Adverse events among nursing home residents with Alzheimer's disease and psychosis.

PURPOSE: The objective of this study was to quantify rates of adverse events in a high-risk multi-morbid population of institutionalized patients with Alzheimer's disease (AD).

METHODS

We conducted a retrospective cohort study among nursing home residents diagnosed with AD and psychosis during January 1998 to October 1999. Using the Medicare Minimum Data Set (MDS) and Medicare inpatient claims (ICD-9 codes), 7728 nursing home residents aged 55-95 years with AD and psychosis were identified for study. Potential adverse events of interest were identified from the MDS and Medicare inpatient claims (ICD-9 codes). We estimated the incidence rate (IR) and 95% confidence interval (CI) for each adverse event during a 2-year follow-up period.

RESULTS

Of the 7728 residents studied, nearly 30% were considered 'dependent' by the activities of daily living (ADL) score and approximately 15% exhibited severe cognitive impairment at baseline. At least 90% had comorbid psychiatric disorders. The most common adverse event was accidental injury, occurring at a rate of 97.7 per 100 person-years (95%CI = 94.7-100.7). Other common adverse events were death (IR = 44.6/100 person-years; 95%CI = 42.9-46.4), infection (IR = 41.8/100 person-years; 95%CI = 39.7-43.8), pain (IR = 43.5/100 person-years; 95%CI = 41.2-45.9), anorexia (41.3/100 person-years; 95%CI = 39.1-43.6), and weight change (IR = 40.2/100 person-years; 95%CI = 38.7-41.7).

CONCLUSIONS

This information on the occurrence of adverse outcomes among nursing home patients with AD and psychosis provides useful context for any safety event observed among patients treated for psychosis.