Sex differences in inappropriate prescribing among elderly veterans.

BACKGROUND: Previous studies have suggested that older women may be more likely than older men to receive potentially inappropriate prescriptions. A better understanding of sex differences in inappropriate prescribing can help inform the development of effective interventions.

OBJECTIVE: This study was conducted to assess sex differences in rates of inappropriate prescribing before and after accounting for potentially appropriate indications and to examine sex differences in predictors of inappropriate drug use.

METHODS: This was a retrospective cohort study of administrative data from the national Veterans Health Administration (VA). Participants were veterans aged >or=65 years who had >or=1 patient visit at VA outpatient facilities in fiscal year 1999 (FY99) and 2000 (FY00). The main outcome measure was the diagnosis-adjusted prevalence of 33 potentially inappropriate medications as judged by the Beers criteria in FY00: overall, by individual drug, and in 3 categories grouped by potential indication ("always avoid," "rarely appropriate," and "some indications").

RESULTS: The study population included 965,756 patients (946,641 men and 19,115 women). Women were more likely than men to receive inappropriate medications overall and in all 3 categories, even after accounting for diagnoses that may have justified the prescription. Women were more likely to receive 16 of the 33 medications (analgesics, psychotropic drugs, and anticholinergic agents), and men were more likely to receive 3 of the 33. After controlling for sociodemographic characteristics, number of medications, and care characteristics, women remained more likely to receive inappropriate drugs. Receipt of geriatric care was equally protective for men and women, although only a small proportion received this care. Psychiatric comorbidity was associated with inappropriate prescribing for men but not for women.

CONCLUSIONS: Analgesic, psychotropic, and anticholinergic medications that should be avoided contributed to higher rates of inappropriate drug use among older women than among older men. Targeted efforts to avoid these medications in older women may help reduce overall rates of inappropriate prescribing. Sex-stratified reporting of quality indicators that assess inappropriate prescribing among community-dwelling elders would help monitor the effectiveness of improvement efforts.