Health Insurance Continuity Is Associated with Stage at Diagnosis Among Children, Adolescents, and Young Adults Newly Diagnosed with Lymphoma
Authors: Zhang Xinyue , Castellino Sharon M. , Yabroff K. Robin , Stock Wendy , Bai Shasha , Mertens Ann C. , Lipscomb Joseph , Ji Xu 
Published: December 2023

Background: Many uninsured patients do not gain Medicaid coverage until the point of, or after, their cancer diagnosis, which can limit access to early cancer detection and delay diagnosis and treatment, leading to poorer survival outcomes. Our previous research found that gaining Medicaid at, or after, diagnosis (vs. continuous Medicaid coverage) is significantly associated with inferior survival among children and adolescents/young adults (AYAs) with lymphoma, a leading cause of pediatric and AYA cancers. However, whether this relationship is mediated by lymphoma stage at diagnosis is unknown. To fill this knowledge gap, the current study examines the association between Medicaid coverage continuity and disease stage among this vulnerable population.

Methods: We identified 13,655 children and AYAs (ages 0-39 years) newly diagnosed with lymphoma between 2007-2012, using the linked Surveillance, Epidemiology, and End Results (SEER) registries and Medicaid enrollment data. To measure coverage continuity, we categorized patients into those with 1) continuous Medicaid (enrolled in Medicaid for ≥12 months prior to and through diagnosis), 2) newly gained Medicaid (enrolled in the month of or within 12 months after diagnosis), 3) other patterns of noncontinuous Medicaid, 4) private insurance at diagnosis, 5) other insurance types at diagnosis (Medicare, TRICARE, Military, VA, or Indian/Public Health Service), and 6) unknown or no insurance at diagnosis. The last 3 groups comprised patients not linked to Medicaid enrollment data; thus their insurance continuity patterns were unknown, and their insurance status at the time of diagnosis was extracted from SEER registries.

The association between coverage continuity and late-stage diagnosis was examined with separate multivariable logistic regression models among all patients and by cancer subtypes (Hodgkin lymphoma, non-Hodgkin lymphoma). Late-stage was defined as stage IV (vs. stage I-III) using the Ann-Arbor staging classification. Regressions also adjusted for sex, race/ethnicity, age at diagnosis, diagnosis year, rurality, neighborhood socioeconomic status (SES), and state of residence.

Results: Half of our sample had private insurance (50.3%), followed by Medicaid insurance (26.9%), other insurance type (10.3%), and unknown (7.9%) or no insurance (4.7%). Among Medicaid-insured patients, 40.1% had newly gained Medicaid, followed by continuous Medicaid (32.5%) and other patterns of noncontinuous Medicaid (27.3%). Overall, one-fourth (24.8%) of the sample had stage IV lymphoma (Figure 1).

Compared with privately insured patients, the adjusted percentage of stage IV diagnoses was 16.8 percentage points (ppt; 95% CI=14.6-19.0, p&lt;0.001), 10.6 ppt (95% CI=8.2-13.0, p&lt;0.001), and 4.9 ppt (95% CI=2.7-7.1, p&lt;0.001) higher in patients with newly gained Medicaid, other patterns of noncontinuous Medicaid, and continuous Medicaid, respectively. Among the subset of Medicaid-insured patients, the adjusted percentage of stage IV diagnoses was 10.7 ppt (95% CI=7.5-13.8, p&lt;0.001) and 5.4 ppt (95% CI=3.1-7.6, p&lt;0.001) higher among patients with newly gained Medicaid and other patterns of noncontinuous Medicaid, respectively, compared to those with continuous Medicaid. These patterns persisted across lymphoma subtypes.

Notably, coverage continuity patterns varied by sociodemographic factors, with non-Hispanic Black (vs. non-Hispanic White) patients, AYAs ages 15-39 years (vs. pediatric patients ages ≤14), and residents of non-metropolitan (vs. metropolitan) areas or lower SES neighborhoods significantly more likely to have newly gained Medicaid.

Conclusions: Less than one-third of Medicaid-insured children and AYAs with lymphoma had continuous insurance coverage prior to cancer diagnosis. Lacking continuous Medicaid coverage was significantly associated with advanced-stage lymphoma diagnosis.