Objective: The aim of this study is to analyze the validity and reliability
of the Turkish form of Massachusetts General Hospital Hairpulling Scale
(MGH-HPS), which is used to measure the severity of Trichotillomania
(TTM).
Methods: Fifty patients diagnosed with TTM according to the DSM-5
diagnostic criteria and fifty healthy controls participated in the study. The
participants were asked to complete a sociodemographic questionnaire,
the MGH-HPS-TR, the Clinical Global Impression (CGI), the Beck
Depression Inventory (BDI), the Beck Anxiety Inventory (BAI) and
the Barratt Impulsiveness Scale (BIS-11). The construct validity and
the criterion validity of the MGH-HPS-TR were determined by means
of exploratory factor analysis (EFA) and confirmatory factor analysis
(CFA), respectively. The reliability analysis of the MGH-HPS-TR was
assessed by calculating the Cronbach’s α coefficient and the item total
correlation coefficient. The values for the area under the curve (AUC),
sensitivity and specificity were based on the ROC analysis.
Results: AFA and CFA results indicated a single factor structure with 7
items explaining 82.5% of the variance. The item/factor loadings were
satisfactory with the best fit indeces. Correlations were found between
the scores on the MGH-HPS-TR and the other scales used for criterion
validity analyses. The internal consistency and the item-total correlation
coefficients of the scale were found to be satisfactory. Based on a cut of
point of ≥ 9, the scale had high power for discriminating between the
patient and the control groups and high sensitivity and specificity.
Conclusion: This study showed that the MGH-HPS-TR can be used as
a valid and reliable psychometric tool in Turkey.
Keywords: Trichotillomania, reliability, validity, scale, hair pulling,
body focused repetetive behaviour