Interstate Variability of Rates of Percutaneous Transluminal Coronary Angioplasty in the United States Medicare Population

Percutaneous Transluminal Coronary Angioplasty (PTCA) procedures are commonly performed in the United States (US) for the invasive management of coronary artery disease (CAD). Because of the relative expense and frequency of PTC and increasingly elderly US population, the annual health care expenditure for PTC is significant and will continue to expand. The clinical indications for PTC have been fairly well-established. Our study tested the hypothesis that the incidence of PTC per State was constant. We examined the 1992 PTC database from the Health Care Financing Administration (HCFA) which included procedure volume for 805 US hospitals performing PTC on Medicare patients and was aggregated by State. Population dat for age >65 was obtained for each State from the US Census Bureau for 1990. We found significant variability in PTC rates per 100,000 population age >65 (PTCA/100,000) ranging from 89 to 831. For the 10 States with the largest population age >65, the PTCA/100,000 ranged from 130 to 503. As the number of programs (per 100,000 age >65) increased, the PTCA/100,000 increased (r2 = 0.40; P < 0.0001) (A). This was also observed for the 10 largest States and was highly significant (r2 = 0.71; P = 0.002) (B). Low rates of PTCA/100,000 were associated with Certificate of Need programs. We conclude that: 1) PTCA/100,000 varies considerably from State to State despite established indications, 2) Certificate of Need programs may reduce PTCA/100,000 rates, and 3) investigation into the appropriateness of PTC should be performed on an individual statewide basis.