergic activity decreases bladder detrusor muscle contractility, leading to POUR. Medications with anticholinergic properties are widely used among older adults. Many commonly used drugs, such as anti-spasmodics, bronchodilators, anti-arrhythmics, anti-histamines, anti-hypertensive drugs, anti-parkinsonian agents, skeletal muscle relaxants and psychotropic drugs, have been demonstrated to have anti-cholinergic activity. Older adults often have multiple diseases and are usually treated with different types of drugs, increasing the probability and severity of urinary retention.²⁸

Strengths and limitations of the review

This is the first scoping review to report and synthesise the risk factors of POUR after hip fracture surgery in older adults, reported in line with the recommendation of the PRISMA-ScR statement, which follows the same rigours and transparent methodology used in systematic reviews. We searched multiple databases for relevant evidence on risk factors of POUR, with study selection completed in duplicate.

This review had some limitations. First, the studies identified through electronic databases were published in English and Chinese, which may have led to publication bias. Second, in keeping with the scoping review framework (which aims to identify and map the scope of available evidence rather than the quality of evidence identified), we did not assess the quality of the included studies. Therefore, it is not possible to determine whether the uncertainty identified for some risk factors reflects varying methodological qualities among the studies. Furthermore, while anaesthetic technique (particularly spinal anaesthesia) is clinically recognised as a potential risk factor for POUR, none of the included studies provided comparative data on this variable. Future research should specifically examine the differential impacts of spinal vs general anaesthesia on POUR incidence in elderly hip fracture populations.

Conclusion

This scoping review explored the incidence and risk factors of POUR among older patients with hip fractures across many countries. Sixteen factors were identified from the 12 articles included in this review. Most risk factors were reported in a single study, limiting the inferences that can be drawn. Identifying risk factors is important, as it will enable healthcare providers to improve POUR for patients after hip fracture surgery through quality improvement and intervention studies. Future studies should identify the risk factors of POUR in older patients with hip fractures and explore the best prevention and management practices for POUR.

Data availability statement

No data are available.