The investigation of validity and reliability of the Turkish version of the Brief self-control scale

Abstract

The investigation of validity and reliability of the Turkish version of the Brief Self-Control Scale Objective: The Learned Resourcefulness Scale has been utilized to measure self-control in research in Turkey. However, this scale may not be appropriate to measure the trait of self-control. For this reason, we aimed to adapt the Brief Self-Control Scale (BSCS), which was developed by Tangney, Baumeister, and Boone (2004), into Turkish. Methods: The validity and reliability tests were conducted with 523 participants who were not diagnosed with any psychiatric disorder. Discriminant validity was investigated by assessment with the BSCS, the social skills subscale of the Tromso Social Intelligence Scale (TSIS), the controlling negative body responses and anger management subscales of the Emotional Management Skills Scale (EMSS), and the BIS-11 on 36 euthymic bipolar I disorder patients (according to the DSM-IV-TR criteria) and 50 individuals without a psychiatric diagnosis. Test-retest reliability was done with 145 people who were chosen from among the 523 participants. Results: For language equivalency of the BSCS, the relationships between the English and Turkish versions of the BSCS were investigated using Pearson correlation and they were found to be r=0.72 for impulsiveness, r=0.76 for self-discipline, and r=0.73 for the total scale. To determine the factor structure of the BSCS, principal component analysis and varimax were used, and the analysis yielded two-factors called impulsiveness and self-discipline. The two-factor structure of the BSCS was confirmed by confirmation factor analysis. For criterion-related validity, correlations among subscales of the BSCS and social skills of the TSIS, controlling negative body responses and anger management subscales of the EMSS and the BIS-11 were utilized. They ranged from r=-0.11 to r=0.64 for impulsiveness, and r=0.19 to r=0.63 for self-discipline. The discriminant ability of impulsivity and self-discipline between euthymic bipolar I disorder patients and individuals without any psychiatric diagnosis were investigated by using discriminant analysis and it was confirmed that they could discriminate. ROC analysis indicated that impulsiveness and self-discipline differentiated between euthymic bipolar I disorder patients and the individuals without psychiatric diagnosis (area under the curve 0.85 and 0.82, respectively), while the BSCS Total did not differentiate (area under the curve 0.56). Using a cut-off score of 13 for impulsiveness, sensitivity was 0.806, specificity was 0.84, positive predictive value was 0.04, negative predictive value was 0.99, positive likelihood ratio was 5.03, and negative likelihood ratio was 0.23. Using a cut-off score of 12 for self-discipline, sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio and negative likelihood ratio were 0.917, 0.62, 0.02, 0.99, 2.41 and 0.13, respectively. Conclusion: The results indicated that the BSCS is a reliable and valid instrument. On the other hand, utilizing the scale as a part of a screening process rather than a diagnostic or sole screening tool would be better, as positive and negative predictive values indicated that there was a fair percentage of false negatives and positives.