OBJECTIVES: Despite recommendations to receive treatment within 30 days of a colon cancer (CC) diagnosis, many patients diagnosed with CC do not initiate treatment within 30 days. The delay can be traced to patient- or contextual factors however the implications for healthcare costs are not well understood. The aim of this study is to quantify differences in healthcare costs associated with treatment delay.

METHODS: This study utilized the Surveillance, Epidemiology, and End Results (SEER)-Medicare 5% Cancer File, which represents a linkage between cancer registry and Medicare claims. We included patients diagnosed with CC between 2016 and 2018, aged 65 years and older, initiated treatment within 6 months post-diagnosis, and were continuously enrolled in a Medicare fee-for-service health plan for 12 months following treatment initiation. Comparison groups were defined based on the time between diagnosis and treatment initiation: 1) no delay (ND; ≤30 days post-diagnosis); 2) delay (1-6 months post-diagnosis). We calculated total, inpatient, outpatient, and out-of-pocket (OOP) costs based on the 12 months following treatment initiation. Regression models adjusted for age, race, census region, and residence in a medically underserved Census tract. We reported cost ratios using two-stage generalized linear models (GLM) for inpatient and OOP costs and single-stage GLM for total and outpatient costs.

RESULTS: A total of 1,166 patients were included in the analysis. Of this, 509 (43.7%) experienced delay and 657 (56.3%) experienced ND. There were no statistically significant differences between the delay and ND groups for total, inpatient, and OOP costs. The delay group had statistically significantly higher mean outpatient costs compared to the ND group (1.33, p-value <0.01).

CONCLUSIONS: Delayed CC treatment was associated with higher outpatient costs with no difference in total costs. Additional research is needed to better characterize healthcare utilization patterns associated with higher outpatient costs.