Quality assessment: is the focus on providers or on patients?

Most studies of ambulatory care quality are based on chart reviews of episodes of care in single settings, rather than on care received by a patient over time and across settings. The purpose of this study was to compare ambulatory care quality scores based on information from the usual source of care to scores based on information from all providers seen during a year. The quality of well child care for 55 two-year-olds and asthma care for 70 children and adults continuously enrolled in the Maryland Medicaid program throughout 1988 was assessed. Combining data from multiple providers changed quality scores in both directions. For well child care, quality scores generally improved because of an increased opportunity to perform desirable actions, such as lead screening. However, quality scores for asthma care generally decreased because undesirable clinician actions, such as the failure to document follow-up plans, increased as more problems were uncovered. Thus, the findings of quality assessments differ according to whether the focus is on care delivered by individual providers or on care received by patients. The direction of the difference will depend upon whether the indicators of quality represent omission of recommended care or commission of improper care.