Background: Many older adults lose functional ability during the course of acute illness and fail to recover function. We sought to determine whether performance on a cognitive screen at the time of hospital admission predicted the magnitude of functional recovery after hospitalization.
Methods: We studied 2557 patients from two teaching hospitals to examine the association between level of impaired performance on a cognitive status screen and maintenance and recovery of functioning from admission through 90 days after discharge. On admission, 14% had mildly impaired cognitive performance with three or four errors on the Short Portable Mental Status Questionnaire; 28% had moderate to severely impaired cognitive performance with five or more errors on the cognitive status screen or inability to complete the screen and a diagnosis of dementia.
Results: Performance on a brief cognitive screen on admission was strongly related to subsequent change in function. Among patients who needed help performing one or more activities of daily living at the time of admission, 23% of patients with moderate to severely impaired cognitive performance, 49% of patients with mildly impaired cognitive performance, and 67% of patients with little to no impairment in cognitive performance recovered ability to independently execute an additional activity of daily living by discharge (p <.001). Similar relationships were seen for change in instrumental activities of daily living and mobility. In multivariate repeated measures analyses of basic and instrumental activities of daily living and mobility on admission, discharge, and 30 and 90 days after discharge, patients with mildly impaired cognitive performance on admission showed less improvement than patients who did not have impaired cognitive performance, but more than those with moderate to severely impaired cognitive performance. The pattern of results did not change when patients with any signs of delirium were excluded. Patients with impaired cognitive performance were more likely to be admitted to a nursing home for the first time by 90 days after discharge. The odds ratios were 2.8 (95% confidence interval = 1.8-4.5) for patients with mildly impaired cognitive performance and 6.7 (95% confidence interval = 4.5-9.8) for patients with moderate to severely impaired cognitive performance.
Conclusion: Cognitive screening at hospital admission can be used to stratify patients according to the magnitude of expected functional recovery after an acute illness that required hospitalization.