RESUMO
In order to estimate morbidity by acute respiratory infections in an adult population, a study was carried out in four health areas of City of Havana, to know the real morbidity and the one assisted for this population group. A sample was selected from 10 physicians' offices at each health area, and in each one of them a random sample of 40 families was taken, that at least should include 400 elderly people of 65 years old or more. A semi-monthly visit was done to each selected family for over a year, by an interviewer trained with that purpose. Incidence rate found in adults from 15 to 64 years was of 509.5 for 1,000 years/persons, almost three times the rate reported by the inactive surveillance, and in elders of 65 years and more it was of 943.8 for 1,000 years/persons, 8.8 times the rate reported by inactive surveillance.