Validity of a self-reported measure of familial history of obesity
1 Department of Food Science and Nutrition, Institute of Nutraceuticals and Functional Food Laval University, Quebec, Canada, and Lipid Research Center, CHUQ-CHUL Pavilion, 2705 Laurier Blvd, TR-93, Sainte-Foy, Quebec, G1V 4G2, Canada
2 Department of Social and Preventive Medicine, Laval University, Quebec, G1K 7P4, Canada
3 Faculty of Nursing, Laval University, Quebec, Canada, G1K 7P4 and Canada Research Chair on Behaviour and Health, Quebec, G1K 7P4, Canada
4 Department of Food Science and Nutrition, Institute of Nutraceuticals and Functional Food Laval University, Quebec, Canada, and Lipid Research Center, CHUQ-CHUL Pavilion, 2705 Laurier Blvd, TR-93, Sainte-Foy, Quebec, G1V 4G2, Canada
Nutrition Journal 2008, 7:27 doi:10.1186/1475-2891-7-27Published: 10 September 2008
Familial history information could be useful in clinical practice. However, little is known about the accuracy of self-reported familial history, particularly self-reported familial history of obesity (FHO).
Two cross-sectional studies were conducted. The aims of study 1 was to compare self-reported and objectively measured weight and height whereas the aims of study 2 were to examine the relationship between the weight and height estimations reported by the study participants and the values provided by their family members as well as the validity of a self-reported measure of FHO. Study 1 was conducted between 2004 and 2006 among 617 subjects and study 2 was conducted in 2006 among 78 participants.
In both studies, weight and height reported by the participants were significantly correlated with their measured values (study 1: r = 0.98 and 0.98; study 2: r = 0.99 and 0.97 respectively; p < 0.0001). Estimates of weight and height for family members provided by the study participants were strongly correlated with values reported by each family member (r = 0.96 and 0.95, respectively; p < 0.0001). Substantial agreement between the FHO reported by the participants and the one obtained by calculating the BMI of each family members was observed (kappa = 0.72; p < 0.0001). Sensitivity (90.5%), specificity (82.6%), positive (82.6%) and negative (90.5%) predictive values of FHO were very good.
A self-reported measure of FHO is valid, suggesting that individuals are able to detect the presence or the absence of obesity in their first-degree family members.