Polypharmacy Among Privately Insured Adults with Cerebral Palsy: A Retrospective Cohort Study

BACKGROUND: Adults with cerebral palsy (CP) have increased risk for developing various secondary chronic diseases, especially when they have other neurodevelopmental disabilities (NDDs). Multiple medications are likely prescribed to manage the greater morbidity-related burden for adults with CP; however, because health care delivery and care coordination is suboptimal for this population, adults with CP may have an increased risk for polypharmacy. To date, very little is known about the prescribing practices and extent of polypharmacy for adults with CP. OBJECTIVE: To determine the prevalence and adjusted odds of polypharmacy among adults with CP only and those with CP+NDDs, compared with adults without CP. METHODS: Data from 2017 Optum Clinformatics Data Mart, a U.S. private administrative database, was used for this retrospective cohort study. Diagnosis codes were used to identify adults (aged ≥ 18 years) with CP, NDDs (e.g., intellectual disabilities, epilepsy, and autism spectrum disorders), and 24 relevant morbidities. Polypharmacy was examined as 0-4 versus ≥ 5, 0-9 versus ≥ 10, and 0-14 versus ≥ 15 medications. Logistic regression estimated the OR and 95% CI of polypharmacy before and after adjusting for age, sex, region of residence, and multimorbidity (as 0, 1, 2, 3, 4-5, and ≥ 6 morbidities). Exploratory analyses were conducted to compare polypharmacy among young (18-40 years) and middle-aged (41-64 years) adults with CP only and CP + NDDs with elderly (≥ 65 years) adults without CP. RESULTS: Adults with CP only (n = 5,603) and CP + NDDs (n = 2,474) had higher unadjusted prevalence and adjusted OR for each polypharmacy definition compared with adults without CP (n = 9.0 million; e.g., ≥ 5 medications: adjusted OR for CP only = 1.38, 95% CI = 1.30-1.47; CP + NDDs: OR = 2.42, 95% CI = 2.20-2.67). Adults with CP+NDDs had higher unadjusted prevalence and adjusted OR of each polypharmacy definition compared with CP only. Compared with elderly without CP, the unadjusted prevalence of polypharmacy was lower for young adults with CP only (e.g., ≥ 5 medications: 60.2%, 43.8%), similar for young adults with CP+NDDs (e.g., ≥ 15 medications: 10.9%, 12.5%), and elevated for middle-aged CP only and CP + NDDs (e.g., ≥ 10 medications: 28.7%, 34.3%, 41.7%). CONCLUSIONS: Privately insured adults with CP only and CP + NDDs have an elevated prevalence of polypharmacy compared with adults without CP, even after accounting for multimorbidity. Importantly, adults aged 18-40 years with CP have a similar (CP + NDDs) prevalence of polypharmacy compared with the general geriatric population, with the prevalence increasing further for CP by middle age.