Study objectives: The aim of the current survey was to investigate the prevalence of sleep complaints in a randomized cluster sample of the Brazilian population.
Methods: A 3-stage cluster sampling technique was utilized to randomly select Brazilian subjects older than 16 years, of both genders and all socioeconomic classes. The final sample of 2,110 subjects from 150 different cities was enough to estimate prevalence in the Brazilian population with a sampling error of +/- 2%. Questions about sleep complaints were administered face-to-face by Instituto Datafolha interviewers on March 26 and 27, 2008. Data were expanded using a weighted variable.
Results: Of all interviewed subjects, 63% reported at least one sleep related complaint. Sleep complaint prevalence increased with age and was similar among inhabitants of different Brazilian regions, as well as between metropolitan areas and smaller cities. Insomnia and nightmares were significantly more prevalent in women (40% and 25%, respectively), and snoring was more prevalent in men (35%). For sleep complaints with frequencies greater than 3 times per week, we found the following prevalence: 61% for snoring, 35% for insomnia, 17% for nightmares, 53% for leg kicking, and 37% for breathing pauses.
Conclusions: Because sleep disorders are affect a high proportion of the population and are known to be correlated with decreased wellbeing and productivity, more detailed national surveys are necessary to provide relevant information to develop approaches to prevention and treatment.