The relationship between physician and hospital PCI volume thresholds and mortality

Objectives: Previous studies have found that physician volume or hospital volume has been associated with outcomes for percutaneous coronary intervention (PCI). The American College of Cardiology, The American Heart Association, and The Society for Cardiovascular Interventions recommend that the minimum annual PCI volumes for physicians and hospitals are 50 and 200 cases, respectively, in order to maintain competency. Few empirical studies have explored whether a relationship exists between physician or hospital PCI volume threshold and patient outcome; therefore, the objective of this study was to determine the relationship between physician and hospital PCI volume thresholds and mortality. Methods: This study used the Taiwan National Health Insurance Research Database. The study subjects were 30,905 patients who underwent PCI in 2009. A restricted cubic spline model was utilized to determine thresholds for the relationship between physician and hospital PCI volume and 30-day mortality. After adjustment for patient, physician, and hospital characteristics, a hierarchical mixed-effect logistic model was used to examine the impact of physician and hospital volume thresholds on 30-day mortality. Results: Once the annual physician volume reached 50 cases, the declining trend in risk-adjusted 30-day mortality rates began to flatten. Moreover, patients treated by physicians with volumes reaching 50 cases had 53.6% lower odds of 30-day mortality compared with those treated by physicians with volumes of fewer than 50 cases. Conclusions: Patients who are treated by physicians who perform 50 PCIs or more a year are at decreased risk for mortality.