A Longitudinal Study Exploring Practice-Makes-Perfect Effect in Taiwan — Using Coronary Artery Bypass Graft as an Example

Presenter: Yu-Chia Chang, Asia University

Abstract

OBJECTIVES: In the past three decades, many “volume-outcome” studies have supported the hypothesis that higher volume was associated with better outcomes. However, most studies were cross-sectional based, thus can only demonstrate the association between volume and outcome, but not the effect of volume on outcome. This study therefore aimed to examine the production efficiency of ways to provide CABG. Specifically, the hypothesis was that practice-makes-perfect by using longitudinal data to examine how the accumulated experience of Coronary Artery Bypass Graft Surgery (CABG) operation done by junior surgeons (those physicians newly started to file the procedure to the Bureau of NHI) may affect patients’ health outcomes.

METHODS: Data were extracted from Taiwan Health Insurance Database from 1997-2005. Study samples were identified from patients received CABGs by junior surgeon between 2000 and June 2005. Major health outcomes included in-hospital mortality rate and mortality rate during the period from admission to 30 days after discharge. Generalized Estimating Equations (GEE) were used to estimate the effect of volume on outcome with adjustment for characteristics of patients, surgeons, and hospitals.

RESULTS: Sixty-eight junior surgeons performed CABGs for 3,063 patients during 2000 to June 2005 in Taiwan. All health outcomes were significantly better among patients receiving CABGs as junior surgeons’ experience accumulated. The accumulation of an additional CABG operation reduced probability of death during hospitalization by 0.4% and probability of death during the period from admission to 30 days after discharge by 0.3%.

CONCLUSIONS: As junior surgeons’ CABGs experience accumulated, patients’ outcomes tend to become better. The finding supports the hypothesis that "practice-makes-perfect" in the case of junior surgeons performing CABGs in Taiwan. In terms of production efficiency, it would be more efficient to designate limited CABG centers to provide services so that surgeons can accumulate their experience and stabilize their quality of care more quickly.