Scale, nature, preventability and causes of adverse events in hospitalised older patients.

OBJECTIVE to gain insight into the scale, nature, preventability and causes of adverse events in hospitalised older patients. DESIGN a three-stage retrospective, structured, medical record review study of 7,917 records of patients admitted in 21 Dutch hospitals in 2004. MAIN OUTCOME MEASURES incidence, preventability, clinical process category, consequences and causes of adverse events in hospitalised patients of 65 years and older, compared with patients younger than 65. RESULTS adverse events and preventable adverse events occur significantly more often in older patients [6.9% (95% CI: 5.9-8.0%) and 2.9% (95% CI: 2.3-3.7%), respectively] than in younger patients [4.8% (95% CI: 4.0-5.7%) and 1.8% (95% CI: 1.3-2.4%), respectively]. In older patients, the adverse events were more often related to medication (20.1 versus 9.6%) (P < 0.01). An exploration of the causes revealed that the inability to apply existing knowledge to a new and complex situation contributes more often to the occurrence of adverse events in older patients than in younger patients (36.4 versus 24.3%) (P < 0.05). CONCLUSION to reduce the number of adverse events in older patients in the future, more particular training of hospital staff in geriatric medicine is required, with a specific focus on medication.