Reliability and validity of self-reported male balding patterns for use in epidemiologic studies.

PURPOSE: To evaluate the validity and reliability of self-reported male balding patterns in an epidemiologic study.
METHODS: Participants were 100 men 50-76 years old who were randomly selected from a cohort study of over 77,000 men and women. To assess hair patterning, men selected from among 3 sets of pictures that best described their hair patterning at age 30, at age 45, and at their current age. The categories were little or no hair loss, frontal baldness, and vertex baldness. The self-reporting was done a second time 3 months later. An interviewer independently assessed each man's current hair patterning using the same classification scheme.
RESULTS: Test-retest reliability (kappa) of self-reported hair patterning was 0.74, 0.71, and 0.81 for age 30, age 45, and current age, respectively. The kappa for the comparison of the subject's report of current hair patterning to the interviewer's assessment was 0.47.
CONCLUSION: Hair patterning represents a noninvasive biomarker that may be an indicator of increased disease risk. While trained observers may represent the gold standard, our study indicates that men are fairly accurate in self-reporting their balding patterns and are quite reliable in reporting their hair patterning at earlier ages.