The Chinese version of the Perceived Stress Questionnaire: development and validation amongst medical students and workers

Table 6 Reliability of the Chinese between PSQ-13 and PSQ-30 (N = 2798)

	Quality criteria	PSQ-13	PSQ-30
Mean ± SD^a	N/A	0.414 ± 0.158	0.429 ± 0.155
Item-total correlation	0.30–0.70	0.453–0.688	0.319–0.698
Cronbach’s alpha (α)	0.70–0.95	0.878	0.935
Guttman’s lambda-2 (λ₂)	> 0.70	0.880	0.937
McDonald’s omegas (ω)	> 0.70	0.880	0.937
Split-half reliability coefficient	> 0.70	0.852	0.919
Test–retest correlation (N = 122)^b	> 0.70	0.782 [0.679, 0.853]	0.874 [0.800, 0.920]
Intraclass correlation coefficient (ICC) for absolute agreement (N = 122)^b	> 0.75 or 0.70	0.805 [0.729, 0.861]	0.899 [0.858, 0.929]
Standard error of measurement^c	N/A	0.070	0.049

Note:
N/A not applicable;
^a, The PSQ Index was used, SD = standard deviation; Sample A (N = 122, first time) has to be merged into total sample (N = 2798);
^b, 95% Confidence Interval estimation of test-retest correlation used bootstrap, all Spearman correlation P < 0.001;
^c, Standard error of measurement was calculated as SD × sqrt (1-ICC)

ISSN: 1477-7525