OBJECTIVE: To assess the interrelationships between self-rated health, perceptions of long-term illness and diagnoses of chronic diseases.
METHODS:In the World Health Survey, carried out in Brazil in 2003, 5,000 individuals aged 18 years and over who had been selected from a three-stage stratifi ed sample were interviewed. The original questionnaire was adapted for the Brazilian context. It covered the presence of long-term illness or disability, self-rating of health (general and in several domains) and diagnoses of six chronic diseases (arthritis, angina, asthma, depression, schizophrenia and diabetes mellitus). To compare the relationships between self-rated health, perceptions of long-term illness and the chronic diseases evaluated, the statistical test of homogeneity of proportions and multiple logistic regression models were used.
RESULTS:Self-rating of health as "not good" and perceptions of having long-term illnesses were signifi cantly more frequent among women, individuals aged 50 years and over and individuals with one or more of the diseases investigated. The interviewees with a diagnosis of diabetes mellitus presented the worst self-rated health: 70.9% reported having a long-term illness and 79.3% considered that their health was "not good". Worse health ratings were found when two or more diseases were present together. The effect of selfrating of health on the perceptions of long-term illness was stronger than was the number of diseases.
CONCLUSIONS:The three ways of measuring morbidity presented signifi cant interrelationships. Self-rating of health as "not good" had a more important effect on the perceptions of long-term illness, thus suggesting that subjective measurements of health status may be more sensitive for establishing and monitoring individuals' wellbeing.