reports

Performance of an ambulatory case-mix measurement in primary care in Spain: Ambulatory Care Groups (ACGs)

Eur J Public Health 9:27-35.

Unitat d’Investigació Centre del Institut Catalá de la Salut, Barcelona, Spain

BACKGROUND: Patient classification systems based on the defining of iso-resources provide useful tools for the analysis, management and financing of health care services. However, their development and application in an ambulatory setting are still in their first steps. Furthermore, these systems, which are often created in the USA, have to be adapted to the characteristics of primary care (PC) in Europe. Because we think that ambulatory care groups (ACGs) can be used in PC, we evaluated their performance in a region of Spain.

METHODS: We used the data from a study based on 13 voluntary doctor and nurse teams which followed a random sample of 2,467 patients for a mean of six months. We used sex, patient age and ICD-9-CM diagnoses of the episodes of care of the patients to assign an ACG to each patient. We used the number of visits, number of episodes, PC cost and total cost per patient as dependent variables to evaluate the ACG performance.

RESULTS: In the ACG distribution obtained, the ten most frequent ACGs accounted for 66% of patients and only two ACG classes were empty. Most ACGs showed a consistent relative weight throughout the different measures of resource use and much lower coefficients of variation for the four dependent variables than the total population. However, ACG 4, 5 and 16 showed a high heterogeneity between the four dependent variables. The ACGs showed an explanatory power of 64% for the number of episodes per patient, 44% for visits per patient, 41% for PC costs and 31% for total costs.

CONCLUSIONS: ACGs cane closest to meeting some theoretical needs of the European PC system with a covered population. The performance of the ACG groups is acceptable and the results obtained are not very different from those obtained by the authors.