Perception of health state and the use of vignettes to calibrate for socioeconomic status: results of the World Health Survey in Brazil, 2003.

As part of the World Health Organization (WHO) project focused on assessing the performance of national health systems, the World Health Survey (WHS) was carried out in many member countries. In order to enable comparison of self-rated health between different cultures of the same country or between different nations, the WHS questionnaire included vignettes of sample cases, that is, hypothetical stories that describe the health problems of third parties. The objective of the present study is to evaluate the possibility of using vignette ratings to implement a socioeconomic calibration scale for self-rated health in Brazil. Using Brazilian WHS data, perceptions of state of health, measured through two different strategies (self-rating and vignette-rating), were compared. The effects of socioeconomic status (educational level and number of household assets) on health domain ratings were estimated via multiple regression models, controlled for age and sex. The effects of socioeconomic status were significant for the majority of health domains in the case of self-perception, but statistically null in the case of third party ratings. It is concluded that the WHO vignettes are not appropriate for calibrating self-rated health measures in Brazil.