Incidence, preventability and consequences of adverse events in older people: results of a retrospective case-note review.

OBJECTIVES to estimate the extent, preventability and consequences of adverse clinical events in elderly and non-elderly patients. DESIGN a two-stage structured, retrospective, patient case-note review. SETTING a large NHS hospital in England. POPULATION a random sample of 1,006 non-psychiatric patients. MAIN OUTCOME MEASURES proportion of patients with adverse events, the proportion of preventable adverse events and the types and consequences of adverse events in patients >or=75 and under 75 years old. RESULTS forty five [13.5%; 95% confidence interval (CI) 10-17] of 332 patients >or=75 years and 42 (6.2%; 95% CI 4-8) of 674 patients <75 years had at least one adverse event. There was a significantly raised risk of experiencing an adverse event with increasing age [odds ratio (OR) = 1.03 adverse events per year of life, P < 0.001]. There was no statistically significant difference in preventability of adverse events and also in experiencing disability or death as a result of an adverse event by age after adjustment for potential confounders. CONCLUSION adverse events are significantly more common in non-psychiatric elderly inpatients than younger patients. There is little evidence that adverse events in older patients are more preventable and lead to disability or death more frequently.