Table 2. The results of Kaiser-Meyer-Olkin and Bartlett’s tests
Furthermore, the results obtained from the confirmatory factor analysis according to the fit indicators helped confirm the 4-factor construct of the Persian version of the questionnaire in this study.
The results of analytical fitted statistics reported a good estimate based on the general indicators of the fitted model: chi-square value of 4184.26 (p = 0.000) with a degree of freedom (df) of 1478 and a ratio of 2.83. Given that the significance of the chi-square value can be attributed to the sample size and the robustness, the fitted model statistics suggest that this pattern has provided the best fit for the data because all the statistical values are desirable; in other words, x2/df = 2.23 (which is below 3), GFI = 0.67 and AGFI = 0.64 (which are within the acceptable range of 0 to 1), RMR = 0.11 and SRMR = 0.078 (which are small and near 0), RMSEA = 0.078 (which is within the acceptable range of 0.06 to 0.08), and NFI = 0.95, NNFI = 0.97 and CFI = 0.97 (which are greater than or equal to 0.95).
Pearson correlation coefficient which was obtained from the test-retest statistical method was also calculated at this stage to determine the reliability of the instrument and the intra-class correlation value was reported to be 0.95 (p <0.05). Also, the internal consistency (based on Cronbach’s alpha coefficient) of this instrument was calculated to be 0.97.