An Investigation of Validity and Reliability of Entrapment Scale in the Students of Isfahan University of Medical Sciences, Iran

Currently, Allen & Gilbert’s entrapment scale is used in order to measure entrapment in different countries. Therefore, this research was carried out with the aim of investigating the validity and reliability of entrapment scale in the students of Isfahan University of Medical Sciences. A total of 162 students (60 males and 102 females) of Isfahan University of Medical Sciences were selected by simple random sampling and responded to the research tools. To examine the validity of entrapment scale, methods including content validity, item-total correlation (material analysis) and subtest-total correlation (factors analysis) were applied, and in order to examine the scale’s reliability, methods including Cronbach’s alpha and split-half were used. Significance level was considered to be 0.01 (99% confidence). Analysis of the questionnaire’s items demonstrated that item-total correlation coefficients were significant in all cases and varied in the range of 0.44-0.76. The subtest-total correlation coefficient with the total score was determined 0.95 for external entrapment subscale and 0.90 for internal entrapment subscale (p<0.01). Also, factors analysis indicated the presence of two general factors. In addition, by using Cronbach’s alpha coefficient, the internal reliability of the scale for total scale and subscales of the external and internal entrapment subscales were calculated 0.92, 0.87, 0.88, respectively. The split-half reliability coefficient of the scale was obtained 0.88. All in all, the results of this research demonstrated that entrapment scale has satisfying psychometric properties for use in Iranian students.