Validity of Measured vs. Self-Reported Weight and Height and Practical Considerations for Enhancing Reliability in Clinical and Epidemiological Studies: A Systematic Review

Self-reported measures of height and weight are often used in large epidemiological studies. However, concerns remain regarding the validity and reliability of these self-reported measures. The aim of this systematic review was to summarise and evaluate the comparative validity of measured and self-reported weight and height data and to recommend strategies to improve the reliability of self-reported-data collection across studies. This systematic review adopted the PRISMA guidelines. Four online sources, including PubMed, Medline, Google Scholar, and CINAHL, were utilised. A total of 17,800 articles were screened, and 10 studies were eligible to be included in the SLR based on the defined inclusion and exclusion criteria. The findings from the studies revealed good agreement between measured and self-reported weight and height based on intra-class correlation coefficient and Bland-Altman plots. Overall, measured weight and height had higher validity and reliability (ICC > 0.9; LOA < 1 SD). However, due to biases such as social pressure and self-esteem issues, women underreported their weight, while men overreported their height. In essence, self-reported measures remain valuable indicators to supplement the restricted direct anthropometric data, particularly in large-scale surveys. However, it is essential to address potential sources of bias.

Age-Dependent Association Between Body Mass Index and All-Cause Mortality Among Patients with Hypertension: A Longitudinal Population-Based Cohort Study in China

PURPOSE

The association between body mass index (BMI) and all-cause mortality may vary among hypertensive patients of different ages. This study aimed to investigate the age-dependent association between BMI and all-cause mortality among patients with hypertension.

PATIENTS AND METHODS

A total of 212,394 participants with hypertension aged 20-85 years from Minhang Hypertension Standardization Management System in Shanghai of China were included. Follow-up began at the time when individuals were first recorded and ended at death, loss to follow-up, or December 31, 2018, whichever came first. Additive Cox proportional hazards models with thin plate smoothing functions and conventional Cox proportional hazards models were adopted to examine the relationship between BMI, age, and mortality. The joint effect of BMI and age on mortality was assessed using a bivariate response model.

RESULTS

We found that the BMI-mortality relationship followed a U-shaped pattern, with a trough at 26-27 kg/m2. Compared with normal weight, underweight was associated with a 50% increased risk of premature mortality (hazard ratio 1.50, 95% confidence interval 1.43 to 1.57). Whereas among those aged 45-59 and 60-85 years, overweight was associated with 13% (0.87, 0.80 to 0.94) and 18% (0.82, 0.80 to 0.84) reduction in risk of death, respectively. Bivariate response model indicated a significant interaction between BMI and age (P < 0.05). Among younger and older patients, we found a descending trend for mortality risk, with BMI increasing at different age levels, whereas a reverse J-shaped relation pattern was observed among middle-aged patients.

CONCLUSION

The impact of BMI on all-cause mortality in hypertensive patients varies with age, and moderate weight gain may benefit longevity in middle-aged and older patients.

Developing and validating a Japanese version of the Weight Self-Stigma Questionnaire

PURPOSE

Weight bias internalization (WBI) is significantly associated with negative physiological and psychological consequences. Given its negative effects, appropriate measurement of WBI is required for weight management and mental and physical health in people with weight problems. One of the most reliable and frequently used questionnaires to assess WBI is the Weight Self-Stigma Questionnaire (WSSQ). However, a Japanese version of the WSSQ has not yet been developed. Thus, the current study aimed to develop a Japanese version of the WSSQ (WSSQ-J) and validate its psychometric properties in the Japanese context.

METHODS

A total of 1454 Japanese participants (age 34.44 ± 6.92; male = 498) with diverse weight statuses (Body mass index: 21.44 ± 3.52, 13.79-41.40 kg/m²) completed an online survey for the WSSQ-J. The internal consistency of the WSSQ-J was estimated by calculating Cronbach's α. Confirmatory factor analysis (CFA) was then carried out to confirm that the factor structure of the WSSQ-J was the same as that of the subscales of the original WSSQ.

RESULTS

The WSSQ-J had a Cronbach's α of 0.917, indicating good internal consistency. In CFA, the comparative fit index was 0.945, the root mean square error of approximation was 0.085, and the standardized root mean square residual was 0.040, indicating that the two-factor model showed satisfactory goodness-of-fit.

CONCLUSION

This study replicated the original findings related to the WSSQ, showing that the WSSQ-J is a reliable WBI questionnaire consisting of two factors. Therefore, the WSSQ-J would be a reliable tool for assessing WBI among Japanese.

LEVEL OF EVIDENCE

Level V, descriptive cross-sectional study.