BACKGROUND: Although female pattern hair loss (FPHL) has been considered simply the female counterpart of male pattern hair loss in men, the risk factors may differ. OBJECTIVE: We sought to evaluate factors associated with FPHL and to estimate its prevalence in women. METHOD: In total, 26,226 subjects aged 30 years and older participated in a cross-sectional survey. Ludwig and Norwood classifications were used to assess the degree of hair loss. Information on possible risk factors for FPHL was collected using a questionnaire interview. RESULTS: The prevalence of FPHL (Ludwig grade >I) for all ages was 11.8% (95% CI 11.5%-12.2%), increasing with advancing age. After controlling for age and family history, statistically significant associations were noted between FPHL and high fasting glucose (odds ratio [OR] 1.15, 95% confidence interval [CI] 1.04-1.28), fewer childbirths (OR 1.24, 95% CI 1.12-1.38), breast-feeding (OR 0.88, 95% CI 0.78-0.98), oral contraceptive use (OR 1.21, 95% CI 1.01-1.45), and ultraviolet exposure more than 16 hours per week (OR 1.12, 95% CI 1.02-1.22). LIMITATIONS: The validity and reliability of FPHL classification may be not perfect in this survey and may need to be verified. Information on family history may be still subject to recall bias. CONCLUSIONS: Risk factors for FPHL and male androgenic alopecia may differ.
BACKGROUND: Although female pattern hair loss (FPHL) has been considered simply the female counterpart of male pattern hair loss in men, the risk factors may differ. OBJECTIVE: We sought to evaluate factors associated with FPHL and to estimate its prevalence in women. METHOD: In total, 26,226 subjects aged 30 years and older participated in a cross-sectional survey. Ludwig and Norwood classifications were used to assess the degree of hair loss. Information on possible risk factors for FPHL was collected using a questionnaire interview. RESULTS: The prevalence of FPHL (Ludwig grade >I) for all ages was 11.8% (95% CI 11.5%-12.2%), increasing with advancing age. After controlling for age and family history, statistically significant associations were noted between FPHL and high fasting glucose (odds ratio [OR] 1.15, 95% confidence interval [CI] 1.04-1.28), fewer childbirths (OR 1.24, 95% CI 1.12-1.38), breast-feeding (OR 0.88, 95% CI 0.78-0.98), oral contraceptive use (OR 1.21, 95% CI 1.01-1.45), and ultraviolet exposure more than 16 hours per week (OR 1.12, 95% CI 1.02-1.22). LIMITATIONS: The validity and reliability of FPHL classification may be not perfect in this survey and may need to be verified. Information on family history may be still subject to recall bias. CONCLUSIONS: Risk factors for FPHL and male androgenic alopecia may differ.