Problems of case finding and data collection in ambulatory care settings.

The experience gained in a four-year ambulatory care study suggests that major problems of patient care data collection include: 1) Difficulties in obtaining listings of patients by diagnosis/condition that accurately reflect the actual practice experience; 2) Inaccurate coding or identification of the reason for patient visits; and 3) Inability to find the medical record within the system. Data presented here suggest there are certain regularities in completion rates characteristic of research sites and of diagnostic categories.