Variations of physician group profiling indicators for asthma care

To determine how much of the variation in physician group profiling for asthma care can be attributed to physician groups and how reliable those profiling indicators are.

Cross-sectional study. Variations attributable to physician groups are presented using the intraclass correlation coefficient (ICC). The reliability of profiling results was determined using the ICC and sample size of the physician group.

Between July 1998 and February 1999, patients with asthma from 20 California physician groups were randomly selected to be surveyed; 2515 patients responded.

Quality indicators for physician group profiling were (1) National Asthma Education and Prevention Program guideline-based processes of care, including accessibility of asthma care, self-management knowledge about asthma care, use of inhaled bronchodilators, and use of inhaled corticosteroids, and (2) patient outcomes, including satisfaction with asthma care, improvement in health status, and emergency department visits and hospitalizations attributable to asthma.

The variations attributable to physician group were small (< 10%) for process and outcome indicators. For process indicators, self-management knowledge had the highest ICC (9.83%), and use of inhaled bronchodilators had the lowest ICC (3.08%). For outcome indicators, satisfaction with asthma care had the highest ICC (9.53%), and hospitalization had the lowest ICC (1.35%). Despite low ICCs, a large sample size per physician group (n = 126) yielded acceptable reliability (> or = 0.80) for most profiling results.

The selected indicators for profiling asthma care at the physician group level were generally reliable. Sampling a sufficient number of cases is key to achieving useful results from profiling.