Utilization of medications for neuropathic pain in patients with and without knee and hip osteoarthritis in Sweden: A population-based cohort study.

OBJECTIVE: Use of neuropathic pain medications is increasing in OA patients, but it is unclear if this is driven by OA-specific use or presence of comorbidities. We aimed to investigate the use of neuropathic pain medications attributable to knee and hip OA pain. DESIGN: We included all residents aged ≥35 years of the Skåne region, Sweden, in 2018. After exclusions, 645,991 individuals remained, where 81,606 had diagnosed knee and/or hip OA. We compared prevalence of dispensed neuropathic pain medications between those with and without OA using logistic regression (odds ratios approximated risk ratios [RR]), adjusting for comorbidities associated with use of such medications. We interpreted any higher prevalence remaining after adjustment as being compatible with possible OA-related use. Due to interaction effect, males and females were studied separately. RESULTS: Among OA females, crude prevalence of dispensed neuropathic pain medications was highest among 45-54-year-olds (4.0%), with a decreasing prevalence toward 75-84-year-olds (2.3%) compared to 1.5% in non-OA females. After adjusting for comorbidities, the RR for females with vs without OA was 1.4 (95% CI 1.3-1.6) at age 50 and 1.0 (95% CI 0.9-1.1) at age 80. Males had similar prevalence of use across ages, 1.5% in persons with OA and 0.8% in persons without. After adjustment for comorbidities there was no association between OA and neuropathic medication dispensations (RR 1.0; 95% CI 0.9-1.1). CONCLUSION: In particular, middle-aged OA females may use neuropathic pain medications for treatment of OA-related pain, as increased prescribing remained after adjusting for relevant comorbidities.