Abstract TMP45: Association of Late Functional Improvement With 5-Year Post-stroke Outcomes: A Population-based Cohort Study

Abstract

Background: We recently demonstrated that late functional improvement between 3-12 months post-stroke occurs in about one in four patients with ischaemic stroke, more commonly in lacunar strokes. It is unknown whether this late improvement is associated with better long-term clinical or health economic outcomes. Methods: In 1-year ischaemic stroke survivors of the Oxford Vascular Study (OXVASC; 2002-2014), we examined changes in functional status (modified Rankin Scale[mRS], Rivermead Mobility Index[RMI], Barthel Index[BI]) from 3-12 months post-stroke. We used Cox regressions adjusted for age, sex, 3-month disability, and stroke subtype (lacunar vs non-lacunar) to examine the association of late functional improvement (by ≥1 mRS grades, ≥1 RMI points, and/or ≥2 BI points between 3-12 months) with 5-year mortality and institutionalization (admission to nursing or residential care home). We used similarly adjusted generalized linear models to examine the association with 5-year health/social-care costs. Analyses were restricted to patients capable of showing improvement per the relevant scale (mRS>0, RMI<15, BI<20). Results: Among 1,288 1-year survivors, 1,135 had 3-month mRS>0, of whom 319 (28.1%) demonstrated late functional improvement between 3-12 months post-stroke. 1-year survivors who demonstrated late functional improvement between 3-12 months per the mRS had lower 5-year mortality (aHR 0.68, 95%CI 0.51-0.91, p=0.009), were less likely to be institutionalized at 5-years (aHR 0.48, 0.33-0.72, p<0.001), and incurred lower 5-year health/social-care costs (margin -$17,524, -24,763 to -10,284, p<0.001). These associations remained on excluding patients with recurrent strokes during follow-up (e.g. for 5-year mortality: aHR 0.69, 0.49-0.96, p=0.026) and on examining late functional improvement per the RMI and/or BI (e.g. for 5-year mortality with RMI: aHR 0.64, 0.46-0.87, p=0.004). Conclusions: Late functional improvement post-stroke is associated with lower 5-year mortality, institutionalization rates, and health/social-care costs. These findings should motivate patients and clinicians to maximize late recovery in routine practice, and consider access to rehabilitative services for at least 1-year post-stroke.