ABSTRACT
Objective
To examine the role of insurance coverage of lung cancer screening in driving shifts in lung cancer stage at diagnosis.
Study Setting and Design
We performed difference-in-differences (DID) analyses to compare changes in the proportion of early-stage lung cancer diagnosis between pre-coverage (2007–2014) and post-coverage (2015–2019) periods across insurance groups.
Data Sources and Analytic Sample
Using the National Cancer Institute’s Surveillance, Epidemiology, and End Results database, we identified patients with non-small cell lung cancer aged 55–77 years and diagnosed between 2007 and 2019. Health insurance at diagnosis was categorized as private, Medicare (fee-for-service [FFS], FFS with supplemental private coverage, FFS with Medicaid, and Medicare Advantage with and without Medicaid), Medicaid (FFS and managed care), military health plans, and uninsured.
Principal Findings
Among 227,112 patients, 63,676 (28.04%) had private insurance, 130,770 (57.58%) Medicare, 14,982 (6.60%) Medicaid, 5941 (2.62%) military health insurance, and 11,743 (5.17%) were uninsured. Compared with uninsured patients, a significantly greater increase in the proportion of early-stage lung cancer diagnosis between pre-coverage and post-coverage periods was observed among Medicaid patients (DID = 2.88 percentage points [ppt], 95% CI 0.73–5.02 ppt), but not patients with private insurance, Medicare, or military health insurance. Among Medicaid beneficiaries, those in managed care showed a significantly greater shift compared with those in FFS during 4–5 years post-coverage (DID = 8.22 ppt, 95% CI 4.51–11.93 ppt). Among Medicare FFS beneficiaries, dual enrollment in Medicaid was associated with a significantly smaller increase in the proportion of early-stage diagnosis compared with FFS-only enrollment during 4–5 years post-coverage (DID = −4.40 ppt, 95% CI [−6.40]–[−2.40] ppt).
Conclusions
The results suggest that beneficial stage shifts following the recommendation for lung cancer screening varied by health insurance status and type. Addressing patient, provider, and system-level barriers to lung cancer screening and downstream care is essential to translate lung cancer screening coverage into earlier-stage diagnosis.