Variations in the use of cardiac procedures in the Veterans Health Administration

Background Considerable variability exists in the use of cardiac procedures for patients with heart disease. One cause for this variability is the ava ilability of local facilities to perform these procedures. This study was i nitiated to identify health system features that are related to rates of ca theterization, percutaneous coronary angioplasty, and coronary artery bypas s graft surgery in the Veterans Affairs health care system in which structu red referral systems are intended to compensate for variation in local reso urce availability Methods Medical records of 30,901 patients admitted to a Veterans Affairs m edical center with coronary artery disease were analyzed. Odds ratios (OR) and 95% confidence intervals (CI) for undergoing each procedure, based on c linical variables (age, sex, race, coronary artery disease type, and a comp uted comorbidity score), and local Veterans Affairs facility features (geog raphic region, primary service area size, and hospital complexity) were est imated by logistic regression. Results Regression models demonstrated significant associations between the odds of undergoing each procedure and medical center geographic and comple xity features, after adjustment for clinical variables. Associations includ ed the presence of a cardiac catheterization laboratory For undergoing cath eterization (OR 1.86, CI 1.76 to 1.95) and the presence of a cardiac surgic al program for angioplasty (OR 1.46, CI 1.36 to 1.57) and bypass grafting ( OR 1.43, CI 1.34 to 1.53). Including health system variables in addition to clinical variables in the regression models improved the discriminating ab ility of the models by 44.2% to 51.4%. Conclusions Geographic location and the complexity of the local Veterans Af fairs hospital are important determinants of the use of cardiac procedures in the Veterans Affairs health care system, even though referral networks a re intended to correct for local differences in hospital complexity.