Quality of medical care: a factor analysis approach using medical records.

A relatively inexpensive, reliable, and unobtrusive method is described for measuring the content of medical care. Factor analysis of the content of the records of more than 11,000 physician-patient encounters from six different health insurance plans extracted four main factors or dimensions that together explained 42 percent of the variance in record content. Appropriate names for these dimensions appear to be: "prevention," "rationality," "verification," and "continuity." The method is tested by scoring the six insurance plans on the four factors.