Multiple Chronic Conditions and Functional Outcome after Ischemic Stroke: A Systematic Review and Meta-Analysis

BACKGROUND: Multiple chronic conditions (MCC) contribute to functional disability in the general population although its role in predicting functional outcome (FO) among patients with stroke is not well understood. There is no universal agreement on the approach to measuring MCC in stroke, and findings have been mixed regarding MCC being an independent predictor for poststroke FO. OBJECTIVES: This review aims to summarize the findings of studies that have investigated the relationship between MCC and FO after ischemic stroke using a MCC index. METHOD: PubMed and Embase were systematically searched for studies conducted among ischemic stroke patients that have examined the adjusted association between prestroke MCC and FO. The quality of the included studies was appraised using a risk of bias (RoB) assessment checklist. A meta-analysis was performed for the association between MCC and FO using a random effects model to estimate the overall pooled ORs. RESULTS: Twelve of the 18 studies included were hospital-based cohort studies, with a median RoB score of 4.75 points (range 1-9, higher scores for higher RoB). Studies predominantly used the Charlson Comorbidity Index (CCI), or the Modified CCI to measure MCC burden, and the modified Rankin scale to measure FO. Half of the studies reported a significant negative association between MCC and FO, which was also found by the meta-analysis with a pooled OR of 1.11 (95% CI 1.05-1.18). CONCLUSIONS: The current review supports that increased MCC is associated with worse poststroke FO although population-based studies of this association are lacking. Future research should aim to develop more refined measures of MCC that consider the severity and interactions of comorbid conditions reflective of the broader stroke population and to understand the relationship between MCC and poststroke FO with thorough adjustment for confounding factors.