Background: The transition from Functional Independence Measure (FIM) to Section GG in 2019 disrupted continuity in outcome measurement. Understanding long-term trends and predictors of functional gain (FG) across eras is essential for equitable evidence-based rehabilitation. Methods: We identified acute ischemic stroke (AIS) patients admitted for post-acute care in a multicenter rehab network (2002–2025). FG was defined as discharge minus admission scores for FIM-Motor (Jan 2002 – Sept 2019), Section GG (Oct 2019 – Aug 2025), and FIM-Cognitive (2002–2025). Robust multivariable linear regression with Huber’s M-estimator, to account for non-normal distribution, was used to assess temporal trends and predictors of FG. Regression coefficients (β) and 95% CIs are reported. Results: We included 13,116 AIS discharges (mean age 66.9±14.0 years; 46.3% female; 45.0% Non-Hispanic White NHW). In the FIM era (n=8,647), mean functional motor gain (FMG) was 18.4±11.1 points, rising over time (adjusted β, 95% CI: 0.27/year, 0.19–0.34). Non-Medicare vs. Medicare Fee-for-service insurance (2.47, 1.77–3.18) and greater therapy duration (0.11/hour, 0.09–0.14) predicted greater FMG. Non-Hispanic Black (NHB) vs. NHW patients (–0.94, –1.53 to –0.35), older individuals (–0.04, –0.08 to –0.01), and those with pressure ulcers (–4.75, –6.23 to –3.26) had lower FMG. In the GG era (n=4,469), average FMG rose from 16.0 to 18.9 (β, CI: 0.58/year, 0.36–0.80). Higher admission GG score (0.24, 0.19–0.29), and longer therapy duration (0.45, 0.42–0.48) predicted greater FMG, while NHB (–0.95, –1.83 to –0.06) and Asian (vs. NHW) (–2.31, –4.43 to –0.18) and those with pressure ulcers (–2.56, –3.76 to –1.35) had lower FMG. The mean FIM cognitive gain was 4.7±7.2 points, declining modestly over time (–0.03/year, –0.05 to –0.01). Predictors of greater gains included female sex (0.20, 0.07–0.34), non-Medicare insurance (0.62, 0.42–0.82), and therapy duration (0.024/hour, 0.018–0.03). Conversely, higher admission cognitive score (–0.16, –0.17 to –0.15), older age (–0.01, –0.02 to –0.001), pressure ulcers (–0.60, –0.91 to –0.28), and minority race/ethnicity were associated with lower cognitive gain. Conclusions: Functional motor gain during inpatient rehabilitation rose steadily across both FIM and GG eras, with consistent modifiable drivers (therapy intensity, ulcer management) and persistent disparities by race and insurance. Policies to ensure equitable access to quality rehabilitation are warranted.
Bako et al. (Thu,) studied this question.