Comparison of self-reported and directly measured weight and height among women of reproductive age: a systematic review and meta-analysis.

INTRODUCTION: The use of self-report as a strategy for collecting data on women's weight and height is widespread in both clinical practice and epidemiological studies. This study aimed to compare self-reported and directly measured weight and height among women of reproductive age.

MATERIAL AND METHODS: In July 2015 we searched MEDLINE, EMBASE, COCHRANE, CINHAL, LILACS and gray literature. We included women of reproductive age (12-49 years old) independently of their weight or height at the time of the study. Women with any condition that implies regular tracking of their weight (for example, eating disorder) were excluded. Two reviewers independently selected, extracted and assessed the risk of bias of the studies. We used REVMAN 5.3 to perform the meta-analysis. Heterogeneity was assessed using the I2 statistic.

RESULTS: Following eligibility assessment, 21 studies of 18 749 women met the inclusion criteria. The results of the meta-analysis showed an underestimation of weight by -0.94 kg (95% CI -1.17 to -0.71 kg; p < 0.0001; I2  = 0%) in the overall sample and an overestimation of height by 0.36 cm (95% CI 0.20-0.51; p < 0.0001; I2  = 35%) based on self-reported vs. directly measured values.

CONCLUSION: This review shows that self-reported weight and height of women of reproductive age differs slightly from direct measures. We consider that the magnitude at which self-reported data over- or underestimates the real value, is negligible regarding clinical and research use.