The effects of methylphenidate on stress fractures in patients' ages 10-29: a national database study

Objectives: Current literature is divided on the effect of methylphenidate (MP) on stress fracture development and if this medication increases fracture, or is actually protective for it. This study further investigates this effect utilizing a large national database. We hypothesized that individuals on MP would have a reduced risk of SF compared against controls. Methods: This study utilized the Humana insurance data set within the PearlDiver Patient Records Database (PearlDiver Inc, Fort Wayne, Indiana). All patients' ages 10-29 were included and patients were identified without ADHD, with ADHD not on MP, and with ADHD on MP. ADHD and stress fracture diagnoses were identified by International Classification of Disease, Tenth Revision codes. Bivariate analysis of stress fracture occurrence was conducted using chi-square analysis. Multivariate logistic regression was used to calculate odds ratios, controlling for age, sex, race, and Charlson Comorbidity Index (CCI). Statistical analysis was performed using the PearlDiver software, which runs R, Version 1.1.442. An α value of .05 was set as the level of significance. Results: The study included 29,590 patients on MP and 831,439 patients not on MP from ages 10-29. The highest proportions of patients who filled MP prescriptions were in the age range 10 to 14 years old (51.2%), followed by 15 to 19 (41.0%). Patients rarely continue MP from years 20 to 24 (16.5%) or 25 to 29 (9.6%). ADHD patients on MP had the lowest calculated risk of stress fractures (0.45%) compared to patients without ADHD (0.54%) and ADHD patients not on methylphenidate (0.58%). In all three patient groups, most stress fractures occurred in 15 to 19-year olds. Patients with ADHD on MP conferred lower odds of stress fracture than ADHD patients not on MP and patients without ADHD (aOR = 0.64, p = 0.0002). The older age groups 20-24 and 25-29 involved less risk of stress fracture compared to the youngest age group 10-14 (p < 0.0001; p < 0.0001), as well as did male gender (p < 0.0001). Conclusions: This database-based study of the effect of MP on SF adds to the growing body of literature providing evidence that MP may offer protective benefit for stress fracture.