Provider billing margin and cancer treatment selection: population based cohort study

To estimate the association between the billing (profit) margin and clinical benefit of cancer treatments and use by oncologists.

Retrospective population based cohort study SETTING: Population based sample using fee-for-service Medicare claims data.

Medicare beneficiaries with an incident cancer diagnosis from 2015 to 2020; included all patients with cancer treatment indications for which the available treatment options varied in clinical benefit and billing margin.

The primary outcome was the cancer treatment each patient received among treatment options recommended by the National Comprehensive Cancer Network (NCCN). The characteristics of interest were provider billing margin (defined at the patient treatment level, using Medicare reimbursement rates corresponding to the patient's diagnosis date) and a proxy measure of clinical benefit (rank order of treatments based on Evidence Blocks scores developed by the NCCN, corresponding to the patient's diagnosis date). The association between treatment received, billing margin, and clinical benefit was modeled using a conditional logit model with inverse probability-of-treatment weights applied at the patient treatment level to control for patient and provider characteristics.

Twelve cancer indications were examined comprising 19 397 individual patients. Provider billing margin ranged from $0 to $12 692 (£9440; €10 800) for each course of treatment. No association was found between a $100 increase in provider billing margin and the likelihood of treatment use (odds ratio 0.97, 95% confidence interval 0.91 to 1.03). Higher clinical benefit was associated with greater treatment use (1.62, 1.15 to 2.29).

In this observational study of Medicare beneficiaries, selection of cancer treatments was associated with the treatment's clinical benefit but not billing margin. Therefore, it is unlikely that policy and price changes that affect the billing margin of cancer treatments would shift patterns of use.