The presence of moderate extrapyramidal signs predicts poorer outcomes in a community‐based cohort of multi‐ethnic demented elders

Abstract

AbstractBackgroundExtrapyramidal signs (EPS) are a common feature of Alzheimer's Disease (AD) associated with worse outcomes in observational studies of dementia. Prior studies have been primarily conducted in predominately white, clinic‐based samples. Less is known regarding the role of EPS in the disease course of dementia in ethnic minority and non‐clinic‐based populations.MethodPredictors 3 (P3) is a multi‐ethnic community‐based cohort study of dementia. Recruitment began in 2011 and is ongoing. Participants are evaluated annually by trained investigators. 142 P3 participants with a baseline diagnosis of probable dementia were selected for this study. Moderate EPS was defined as a score of 2 or more on selected items from the Unified Parkinson's Disease Rating Scale. The cognitive endpoint was defined as a score of <= 10 on the Folstein MMSE, the functional endpoint as a score of >= 10 on the 17‐point Blessed Dementia Rating Scale, and the institutional equivalent endpoint as need for equivalent to nursing home care. Adjusted Cox models were fitted for time to death and cognitive, functional, and institutional equivalent endpoints with baseline moderate EPS as predictor. Effect modification was assessed by fitting cross‐product terms for moderate EPS by ethnicity, sex, age, education, and APOE polymorphism.ResultMean follow‐up time was 3.61 years (range: 0.29 ‐ 7.50, SD = 1.95). 33 participants (23.2%) had moderate EPS at baseline. 53 died (37.3%), 23 (17.2%) reached the cognitive endpoint, 45 (36.3%) the functional endpoint, and 44 (37.9%) the institutional equivalent endpoint post‐baseline. Moderate EPS at baseline was significantly associated with an increased hazard of death (HR = 2.57, 95% CI = 1.30, 5.10) and of reaching the functional endpoint (5.59, 95% CI = 2.36, 13.27). Associations between moderate EPS and the cognitive and institutional equivalent endpoints were not statistically significant. No evidence was found for effect modification of associations on either additive or multiplicative scales.ConclusionIn a multi‐ethnic community‐dwelling cohort of demented elders, we found that baseline moderate EPS significantly predicted time to death and time to functional endpoint, but not time to cognitive and institutional equivalent care endpoints. These findings confirm those of previous studies conducted on predominately white, clinic‐based samples.