ASPO Abstracts
Validity of self-reported weight, height and body mass index among African American breast cancer survivors: the Women’s Circle of Health Follow-Up Study
Category: Lifestyles Behavior, Energy Balance & Chemoprevention, Cancer Health Disparities
Conference Year: 2018
Abstract Body:
Background: Self-reported weight, height and body mass index (BMI) are commonly used in cancer epidemiology studies, but information on the validity of self-reports among cancer survivors is lacking. This study aimed to evaluate the validity of these self- reported measures among African American (AA) breast cancer survivors, known to have a high prevalence of obesity. Methods: We compared the self-reported and measured values among 243 participants from the Women’s Circle of Health Follow-Up Study (WCHFS), a population-based longitudinal study of AA breast cancer survivors. Multivariable-adjusted linear regressions were used to identify factors associated with reporting errors. We also examined the associations of self-reported and measured BMI with obesity-related health outcomes, using hypertension as an example, to evaluate the impact of misreporting. Results: We found that self-reported and measured values were highly correlated among all and when stratified by participants’ characteristics (intraclass correlation coefficients 0.99, 0.84 and 0.96 for weight, height and BMI, respectively). The agreement between BMI categories (normal weight, overweight and obese) based on self-reported and measured data was excellent (kappa: 0.81). Women who were older, never smoked, had higher grade tumors, or had greater BMI tended to have over-estimated BMI calculated from their self-reported weight and height. The BMI-hypertension association was similar using self-reported values (OR per 5 kg/m^2 increase: 1.63; 95% CI: 1.27-2.10; P < 0.001) and measured BMI (1.58; 95% CI 1.23-2.03; P < 0.001). Conclusions: Self-reported weight, height and BMI were reasonably accurate in the WCHFS. Our study supports the use of these self-reported values among cancer survivors when direct measurements are not possible.
Keywords: self-report, body mass index, cancer survivors, African American