Sources of heterogeneity in studies of the BMI-mortality association

• Main Author: Raphael Simon Peter
• Format: Article
• Language: English
• Published: Japan Epidemiological Association 2017-06-01
• Series: Journal of Epidemiology
• Subjects: Body mass index; Mortality; Heterogeneity
• Online Access: https://www.jstage.jst.go.jp/article/jea/27/6/27_27_294/_pdf
• ISSN: 0917-5040; 1349-9092

Background: To date, the amount of heterogeneity among studies of the body mass index-mortality association attributable to differences in the age distribution and length of follow-up has not been quantified. Therefore, we wanted to quantify the amount of heterogeneity attributable to age and follow-up in results of studies on the body mass index-mortality relation. Methods: We used optima of the body mass index mortality association reported for 30 populations and performed meta-regression to estimate the amount of heterogeneity attributable to sex, ethnicity, mean age at baseline, percentage smokers, and length of follow-up. Results: Ethnicity as single factor accounted for 36% (95% CI, 11–56%) of heterogeneity. Mean age and length of follow-up had an interactive effect and together accounted for 56% (95% CI, 24–74%) of the remaining heterogeneity. Sex did not significantly contribute to the heterogeneity, after controlling for ethnicity, age, and length of follow-up. Conclusions: A considerable amount of heterogeneity in studies of the body mass index-mortality association is attributable to ethnicity, age, and length of follow-up.