Geographic Variation of Gabapentinoids and Opioids in US Nursing Homes.

OBJECTIVES: To examine and quantify geographic variation in gabapentinoids, opioids, and their concurrent use among long-stay nursing home residents in the United States. DESIGN: Cross-sectional study. SETTING AND PARTICIPANTS: A total of 232,484 long-stay residents aged ≥65 years in 9741 US nursing homes across 300 hospital referral regions (HRRs) in 2021. METHODS: We used Minimum Data Set 3.0 linked to Medicare Parts A and D claims, facility characteristics, and HRR data. Outcomes were gabapentinoid-only use, opioid-only use, and concurrent use. Residents were classified by nursing home state and HRR. Cross-classified multilevel logistic regression models quantified between-HRR and between-state variation. Sequential models estimated the proportional change in variance after adjustment for resident, facility, and HRR characteristics. RESULTS: The prevalence of gabapentinoid-only use was 13.4%, opioid-only use was 9.1%, and concurrent use was 5.4%. Geographic variation was substantial, particularly for opioid-only and concurrent use. For opioid-only use, resident characteristics explained 39.1% of HRR-level and 35.3% of state-level variation, with 61.2% and 60.8% explained in fully adjusted models. For concurrent use, resident characteristics explained most variation, accounting for 64.3% of HRR-level and 52.1% of state-level variation, with 65.4% and 62.2% explained after full adjustment. In contrast, gabapentinoid-only use showed smaller geographic variation, with facility characteristics explaining more HRR-level variance than resident factors. CONCLUSIONS AND IMPLICATIONS: Geographic variation exists in gabapentinoids, opioids, and their concurrent use in US nursing homes. Variation in opioid-only and concurrent use largely reflects resident characteristics, whereas gabapentinoid use appears more influenced by facility and regional factors, suggesting differences in prescribing practices beyond clinical need.