Comparability and reproducibility of adult male anogenital distance measurements for two different methods

The distance from the genitals to the anus, anogenital distance, reflects androgen concentration during prenatal development in mammals. The use of anogenital distance in human studies is still very limited and the quality and consistency of measurements is an important methodological issue. The aim of this study was to assess the feasibility and reproducibility of adult male anogenital distance measurements by two different methods. All men were attending an outpatient clinic at a university hospital and underwent an andrological examination and completed a brief questionnaire. Two variants of anogenital distance [from the anus to the posterior base of the scrotum (AGD_AS) and to the cephalad insertion of the penis (AGD_AP)] by two methods (lithotomy or frog-legged position) were assessed in 70 men. Within and between coefficient of variations, intra-class correlation coefficients, two-way repeated-measures analysis of variance, and scatter and Bland–Altman plots were calculated. The two methods produced similar values for AGD_AP but different estimates for AGD_AS. Nonetheless, the overall agreement (ICC ≥ 0.80) was acceptable for both measures. Therefore, both methods are internally consistent and adequate for epidemiological studies, and may be used depending on the available medical resources, clinical setting, and populations.