Which Type of Medical Group Provides Higher-Quality Care?

The quality of medical care depends on the individual physician and on the organization in which he or she works (1–3). In this issue, Mehrotra and colleagues (4) compare 3 types of physician organizations—medical groups, independent practice associations (IPAs), and “hybrids”—on 6 measures of quality. Medical groups are usually defined as organizations in which 3 or more physicians share facilities, staff, and income. Independent practice associations are organizations that contract with health maintenance organizations (HMOs) on behalf of large numbers of medical groups and 1- and 2-physician practices (5, 6). Hybrids, a term coined by the investigators, are organizations that consist of a medical group and an IPA.

Mehrotra and coworkers (4) interviewed the leaders of 119 California physician organizations—97% of the medical groups and IPAs that contracted with PacifiCare (a large HMO) in 1999—querying them about their organization's structure and use of quality improvement processes and electronic medical records (EMRs). They linked their results to PacifiCare data that scored each organization on 6 measures of quality. The mean number of patients per measure per organization ranged from 25 to 3329, depending on the measure. The authors conclude that medical groups scored substantially higher than did IPAs on 4 of the 6 measures: A higher percentage of patients treated by medical groups had mammography, Papanicolaou smears, chlamydia screening, and diabetic retinal examinations. There was no difference between medical groups and IPAs on measures of the use of asthma-control medications and β-blockers after acute myocardial infarction. Hybrid organizations scored better than IPAs but …