Assessing the validity of self-reported weight, height, and body mass index among hispanic breast cancer survivors.

Self-reported measurements of body size are commonly used in cancer epidemiological studies; however, inaccuracies may lead to misclassification of body mass index (BMI) and biased estimates of associations with health outcomes. Despite their widespread use, the validity of these self-reported measures has not been well established among Hispanic breast cancer survivors, a growing and understudied population. This is particularly important, as prior research suggests that the accuracy of self-reported anthropometric measures may vary across racial and ethnic groups, highlighting the need for population-specific validation. To address this gap, we compared self-reported and measured weight, height, and BMI among 192 Hispanic women participating in the New Jersey Breast Cancer Survivors Study using intraclass correlation coefficients (ICCs), Bland-Altman analyses, and Cohen's kappa, and examined predictors of reporting error using multivariable regression models. Data were collected during home visits, including body measurements taken by research staff and interviewer-administered questionnaires on body size and related factors. Self-reported and measured values were highly correlated (Intraclass correlation coefficients (95% Confidence Intervals (CI)): 0.99 (0.99, 0.99), 0.8 (0.64, 0.88), 0.95 (0.92, 0.97) for weight, height, and BMI, respectively). The agreement between self-reported and measured BMI categories (normal, overweight, and obese) was strong (kappa: 0.85; 95% CI: 0.79, 0.91). The mean difference observed between self-reported and measured BMI (-0.67 kg/m2) was primarily explained by slight over-reporting of height (mean difference: 1.94 cm). These findings support the use of self-reported weight, height, and BMI measures in large epidemiologic studies of Hispanic/ Latina cancer survivors when direct measurements are not feasible.