(Research Hub Theater) Longitudinal Patterns of Post-fracture Outpatient Physical/Occupational Therapy Use and Its Association with 3-year Mortality Among Adults with Cerebral Palsy

Background and/or Objectives: To characterize physical and/or occupational therapy (PT/OT) use patterns within 6 months post-fracture among adults with cerebral palsy (CP) and determine if these patterns were associated with mortality up to 3 years post-fracture.

Design: Retrospective cohort study

Setting: Random 20% Medicare fee-for-service dataset

Participants: Adults ≥18 years old with CP who sustained an incident fragility fracture between 01/01/2014-12/31/2016

Interventions: PT/OT use was defined as binary (yes/no) at weekly intervals from the date of fracture to 6 months post-fracture

Main Outcome Measures: First, PT/OT use patterns, from the date of fracture to 6 months post-fracture, were identified using group-based trajectory modeling. Second, Cox regression was used to assess the association between trajectory groups and mortality up to 3 years post-fracture as hazard ratios (HR, with 95% confidence intervals [CI]) before and after adjusting for age, sex, fracture site, co-occurring neurological conditions, and a modified version of the Whitney Comorbidity Index (mWCI, a CP-specific multi-morbidity index). Effect modification was tested by each covariate.

Results: Of 2,429, the majority (73.2%) had little-to-no probability of PT/OT use, while 16.0% and 10.7% had early (weeks 0-2) and later (weeks 5-8) initiation, respectively. Compared to the little-to-no PT/OT group, the 3-year adjusted mortality rate was 26% lower for the early initiation group (HR=0.74; 95% CI=0.55-1.00; p=0.049) and 20% lower for the late initiation group (HR=0.80; 95% CI=0.57-1.12). There was effect modification by the mWCI (P < 0.001). After stratifying by mWCI median and interquartile range, the adjusted mortality rate was lower for early and late initiation groups (HR range, 0.37 to 0.71), but the effect was stronger for lower (HR=0.37-0.45) than higher (HR=0.70-0.71) mWCI values.

Conclusions: Most adults with CP may be underutilizing outpatient PT/OT services within 6 months post-fracture. Early or late initiation of PT/OT use was associated with improved survival compared to little-to-no PT/OT use, though the effect was stronger among those with less medical complexity.