The mortality burden of non-trauma fracture for adults with cerebral palsy

BACKGROUND: Individuals with cerebral palsy (CP) manifest skeletal fragility problems early in life, are vulnerable to non-trauma fracture (NTFx), and have a high burden of premature mortality. No studies have examined the contribution of NTFx to mortality among adults with CP. The purpose of this study was to determine if NTFx is a risk factor for mortality among adults with CP and if NTFx exacerbates mortality risk compared to adults without CP. METHODS: Data from 2011 to 2016 Optum Clinformatics® Data Mart and a random 20% sample Medicare fee-for-service were used for this retrospective cohort study. Diagnosis codes were used to identify adults (18+ years) with and without CP, NTFx, and pre-NTFx comorbidities. Crude mortality rates per 100 person years were estimated. Cox regression estimated hazard ratios (HR and 95% confidence interval [CI]) for mortality, comparing: (1) CP and NTFx (CP + NTFx; n = 1777); (2) CP without NTFx (CP w/o NTFx; n = 12,933); (3) without CP and with NTFx (w/o CP + NTFx; n = 433,560); and (4) without CP and without NTFx (w/o CP w/o NTFx; n = 6.8 M) after adjusting for demographics and pre-NTFx comorbidities. RESULTS: The 3-, 6-, and 12-month crude mortality rates were highest among CP + NTFx (12-month mortality rate = 6.80), followed by w/o CP + NTFx (12-month mortality rate = 4.91), CP w/o NTFx (12-month mortality rate = 2.15), and w/o CP w/o NTFx (12-month mortality rate = 0.49). After adjustments, the mortality rate was elevated for CP + NTFx for all time points compared to CP w/o NTFx (e.g., 12-month HR = 1.61; 95%CI = 1.29–2.01), w/o CP + NTFx (e.g., 12-month HR = 1.49; 95%CI = 1.24–1.80), and w/o CP w/o NTFx (e.g., 12-month HR = 5.33; 95%CI = 4.42–6.44). There were site-specific effects (vertebral column, lower extremities) on 12-month mortality. CONCLUSIONS: NTFx is associated with an increase of 12-month mortality risk among adults with CP and compared to adults without CP. Findings suggest that NTFx may be a robust risk factor for mortality among adults with CP.