Assessing the Risk for Falls in Older Adults After Initiating Gabapentin Versus Duloxetine.

Abstract

The evidence informing the harms of gabapentin use are at risk of bias from comparing users with nonusers. To describe the risk for fall-related outcomes in older adults starting treatment with gabapentin versus duloxetine. New user, active comparator study using a target trial emulation framework. MarketScan (IBM) commercial claims between January 2014 and December 2021. Adults aged 65 years or older with diabetic neuropathy, postherpetic neuralgia, or fibromyalgia and without depression, anxiety, seizures, or cancer in the 365 days before cohort entry. New initiation of treatment with gabapentin or duloxetine (comparator). The primary outcome was the hazard of experiencing any fall-related visit in the 6 months after initiating gabapentin or duloxetine until discontinuation of treatment. Secondary outcomes were hazard of severe fall-related events defined as a fall associated with hip fracture or emergency department visit or hospitalization associated with a fall. Stabilized inverse probability of treatment weighting was used to adjust for baseline characteristics. Our analytic cohort included 57 086 older adults with a diagnosis of interest initiating treatment with gabapentin (<i>n</i> = 52 152) or duloxetine (<i>n</i> = 4934). Overall median follow-up duration was 30 days (IQR, 30 to 90 days). Weighted cumulative incidence of a fall-related visit per 1000 person-years at 30, 90, and 180 days was 103.60, 90.44, and 84.44 for gabapentin users and 203.43, 177.73, and 158.21 for duloxetine users, respectively. At 6-month follow-up, incident gabapentin users had lower hazard of falls (hazard ratio, 0.52 [95% CI, 0.43 to 0.64]), but there was no difference in the hazards of experiencing severe falls. Results were similar across sensitivity and subgroup analyses. Claims may contain fewer frail adults and undercount falls. Compared with incident use of duloxetine, incident use of gabapentin was not associated with increased fall-related visits. None.