Central nervous system–active medication polypharmacy among rural and urban veterans with fibromyalgia, migraine, or irritable bowel syndrome

PURPOSE: This study examined whether rural veterans with multisymptom chronic pain presentations, including those diagnosed with fibromyalgia, migraine, and/or irritable bowel syndrome (IBS), were at heightened risk for polypharmacy with central nervous system (CNS)-active medications, a potentially risky prescribing practice. METHODS: Administrative data were used to identify veterans receiving care for fibromyalgia, migraine, or IBS during 2022. Negative binomial regression models, conducted separately for fibromyalgia, migraine, and IBS, examined the impact of rural residence and rural site of care on number of concurrent CNS medications. Models were then adjusted for demographics and medical and psychiatric comorbidities. RESULTS: A total of 250,533 veterans were treated for fibromyalgia (n = 30,462), migraine (n = 188,640), and/or IBS (n = 49,169) in the Veterans Health Administration in 2022. Rates of polypharmacy were 16.2% for those with fibromyalgia, 13.5% for those with migraine, and 8.2% for those with IBS. In fibromyalgia, rural veterans' mean number of concurrent CNS-active medications was 2.59 (SD, 1.92), compared to 2.63 (SD, 1.90) for urban veterans; in migraine, the mean (SD) number of concurrent medications was 2.43 (1.87) in rural veterans, compared to 2.40 (1.83) in urban veterans; and in IBS, the mean (SD) number of concurrent medications was 1.75 (1.75) in rural veterans, compared to 1.79 (1.75) in urban veterans. In adjusted analyses, minimal differences were found between rural and urban-dwelling veterans in the risk of an increased number of concurrent CNS medications (adjusted incident rate ratios [aIRRs] ranged from 1.01 to 1.03) and between those receiving primary care from rural clinics versus medical centers (aIRRs ranged from 0.95 to 0.97). CONCLUSION: These findings do not support the hypothesis that rural veterans are at increased risk for CNS polypharmacy.