Limitations of case-mix systems in primary care: comparison of the severity of patients in community hospitals and health care centers in the United States
Fernández de Sanmamed, M.J.; Fein, O.; Morrison, A.; Moy, E.
Atencion Primaria 12(3): 144-147
1993
ISSN/ISBN: 0212-6567 PMID: 8338905 Document Number: 417958
The aim was to show the limitations of the case-mix "based on attendance", which take into account neither the seriousness of the diagnoses nor the comorbidity. A crossover descriptive study of a retrospective nature. In New York, in two centres located in the Hispanic community of Upper Manhattan and a third in the Presbyterian Hospital. During 1991, 225 patients were studied: 150 attended in the hospital PCC and 75 in the non-hospital PCCs. A simple random sampling of the list of patients attended was performed. The seriousness of the conditions of the patients attended in the two different types of PCC was compared through the Duke Severity of Illness Scale (DUSOI), a patient-based case-mix which assesses the level of seriousness of each individual diagnosis and the comorbidity linked to the diagnoses grouped together. Significant differences between the seriousness of the conditions of the patients in the two sub-samples were found when comparison by means of bivariant analysis was performed. Scoring on the Severity Scale was significantly higher for those attending hospital (65.5 and 55.1 respectively). Patient classification systems based on the reasons for attendance underestimate the seriousness of the condition. A case-mix in which the patient is the unit of analysis needs to be developed.