Predictable Value of Functional Independence Measure Differs between Anterior and Posterior Circulation Ischemic Strokes

Abstract

Background: The functional independence measure (FIM) is a standard tool to provide a detailed evaluation of ADL of patients with disabilities. This study aimed to show the differences in FIM scores as an outcome predictor between patients with anterior circulation (AC) and posterior circulation (PC) strokes. Methods: Consecutive patients with acute ischemic stroke hospitalized within 7 days after onset were investigated. Baseline NIHSS scores, 1st-FIM (< 72 h after ­admission to stroke unit), 2nd-FIM (< 72 h before discharge), and modified Rankin Scale (mRS) scores were collected. Logistic regression analyses were used to identify predictors of a favorable outcome (mRS 0–2) at 3-month after stroke. Results: Three hundred eighty-five patients (median age, 78 years; male, 59%; median length of stroke unit stay, 20 days) were included. The median baseline NIHSS, 1st- and 2nd-FIM scores were 4 (interquartile range 2–9), 65 (33–91), and 98 (54–122) respectively. Baseline NIHSS (3 vs. 4, p = 0.01) and mRS score at 3-month (1 vs. 2, p = 0.01) were lower, and 1st-FIM (75 vs. 64, p < 0.01) and 2nd-FIM (113 vs. 95, p = 0.01) were higher in 82 patients with PC than 303 patients with AC strokes. On multivariate logistic regression analysis, 2nd-FIM score was an independent predictor of favorable outcomes in both PC (OR 1.18, 95% CI 1.04–1.48, p < 0.01) and AC (OR 1.12, 95% CI 1.06–1.20, p < 0.01) strokes. The optimal cutoff scores of 2nd-FIM for predicting favorable outcome were 104 for PC (sensitivity 0.82, specificity 0.88) and 93 for AC (0.88–0.90) strokes. Conclusions: The differences in outcome predictability by FIM score between AC and PC strokes should be considered, although FIM scores at discharge from stroke unit were useful to predict a favorable outcome.