OBJECTIVES : This study aims to compare the downstream costs and healthcare utilization associated with using low-dose computed tomography (LDCT) for lung cancer screening in patients with and without Alzheimer’s disease and related dementias (ADRD).

METHODS : Based on data from IBM® MarketScan® Commercial Claims Databases (2014-2018), we have identified four study cohorts: 1) ADRD patients went through LDCT screening, 2) ADRD patients without LDCT screening, 3) non-ADRD population went through LDCT screening, and 4) non-ADRD population without LDCT screening. Healthcare utilization and cost were grouped into outpatient, inpatient, and pharmacy, and summarized using an annual window. We used difference-in-differences (DID) models to estimate the downstream healthcare utilization and cost associated with LDCT screening in both ADRD and non-ADRD population. We used a difference-in-difference-in-differences (DDD) model to explore if LDCT screening was associated with higher downstream cost and healthcare utilization in ADRD population than non-ADRD population.

RESULTS : Compared to individuals without LDCT screening, LDCT screening was associated with increased outpatient visits (2.1, 95% CI: 0.7,3.4) and outpatient cost ($2301.0, 95% CI: 296.2, 4305.8) in the ADRD population and increased outpatient visits (0.6, 95% CI: 0.1, 1.1) in the non-ADRD population within one year after screening. Compared with the non-ADRD population, LDCT screening was found to be associated with an additional 1.5 (95% CI: 0.2, 2.8) outpatient visits, 0.7 (95% CI: 0.1, 1.3) days of inpatient stays, and $4,960.4 (95% CI: 532.7, 9388.0) in overall healthcare costs within 1-year after LDCT in the ADRD population (all p<0.5).

CONCLUSIONS : The downstream cost and healthcare utilization associated with LDCT screening was found to be higher in the ADRD population than normal population.