The mortality burden of non-trauma fracture for adults with cerebral palsy
Daniel G. Whitney, Sarah Bell, Edward A. Hurvitz, Mark D. Peterson, Michelle S. Caird, Karl J. Jepsen
Abstract
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. 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. 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. 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.