Geographic Variation in the Utilization of Pacemaker Technology

The goal of this study was to identify differences in percapit rates of single and dual-chamber pacemaker implantation and rates of implantation for given conduction disorder at the county level in the State of California. Significant geographic variation has been documented in the use of coronary angiography and coronary artery bypass surgery. We used large database, the Californi Discharge Database, during the years 1984-1992 to identify the diagnostic codes of patients at risk (complete heart block, Mobitz II block, sinoatrial dysfunction, and other heart block) for single or dual-chambered pacemaker in the twelve most populous counties. Rates were calculated by identifying patients from given county who received pacemaker and dividing by the county population in age groups ‘65-80’ and ‘over 80’, while controlling for given diagnostic code. These aged groups captured 79% of all implants (N = 2827 in 1984). Implantation rates per diagnosis were also calculated for given county. There was variability in implantation rates among large counties in Californi with greater than 100 pacemaker implants in 1984 and 1985. The overall (ventricular + atrioventricular) rate, by county, was significantly different in the population groups ‘65-80’ (p < 0.005) and ‘over 80’ (p < 0.0005). If atrial pacemakers were included in the analysis, the differences in rates persisted; ‘65-80’ (p < 0.005) and ‘over 80’ (p < 0.002). For dual chamber implants only there also was significant variability in both the 65-80 and >80 aged groups (p < 0.0001) among counties. There also was significant variability in the ratio of dual to single-chamber pacemakers by county in both age groups (p < 0.0005). Conclusion: Initial dat using comprehensive database has identified geographic variability in county rates of pacemaker implantation independent of diagnosis. This geographic variation in utilization may represent physician uncertainty in the use of pacemaker technology.