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

Abstract

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.

Shared Physiologic Pathways Among Comorbidities for Adults With Cerebral Palsy

“…This may shed some light on a newly forming concept in the field that bone fragility is implicated in the pathogenesis of unhealthful aging for adults with cerebral palsy. A recent epidemiologic study have found that sustaining a fragility fracture is a robust risk factor for premature mortality for adults with cerebral palsy, even after accounting for demographics, cardiorespiratory diseases, diabetes, cancer, and kidney disease ( 40 ). Additional epidemiologic studies have also found that fragility fractures are a robust risk factor for incidence of several cardiorespiratory diseases for adults with cerebral palsy ( 41 – 44 ).…”

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

“…Adults ≥18 years of age with CP were identified by searching for at least one claim for CP which covered all diagnostic CP types (eg, quadriplegia), as previously described, including codes. 16–19 Data about the severity of CP using common clinical measures (eg, gross motor function classification system) are not available in insurance claims. Further, >70% of the CP sample had “other” or “unspecified” CP.…”

“…Guided by the literature, 32–34 fracture of the vertebral column, hip (including proximal femur), non-proximal femur, tibia/fibula, humerus, ulna/radius, or unspecified location without trauma codes (eg, vehicle accident) 7 days before to 7 days after the index fracture date was defined as NTFx, as previously described, 16–19 and all other fractures were considered trauma fractures. Fractures in the pre-index time period was identified as trauma or non-trauma and by each site.…”

“…Previous work has shown that the age-standardized prevalence of fracture is more than double for women and men with vs without CP, 13 , 14 and that nearly half of adults ≥18 years of age are medically diagnosed with low bone mass. 15 Emerging evidence using nationwide administrative claims data suggests that NTFx is a risk factor for mortality 16 and incidence of cardiovascular 17 , 18 and respiratory 19 diseases among adults with CP, which are among the leading causes of premature mortality for this population. 20 , 21 Further, the relative risk of post-NTFx adverse outcomes was greater for <65 year olds, suggesting an earlier than expected burden of NTFx for adults with CP prior to reaching the elderly years.…”

“…Osteoporosis medications are prescribed to reduce the risk of NTFx and augment skeletal robustness and are associated with a lower risk of mortality, 24 which is important for adults with CP given the premature mortality burden 20 , 25 that may be exacerbated by NTFx. 16–19 Preliminary studies from children with CP have shown the efficacy of bisphosphonates, which are anti-resorption osteoporosis medications, on reducing fracture risk. 26–28 However, these few studies had small sample sizes.…”