Resource use trajectories for aged medicare beneficiaries with complex coronary conditions

To use coronary revascularization choice to illustrate the application of a method simulating a treatment's effect on subsequent resource use.

Medicare inpatient and outpatient claims from 2002 to 2008 for patients receiving multivessel revascularization for symptomatic coronary disease in 2003-2004.

This retrospective cohort study of 102,877 beneficiaries assessed survival, days in institutional settings, and Medicare payments for up to 6 years following receipt of percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG).

A three-part estimator designed to provide robust estimates of a treatment's effect in the setting of mortality and censored follow-up was used. The estimator decomposes the treatment effect into effects attributable to survival differences versus treatment-related intensity of resource use.

After adjustment, on average CABG recipients survived 23 days longer, spent an 11 additional days in institutional settings, and had cumulative Medicare payments that were $12,834 higher than PCI recipients. The majority of the differences in institutional days and payments were due to intensity rather than survival effects.

In this example, the survival benefit from CABG was modest and the resource implications were substantial, although further adjustments for treatment selection are needed.