Reliability and Validity of a Photo Rating Measure of Alopecia

Numerous studies of trichotillomania (TTM) incorporate measures of the extent of alopecia (hair loss) resulting from hair pulling. This study used data from a clinical trial of stepped care for TTM to provide further evidence pertaining to a 1–7 alopecia rating scale (Tolin et al. 2002). Ratings were based on photographs of participants’ (N = 60) most severely affected pulling site. Alopecia rating proved highly acceptable (88 % completed the assessment), stable (10-week retest reliability r for wait-listed participants = 0.63), and convergently valid (r = 0.51 with an interviewer’s rating of hair loss based on live observation). Alopecia ratings were not significantly related to self-rated social impairment resulting from TTM, nor with total symptom severity. Hair regrowth rate varies by sex, age, and pulling site, so alopecia rating cannot serve as a direct marker of TTM treatment progress. Nonetheless, it appears to be a reliable and valid measure of a consequence of pulling that is of great concern to people with TTM. Future research should examine its potential treatment utility as a means of giving patients feedback on the side effects of progress they are making in therapy.