The Effect of Osteoporosis Medication on Risk Attenuation of Non-Trauma Fracture Among Adults with Cerebral Palsy: A Propensity Score-Matched Observational Study

PURPOSE: The efficacy of osteoporosis medication on reducing the risk of non-trauma fracture (NTFx) among adults with cerebral palsy (CP) has not been comprehensively investigated. There are many logistical and biological factors that may reduce this efficacy, and therefore requires attention. The purpose of this propensity score-matched, observational cohort study was to determine if osteoporosis medication was associated with NTFx risk attenuation among adults with CP and compared to adults without CP. MATERIALS AND METHODS: Data from 07/01/2011 to 09/30/2015 were extracted from Optum Clinformatics(®) Data Mart. Claims identified adults (≥18 years), CP, osteoporosis medication, pre-index NTFx (6-months), and post-index NTFx (12-months). CP without osteoporosis medication (CP(Meds-)) and without CP with Meds (non-CP(Meds+); reflects “background” population) served as controls and were matched (6:1 ratio) to adults with CP with Meds (CP(Meds+); n=306). The Meds groups were further stratified by the initiation of their medication as new users or consistent users. Changes in the prevalence of NTFx from pre- to post-index periods were examined with risk ratios (RR) and the change was compared among groups using the ratio of the RR (RRR) via difference-in-difference analysis. RESULTS: New users with CP had: a larger risk attenuation of any NTFx compared to CP(Meds-) (RRR=0.39; 95% CI=0.22–0.71), which was consistent for vertebral column/hip and lower extremities; a larger risk attenuation for NTFx of the lower extremities compared to consistent users with CP (RRR=0.22; 95% CI=0.05–0.93); and a similar risk attenuation of any NTFx compared to new users without CP (RRR=0.81; 95% CI=0.45–1.43), which was consistent for vertebral column/hip and lower extremities. CONCLUSION: The findings suggest that osteoporosis medication is associated with clinically meaningful risk attenuation of NTFx, especially for new users with CP.