The Québec Child and Adolescent Health and Social Survey: design and methods of a cardiovascular risk factor survey for youth.

BACKGROUND Although atherosclerosis begins in childhood, there are no recent Canadian data on cardiovascular risk factors in provincially or nationally representative samples of youth. OBJECTIVE To describe the design and methods of the 1999 Québec Child and Adolescent Health and Social Survey, which assessed the prevalence and distribution of risk factors in a representative sample of Québec youth. METHODS School-based, multistage, cluster sampling survey of youth aged nine, 13 and 16 years. Measures included height, weight, subscapular and tricipital skinfolds, blood pressure (measured with the Dinamap), a fasting blood draw for assessment of lipoproteins and glucose, an age-adapted youth questionnaire on lifestyles and a parent questionnaire. RESULTS One thousand two hundred sixty-seven, 1186 and 1160 subjects aged nine, 13 and 16 years, respectively, responded to the questionnaire and had height, weight, skinfold thickness and blood pressure measured (response proportions of 83%, 79% and 78% respectively); 783, 818 and 874 subjects of the same age agreed to the blood draw (response proportions of 52%, 55% and 59%, respectively). Comparisons of characteristics of participants and nonparticipants in the blood draw showed few differences. The mean relative difference between lipoprotein and glucose values obtained at the study laboratory and a reference method varied from -0.3% to 6.1%. Design effects for means and proportions varied from 1.0 to 1.8. CONCLUSION Despite its complexity, this survey was able to achieve a high level of precision for multiple measures. It will provide the most complete data on cardiovascular risk factors ever collected among children and adolescents in Canada.