Table 3.

Summary of results of eligible studies of patient factors and rehabilitation outcomes

Author (Year) Study Design	Study Objective	Main Patient Factors	Main Outcome(s)	Covariates	Main findings
Vincent et al. (2010) Retrospective cohort study	Examine the relationship between anemia and rehabilitation outcomes	Anemia: very low hematocrit (<30%), low (30% to women: 0.35, men: 0.36), normal (women: >0.35, men: >0.36) Bilateral: (yes/no)	Functional outcomes at discharge: Functional independence measure (FIM), FIM sub-scores (e.g., walking, stair climbing), FIM efficiency Cost: length of hospital stay, inpatient rehabilitation, pharmacy, therapy costs	Patient factors: Age, sex, joint replacement type (primary or revision)	Functional outcomes: No differences across anemia groups overall or by bilateral status. Costs: Patients with very low hematocrit had longer length of stay and incurred higher total costs than those with normal hematocrit.
Chu et al. (2016) Retrospective cohort study	Describe functional outcomes after bilateral total knee arthroplasty	Sex, age	Functional outcomes at discharge: FIM (relative to admission) FIM efficiency Other outcomes: Readmission to hospital Length of inpatient rehabilitation facility stay	None	Relationship between patient factors (age, sex) and outcomes not shown. FIM improvement: 26.1 ±10.5 (p<0.05) FIM efficiency: 2.33 ±0.84 Re-admitted to hospital: 8.5% Length of stay: 11.7±4.2
Folden et al. (2007) Prospective cohort study	Examine the impact of patient factors on functional recovery after hip repair surgery	Age, sex, Berg Balance Scale, Fatigue Severity Scale, Fall Efficacy Scale, pain,comorbidity, 10 item CES-D, Minimal Mental Status Exam, Functional Life Scale, complications	Functional outcomes 3 months post-discharge: Independent activities of daily living (Functional Life Scale)	All patient factors were included in the model.	32% returned to presurgical functional level by 3 months. Higher balance scores were associated with higher scores on 3-month post-surgical Functional Life (β=0.46, p=<0.001) and higher MMSE scores (β=2.53, p=0.01) were associated with reduced performance.
Tian et al. (2010) Prospective cohort study (Follow-up at 6 months by design, but averaged 8 months given challenges locating and enrolling patients in the follow-up study.)	Examine association between rehabilitation patterns and outcomes for patients with hip arthroplasty	Patterns of rehabilitation care	Primary outcome at ~8 months: Motor FIM Secondary outcome: SF-12 physical component summary (PCS) Additional outcomes: Falls, medical complications, avoidable emergency room visits, rehospitalizations, and quality of life	Demographics (age, sex, race, living status) Elective vs. nonelective Surgery Health/Functional status at admission (pain, motor FIM, Cognitive FIM, days from surgery to admission) Comorbidity/Severity (Comprehensive Severity Index)	90% received rehabilitation from multiple settings, driven by initial care setting, rather than patient factors. Half had home health care after inpatient rehabilitation, 73.1% of non-elective and 83.1% of elective surgeries had home health care after skilled nursing. Patterns of care explained little of the variation in Motor FIM and SF-12 PCS at follow-up. White patients, those with higher Motor FIM, and Cognitive FIM at baseline had higher Motor FIM and SF-12 PCS at follow-up. Those with non-elective surgeries and comorbid conditions had worse Motor FIM and SF-12 PCS scores at follow-up.
Siebens et al. (2012) Prospective cohort study	Examine the association between weight-bearing as tolerated and outcomes of inpatient rehabilitation after hip arthroplasty	Weight-bearing as tolerated or restricted weight-bearing	Primary outcome at discharge: FIM: Total, Motor, Cognitive Home discharge (Yes/No)	Demographics (age, sex, race) Type of surgery Osteoarthritis, osteoporosis Highest pain (scale: 1–10) Complications Comorbidity/Severity (Comprehensive Severity Index)	79.9% were weight-bearing as tolerated No differences were observed between the WBAT and RWB groups in cognitive, motor, and total FIM scores at discharge. The patients who were younger, with lower maximum severity, had better cognition, and were weight-bearing as tolerated had a greater likelihood for home discharge.
Siebens et al. (2016) Prospective cohort study	Examine the association between initial recovery trajectory and functional outcomes at discharge after hip arthroplasty	Initial recovery trajectory (slower, moderate, faster)	Primary outcome at discharge: FIM: Total, Motor, Cognitive Home discharge (Yes/No)	Demographics (age, sex, race) Type of surgery Osteoarthritis, osteoporosis Highest pain (scale: 1–10) Complications Comorbidity/Severity (Comprehensive Severity Index)	From unadjusted models: Total FIM, Motor FIM, and Cognitive FIM at discharge increased with speed of recovery, with the lowest averages in the slower initial recovery group. While all patients in the faster initial recovery group were discharged to home, 82% of the moderate group and 66% of the slower group were discharged to home.
Cogan et al. (2021) Prospective cohort study	Examine the association between therapy minutes per length of stay day, rate of recovery, and functional outcomes after joint replacement	Therapy minutes per length of stay day (low: < 80 minutes, medium: 80 to 130 minutes, high: > 130 minutes per LOS day) Rate of recovery (low, medium, high gain trajectories)	Primary outcome at discharge: FIM Other outcomes: Self-care tasks	Demographics (sex, age, race) Social supports (marital status, living situation) Comorbidity	Therapy minutes per length of stay day were not associated with FIM at discharge. High therapy minutes per length of stay day was associated with self-care at discharge (p=0.03). Participants in medium and high trajectories improved FIM and were able to conduct self-care tasks at discharge.
Kim et al. (2021) Randomized clinical trial	Examine effectiveness of preoperative water exercise in improving outcomes after total knee arthroplasty	Preoperative aquatic exercise Sixty-minute sessions (warm-up (10 minutes), joint range of motion for flexibility and strength (20 minutes), low intensity endurance to improve cardiovascular fitness (20 minutes), and end with a cool down (10 minutes) Three times a week for 4 – 8 weeks	Primary outcome: 30-day National Surgical Quality Improvement Project defined morbidity Secondary outcomes: Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) Mobility Assessment Tool-short form (MAT-sf) Short Physical Performance Battery (SPPB) Geriatric Depression Scale-short form (GDS-sf) Montreal Cognitive Assessment (MoCA) Inflammatory markers (TNF-α, IL-6, hs-CRP)	Demographics (sex, age, race) Body mass index Charlson comorbidity score	Preoperative aquatic exercise was not associated with 30-day National Surgical Quality Improvement Project defined morbidity, and several secondary outcomes (SPPB, MAT-sf, GDS-sf, and all inflammatory markers). Preoperative aquatic exercise was associated with post-surgical improvements in total WOMAC and MoCA scores.