Cost analysis of coronary artery bypass grafting surgery under single-payer reimbursement in Taiwan

In the aging world, coronary artery disease is the leading cardiovascular disease burden. Coronary artery bypass surgery grafting (CABG) entails high medical costs. Identifying the driving factors of medical cost variability is essential for health policies and the enhancement of quality of care. We conducted this study using data from the National Health Insurance Research Database (NHIRD) in the Longitudinal Health Insurance Database 2005, which includes 1 million randomly selected individuals from the 2005 registry of beneficiaries for their medical records collected between January 2000 and December 2013. We analyzed the in-hospital and one-year follow-up medical costs of patients with isolated CABG. Multiple linear regression models were developed to identify the effects of patient characteristics, comorbidities, and hospital-related factors on the surgical costs and the total one-year medical costs after discharge. Female patients had significantly higher surgical costs and higher one-year medical costs after discharge. Hospital volume, surgeon’s age, surgeon’s operation volume and the number of anastomosis vessels affected CABG outcomes considerably. Both the surgeon’s age and volume negatively affected the one-year medical costs after discharge. Charlson comorbidity index (CCI), recent one-year medical costs before surgery, emergency surgery and extracorporeal membrane oxygenation (ECMO) use were correlated with higher one-year medical costs after discharge. Using multiple linear regression models could explain part of the variances for the one-year medical costs after discharge using fewer factors. We found that surgical cost and recent one-year medical costs before CABG were the most crucial predicting factors for the one-year medical costs after discharge. Cost analysis about the variations of in-hospital and recent oneyear costs before CABG is essential information for determining health policy and further improving clinical quality.