Emergency medical readmission: long-term trends and impact on mortality.

There is increasing emphasis on prevention of emergency medical readmissions. The broad pattern of acute medical readmissions was studied over a seven-year period and the impact of any readmission on 30-day mortality was recorded. Significant predictors of outcome, including co-morbidity and illness severity score, were entered into a multivariate regression model, adjusting the univariate estimates of the readmission status on mortality. In total, 23,114 consecutive acute medical patients were admitted between 2002-8; the overall readmission rate was 27%. Readmission independently predicted an increased 30-day mortality; the odds ratio, was 1.12 (95% confidence interval (CI) 1.09 to 1.14). This fell to 1.05 (95% CI 1.02 to 1.08) when adjusted for outcome predictors including acute illness severity. The trend for readmissions was to progressively increase over time; the median times between consecutive admissions formed an exponential time series. Efforts to reduce or avoid readmissions may depend on an ability to modify the underlying chronic disease.