The Association Between Sex and Lung Cancer Screening Adherence to Follow-Up in a Cohort of Veterans

Introduction: The 2021 update to the United States Preventive Services Task Force guidelines for lung cancer screening (LCS) aims to reduce disparities derived from sex, race/ethnicity, and socioeconomic status. Few studies have addressed adherence to LCS among female Veterans. Methods: To evaluate differences in adherence to LCS by sex, we conducted a retrospective cohort study within the VA Connecticut LCS Program between June 2013 and March 2020. Our primary outcome was nonadherence, defined as lack of completion of a chest CT scan within the guideline recommended interval plus a 90-day grace period. Eligible patients were enrolled in the screening program and had a baseline Lung-RADS score of 1, 2, or 3. Patients with Lung-Reporting and Data System (RADS) 4 were excluded due to variability in follow-up recommendations. We adjusted for age, race, smoking history, mental/medical comorbidities, and primary care (PC) visits (1-year after first/index CT). Logistic regression modeling was used to determine associations between sex and nonadherence overall and stratified by Lung-RADS 1-2 and Lung-RADS 3. Results: Among 4,711 Veterans, the overall rate of nonadherence was 34%. Female Veterans were 66% more likely nonadherent to follow-up (odds ratio [OR] = 1.66, confidence interval [CI] = 1.19-2.30) compared with male Veterans. Substance use disorder was associated with greater nonadherence (OR = 1.22, CI = 1.01-1.47). Lower nonadherence was observed among patients with COPD (OR = 0.77, CI = 0.66-0.9) and PC engagement (OR for nonadherence with 5 or more PC visits = 0.78, CI = 0.67-0.91). The associations between sex and nonadherence were similar in models stratified by Lung-RADS groups 1-2, although did not reach significance for the Lung-RADS 3 group. Discussion: In this cohort, female Veterans were more likely nonadherent. More work is needed to understand the distinct barriers to LCS follow-up among female Veterans. Health care system engagement significantly reduced nonadherence, which may partially explain higher rates of nonadherence among female Veterans who had fewer medical comorbidities.