Impact of insurance type and timing of Medicaid enrollment on survival among adolescents and young adults with cancer

Background: Adolescents and young adults (AYAs) with public or no insurance experience later stage at diagnosis and worse overall survival compared with those with private insurance. However, prior studies have not distinguished the survival impact of continuous Medicaid coverage prior to diagnosis compared with gaining Medicaid coverage at diagnosis. Methods: We linked a cohort of AYAs aged 15-39 who were diagnosed with 13 common cancers from 2005 to 2014 in the California Cancer Registry with California Medicaid enrollment files to ascertain Medicaid enrollment, with other insurance determined from registry data. We used Cox proportional hazards regression to evaluate the impact of insurance on survival, adjusting for clinical and demographic characteristics. Results: Among 62 218 AYAs, over 65% had private/military insurance, 10% received Medicaid at diagnosis, 13.2% had continuous Medicaid, 4.1% had discontinuous Medicaid, 1.7% had other public insurance, 3% were uninsured, and 2.6% had unknown insurance. Compared with those with private/military insurance, individuals with Medicaid insurance had significantly worse survival regardless of when coverage began (received Medicaid at diagnosis: hazard ratio [95% confidence interval]: 1.51 [1.42-1.61]; continuously Medicaid insured: 1.42 [1.33-1.52]; discontinuous Medicaid: 1.64 [1.49, 1.80]). Analyses of those with Medicaid insurance only demonstrated slightly worse cancer-specific survival among those with discontinuous Medicaid or enrollment at diagnosis compared with those with continuous enrollment, but results were not significant stratified by cancer site. Conclusions and relevance: AYAs with Medicaid insurance experience worse cancer-specific survival compared with those with private/military insurance, yet continuous enrollment demonstrates slight survival improvements, providing potential opportunities for future policy intervention.