Abstract
IMPORTANCE: The increased use of gabapentinoids has been most pronounced in older people who are also susceptible to hip fractures. OBJECTIVE: To investigate the overall association between gabapentinoids and the risk of hip fractures and the stratified association across age groups, frailty status, and history of chronic kidney disease. DESIGN, SETTING, AND PARTICIPANTS: This was a case-case-time-control study in patients hospitalized for hip fracture in Victoria, Australia, between March 1, 2013, and June 30, 2018, with at least 1 prescription for a gabapentinoid before fracture. Conditional logistic regression was used to estimate the odds ratio (OR) and 95% CI for gabapentinoid dispensing in the index (1-60 days prefracture) compared with the reference (121-180 days prefracture) period. To adjust for the underlying time trend in gabapentinoid use, each index case was matched with up to 5 controls, selected from future cases of the same age and sex. Subgroup analyses were conducted in subgroups with or without chronic kidney disease (CKD), frailty scores less than 5, and frailty scores 5 and above. Frailty was computed using the Hospital Frailty Risk Score (HFRS). Data were analyzed from November 2023 to April 2024. EXPOSURE: Gabapentinoids (pregabalin or gabapentin). MAIN OUTCOME AND MEASURE: Hip fracture. RESULTS: Of 28 293 patients hospitalized for hip fractures, 2946 (1752 [59.5%] aged ≥80 years; 2099 [71.2%] female) were dispensed a gabapentinoid before hip fracture. Gabapentinoid dispensing was associated with increased odds of hip fractures (OR, 1.96; 95% CI, 1.66-2.32). After adjusting for the exposure-time trend and concomitant use of other central nervous system medications, the odds of hip fractures remained elevated (OR, 1.30; 95% CI, 1.07-1.57). The association between gabapentinoid dispensing and hip fracture was higher in patients with HFRS 5 and above (OR, 1.75; 95% CI, 1.31-2.33) and CKD (OR, 2.41; 95% CI, 1.65-3.52). CONCLUSIONS AND RELEVANCE: In this case-case-time-control study of Australian residents hospitalized for hip fracture, gabapentinoid use was associated with an increased risk of hip fractures, especially in patients who were frail or had chronic kidney disease. In addition to the known risk associated with kidney impairment, frailty status may be an important risk factor when considering use of gabapentinoids.