With the aid of a continuity index (K), ranged from 0 to 100% and previously described, a comparison has been made in a primary care district before and after the opening of a new health care centre. An organization with health care teams seems to have contributed to a considerable improvement in continuity. The K index increased from 28 to 69% for scheduled and acute visits taken together. About 90% of the visits to the ordinary district physicians were made by people living in the "correct" geographical area. The corresponding figure as regards visits to the district nurse and nurse was 97%. When the service time at a health centre, not organised with health care teams, was expanded and the number of physicians increased, the K index rose from 43 to 54%. When three positions as full-time physicians were divided into six half-time, the K index dropped from 53% to 42%. In order to assess the K index, it was compared to three other measures (UPC, COC and SECON). They all tended to give fairly similar results when applied to empirical data, although the K index required less detailed data to compute. Therefore, the K index can be considered to be a worthwhile measure to use, when analyzing the effects of organizational changes.