Reanalyzing the modified Ferriman-Gallwey (mFG) score: is there a simpler method for assessing the extent of hirsutism?

Abstract

OBJECTIVE: To determine whether assessing the extent of terminal hair growth in women presenting for evaluation of androgen excess, using a subset of the traditional 9 body areas included in the modified Ferriman Gallwey(mFG) score can serve as a sufficiently reliable and simpler predictor of total body hirsutism when compared to the full scoring method. DESIGN: Cross-sectional study MATERIALS AND METHODS: 1094 women presenting with symptoms suggestive of androgen excess were evaluated by physical exam including hirsutism evaluation using the mFG scoring method. All exams were performed by one examiner, blood samples were taken, and data was analyzed using a best subset linear regression model. RESULTS: Of all the individual body area scores, the lower abdomen served as the best individual predictor of total body hirsutism as determined by the mFG score. This score, however, did not serve as a reliable proxy for total mFG score with a variability of +/-6.8 points in 95% of patients (R2 = 45%). A regression model using all nine body areas indicated that a combination of the upper abdomen, lower abdomen, and chin was able to predict the total mFG score within +/- 2.5 points in 95% of patients (R2=78.7%). By increasing the subset of body areas to four, the most predictive combination included the lower abdomen, upper abdomen, chin, and thigh. This subset only minimally increases the ability to predict the total body mFG hirsutism score (R2=79.6), and is a more invasive exam when compared to the subset of three. Thus the best subset of three was chosen as the mFG proxy. The equation below can be used to approximate the total mFG score: mFG hirsutism score proxy = (lower abdomen + upper abdomen + chin) x 1.8. All relationships were found to be independent of age. CONCLUSIONS: The combination of hair growth scores from the upper abdomen, lower abdomen and chin can serve as a reliable, simpler and less invasive predictor of the total mFG score when compared to the traditional mFG scoring method.