Time-driven activity-based costing of multivessel coronary artery bypass grafting across national boundaries to identify improvement opportunities: study protocol.

INTRODUCTION: Coronary artery bypass graft (CABG) surgery is a well-established, commonly performed treatment for coronary artery disease--a disease that affects over 10% of US adults and is a major cause of morbidity and mortality. In 2005, the mean cost for a CABG procedure among Medicare beneficiaries in the USA was $32, 201 ± $23,059. The same operation reportedly costs less than $2000 to produce in India. The goals of the proposed study are to (1) identify the difference in the costs incurred to perform CABG surgery by three Joint Commission accredited hospitals with reputations for high quality and efficiency and (2) characterise the opportunity to reduce the cost of performing CABG surgery.

METHODS AND ANALYSIS: We use time-driven activity-based costing (TDABC) to quantify the hospitals' costs of producing elective, multivessel CABG. TDABC estimates the costs of a given clinical service by combining information about the process of patient care delivery (specifically, the time and quantity of labour and non-labour resources utilised to perform each activity) with the unit cost of each resource used to provide the care. Resource utilisation was estimated by constructing CABG process maps for each site based on observation of care and staff interviews. Unit costs were calculated as a capacity cost rate, measured as a $/min, for each resource consumed in CABG production. Multiplying together the unit costs and resource quantities and summing across all resources used will produce the average cost of CABG production at each site. We will conclude by conducting a variance analysis of labour costs to reveal opportunities to bend the cost curve for CABG production in the USA.

ETHICS AND DISSEMINATION: All our methods were exempted from review by the Stanford Institutional Review Board. Results will be published in peer-reviewed journals and presented at scientific meetings.