Accuracy of self-reported height, weight and waist circumference in rural poor areas of China

Abstract Background There were different voices about the accuracy of self-reported data. This study was to assess awareness and accuracy of self-reported height, weight and waist circumference (WC) among adult residents in rural poor areas of China for the first time. Methods Multi-stage stratified cluster random sampling was used to sample. Intraclass correlations (ICCs), Bland-Altman plots with limits of agreements (LOAs), Cohen’s kappa were used to examine the accuracy. Multi-factor Logistics and multiple linear regression were used to explore the effect of demographic and socioeconomic variables. Results Awareness rate of height, weight and WC were 66.29%, 82.29% and 60.00%, respectively. Height was over-reported 0.67 cm, weight and WC were under-reported 0.00 kg and 1.09 cm. ICC for height was 0.92, weight was 0.93 and WC was 0.93. Mostly differences were within 95% LOAs, but 95% LOAs were wide, especially WC. The percentage agreement (kappa) for BMI was 82.10% (0.71), for WC were 83.56% (0.66). Overall, obesity, overweight and increased WC were underestimated by 0.56%, 2.64% and 6.89%, respectively. Regression analysis showed some demographic and socioeconomic variables could affect the awareness and accuracy. Conclusions The self-reported height and weight could be used in rural poor areas of China, but the WC should be used with caution. The main task now is to further improve the awareness rate and accuracy of self-reported data, especially the people with low awareness rate and accuracy in certain subgroups. In addition, differences from the developed countries should be more discussed and investigated: all others showed people tend to under-reported weight, but the self-reported weight is amazingly accurate in our study; and contrary to studies in developed county, we found people tend to under-report WC.