This study developed a practical method for determining the functional outcome status of patients in an ambulatory setting. Health status of 1,840 primary care patients was compared at three points in time: patient's usual status, status at the initial visit, and status at time of telephone follow-up. Follow-up status was also compared with the physician's expectation, which was estimated at the time of the initial visit. Of the patients, 62% showed improvement, 31% remained at the same level, and 7% deteriorated from the time of their initial clinic visit. Physicians tended to overestimate either the speed or degree with which patients return to their usual functional status; 32% of the patients studied reported themselves as being less well than usual at the time of follow-up.