RESUMO
INTRODUCTION: Although chronic and subacute subdural haematomas (CSSH) are amongst the commonest neurosurgical conditions, there are few studies on their incidence in the general population. OBJECTIVES: To determine the overall annual rate, the specific rates according to age and sex based on the Official Argentinian National Census of 1991 (OANC 91) for CSSH. PATIENTS AND METHODS: The Hospital Privado de Comunidad de Mar del Plata attends a captive population of 89,500 persons from the Instituto Nacional de Servicios Sociales de Jubilados y Pensionados (INSSJP) and the Prepaid Medical Schemes (PMP) of our institution. We studied the patients of INSSJP and PMP who had CSSH between 1992 and 1996. We determined the annual overall rate and the specific rates according to age and sex, and fitted to the OANC 91. RESULTS: 1. Annual overall rate: 14.1 CSSH/100,000 persons/year. 2. Specific rate for women: 11.6 CSSH/100,000 persons/year. 3. Specific rate for men: 18.1 CSSH/100,000 persons/year. 4. Specific rate 71-80 years old: 18.8 CSSH/100,000 persons/year. 5. Rate fitted to OANC9: 3.1 CSSH/100,000 persons/year. CONCLUSIONS: Our overall rate is higher, and the specific rate for the age group 71-80 years is intermediate, with regard to the rates found in other studies. Neuroepidemiological investigation should be stimulated so that more clinical studies are made regarding the results and costs based on the population.