Quality of care is associated with survival in vulnerable older patients

Background: Although assessment of the quality of medical care often relies on measures of process of care, the linkage between performance of these process measures during usual clinical care and subsequent patient outcomes is unclear. Objective: To examine the link between the quality of care that patients received and their survival. Design: Observational cohort study. Setting: Two managed care organizations. Patients: Community-dwelling high-risk patients 65 years of age or older who were continuously enrolled in the managed care organizations from 1 July 1998 to 31 July 1999. Measurements: Quality of care received by patients (as measured by a set of quality indicators covering 22 clinical conditions) and their survival over the following 3 years. Results: The 372 vulnerable older patients were eligible for a mean of 21 quality indicators (range, 8 to 54) and received, on average, 53% of the care processes prescribed in quality indicators (range, 27% to 88%). Eighty-six (23%) persons died during the 3-year follow-up. There was a graded positive relationship between quality score and 3-year survival. After adjustment for sex, health status, and health service use, quality score was not associated with mortality for the first 500 days, but a higher quality score was associated with lower mortality after 500 days (hazard ratio, 0.64 [95% Cl, 0.49 to 0.84] for a 10% higher quality score). Limitations: The observational design limits causal inference regarding the effect of quality of care on survival. Conclusions: Better performance on process quality measures is strongly associated with better survival among community-dwelling vulnerable older adults.