Pregabalin and injury: A nested case‐control and case‐crossover study

PURPOSE: This study was performed to investigate the association between the use of pregabalin and injury. METHODS: The study was based on a predefined cohort of patients aged >/=20 years who had been registered for >/=6 months and contributed to the Japan Medical Data Center claims database. All patients (cases) had been treated for injuries from January 2014 to December 2016. One-to-four case-control matching was performed for age, sex, calendar day of injury (index date), and follow-up duration. A conditional logistic regression analysis was performed to calculate the odds ratio (OR) for pregabalin use within 180 days prior to the index date between the matched cases and controls, with adjustment for comorbidities and relevant drug categories associated with a risk of injury. To minimize within-individual confounding, we also performed a case-crossover analysis to compare the odds of pregabalin use between a 30-day hazard period immediately before the injury and five consecutive 30-day control periods within individuals with injury. RESULTS: Among the 2 324 974 people in the nested cohort, we identified 18 084 cases with injury and 71 885 matched controls. The proportion of pregabalin use was 1.7% (304/18 084) and 1.1% (803/71 885), respectively. The adjusted OR for injury was 1.22 (95% confidence interval [CI], 1.06-1.40). In the case-crossover analysis (n = 304), pregabalin use was also significantly associated with an increased risk of injury (adjusted OR, 1.48; 95% CI, 1.10-2.00). CONCLUSION: This large database study using two different study designs consistently suggested that the use of pregabalin may be associated with an increased risk of injury.