Reliability, Validity and Factor Structure of the Polish Version of the Massachusetts General Hospital Hair Pulling Scale

Purpose The Massachusetts General Hospital Hairpulling Scale (MGH-HPS) is a 7-item self-report tool that measures hair-pulling behaviors. The study aimed to assess the psychometric properties of the Polish version of the MGH-HPS in a sample of adults. Methods The online screening survey was completed by 1024 participants (777 women, 241 men, 6 non-binary), 92 of which (68 women, 24 men) were included in the study because they confirmed engaging in hair-pulling behaviors at least occasionally; 23 of those (2.25% of the initial sample) met the DSM-5 criteria for hair-pulling disorder. The participants were asked to complete the online version of the MGH-HPS, the Depression Anxiety Stress Scales-21-Item Version, the Obsessive Compulsive Inventory-Revised, and a scale containing the DSM-5 hair-pulling disorder criteria. The factor structure, reliability, validity, and diagnostic accuracy of the Polish version of the MGH-HPS were examined. Results The confirmatory factor analysis demonstrated that both a one-factor and a two-factor model fit the data well; however, given the high correlation between the factors, the unidimensional model may be superior. High internal consistency and convergent and divergent validity were obtained for the total score of the MGH-HPS and the Severity and Resistance and Control factors (Cronbach’s alphas: 0.89, 0.85 and 0.84 respectively). The ROC analysis indicated adequate prognostic ability of the total score to discriminate subjects with clinical and non-clinical hair-pulling. The optimal cut-off value was 13 points (sensitivity = 100%, specificity = 62.22%). Conclusions The Polish version of the MGH-HPS is a valid, reliable tool which may be used to measure hair-pulling behaviors in adult samples.