Regional differences in prescribing quality among elder veterans and the impact of rural residence

Abstract

Purpose: Medication safety is a critical concern for older adults. Regional variation in potentially inappropriate prescribing practices may reflect important differences in health care quality. Therefore, the objectives of this study were to characterize prescribing quality variation among older adults across geographic region, and to compare prescribing quality across rural versus urban residence.

Methods: Cross-sectional study of 1,549,824 older adult veterans with regular Veterans Affairs (VA) primary care and medication use during fiscal year 2007. Prescribing quality was measured by 4 indicators of potentially inappropriate prescribing: Zhan criteria drugs to avoid, Fick criteria drugs to avoid, therapeutic duplication, and drug-drug interactions. Frequency differences across region and rural-urban residence were compared using adjusted odds-ratios.

Findings: Significant regional variation was observed for all indicators. Zhan criteria frequencies ranged from 13.2% in the Northeast to 21.2% in the South. Nationally, rural veterans had a significantly increased risk for inappropriate prescribing according to all quality indicators. However, regional analyses revealed this effect was limited to the South and Northeast, whereas rural residence was neutral in the Midwest and protective in the West.

Conclusions: Significant regional variation in prescribing quality was observed among older adult veterans, mirroring recent findings among Medicare beneficiaries. The association between rurality and prescribing quality is heterogeneous, and relying solely on national estimates may yield misleading conclusions. Although we documented important variations in prescribing quality, the underlying factors driving these trends remain unknown, and they are a vital area for future research affecting older adults in both VA and non-VA health systems.