Measurement Properties and Optimal Cutoff Point of the WHO-5 Among Chinese Healthcare Students

Figures & data

Table 1 Sociodemographic Variables (N = 343)

Variables	N (%)	Mean (SD)
		Baseline	Follow-Up
Gender
Male	127 (37.026)	57.732 (17.168)	57.827 (18.425)
Female	216 (62.974)	56.741 (17.873)	58.167 (18.578)
Age
< 20 years	150 (43.732)	58.800 (17.264)	60.773 (17.468)
≥ 20 years	193 (56.268)	55.793 (17.785)	55.917 (19.030)
Major
Clinical medicine	154 (44.898)	53.039 (17.232)	54.883 (19.518)
Preventive medicine	189 (55.102)	60.423 (17.234)	60.614 (17.246)
Home location
Urban	156 (45.481)	58.179 (17.885)	59.256 (19.050)
Rural	101 (29.446)	56.356 (18.401)	57.188 (17.786)
Suburban	86 (25.073)	56.047 (16.135)	56.837 (18.367)
Being only child
Yes	128 (37.318)	57.094 (16.864)	57.531 (19.246)
No	215 (62.682)	57.116 (18.058)	58.344 (18.072)
Monthly household income
< 10,000 CNY	141 (41.108)	55.489 (18.663)	57.135 (19.197)
≥ 10,000 CNY	202 (58.892)	58.238 (16.767)	58.673 (18.010)
Part-time job
Yes	33 (9.621)	56.364 (17.360)	57.333 (18.806)
No	310 (90.379)	57.187 (17.648)	58.116 (18.491)
Physical exercise
Yes	257 (74.927)	58.646 (17.513)	59.564 (18.532)
No	86 (25.073)	52.512 (17.134)	53.488 (17.720)
Hobby
Yes	244 (71.137)	58.639 (17.849)	59.770 (18.492)
No	99 (28.863)	53.333 (16.443)	53.778 (17.891)
Frequency of visiting home
Frequently	51 (14.869)	63.294 (17.283)	62.824 (17.386)
Occasionally	292 (85.131)	56.027 (17.456)	57.205 (18.584)
Stress coping strategy
Emotion-focused	189 (55.102)	58.455 (16.103)	59.111 (17.952)
Solution-focused	121 (35.277)	57.983 (18.656)	59.240 (18.757)
Avoidance coping	33 (9.621)	45.182 (18.550)	47.515 (17.798)

Abbreviations: SD, standard deviation; Mean (SD), mean scores and SDs of the Chinese World Health Organization-Five Well-Being Index.

Table 2 Model Fit Indices of the Single-Factor Model for the WHO-5-C (N = 343)

	χ^2 (df)	P	CFI	TLI	RMSEA (90% CI)	SRMR
Baseline	42.372 (5)	< 0.001	0.968	0.937	0.148 (0.109, 0.190)	0.028
Follow-up	35.051 (5)	< 0.001	0.980	0.961	0.132 (0.093, 0.175)	0.020
Threshold	N/A	> 0.050	≥ 0.900	≥ 0.900	≤ 0.080	≤ 0.080

Abbreviations: WHO-5-C, Chinese World Health Organization-Five Well-Being Index; χ², chi-square; df, degrees of freedom; CFI, comparative fit index; TLI, Tucker-Lewis index; RMSEA, root mean square error of approximation; CI, confidence interval; SRMR, standardized root mean square residual; N/A, not applicable.

Table 3 Cross-Sectional Measurement Invariances of the WHO-5-C (N = 343)

Hypothesis	Baseline							Follow-up
	χ^2 (df)	P	Δχ^2 (Δdf)	CFI	ΔCFI	TLI	SRMR	χ^2 (df)	P	Δχ^2 (Δdf)	CFI	ΔCFI	TLI	SRMR
Gender (male vs female)
Configural	52.934 (10)	< 0.001		0.964		0.929	0.027	41.874 (10)	< 0.001		0.979		0.959	0.018
Metric	55.992 (14)	< 0.001	3.058 (4)	0.965	0.001	0.950	0.037	51.370 (14)	< 0.001	9.496 (4)	0.976	−0.003	0.965	0.044
Scalar	63.280 (18)	< 0.001	7.288 (4)	0.962	−0.003	0.958	0.042	55.458 (18)	< 0.001	4.088 (4)	0.976	0.000	0.973	0.046
Strict	79.479 (23)	< 0.001	16.200 (5)*	0.953	−0.009	0.959	0.041	65.966 (23)	< 0.001	10.508 (5)	0.972	−0.004	0.976	0.046
Age (< 20 years vs ≥ 20 years)
Configural	49.244 (10)	< 0.001		0.967		0.934	0.025	41.665 (10)	< 0.001		0.979		0.958	0.018
Metric	57.824 (14)	< 0.001	8.580 (4)	0.963	−0.004	0.947	0.051	49.650 (14)	< 0.001	7.985 (4)	0.976	−0.003	0.966	0.043
Scalar	70.454 (18)	< 0.001	12.630 (4)*	0.956	−0.007	0.951	0.058	54.244 (18)	< 0.001	4.594 (4)	0.976	0.000	0.973	0.046
Strict	74.182 (23)	< 0.001	3.728 (5)	0.957	0.001	0.963	0.054	59.088 (23)	< 0.001	4.844 (5)	0.976	0.000	0.979	0.046
Major (clinical medicine vs preventive medicine)
Configural	46.837 (10)	< 0.001		0.968		0.936	0.026	42.164 (10)	< 0.001		0.979		0.958	0.019
Metric	57.528 (14)	< 0.001	10.691 (4)*	0.962	−0.006	0.946	0.060	58.085 (14)	< 0.001	15.921 (4)	0.971	−0.008	0.958	0.056
Scalar	63.445 (18)	< 0.001	5.917 (4)	0.961	−0.001	0.956	0.064	70.981 (18)	< 0.001	12.895 (4)	0.965	−0.006	0.961	0.063
Strict	69.586 (23)	< 0.001	6.140 (5)	0.960	−0.001	0.965	0.062	78.824 (23)	< 0.001	7.844 (5)	0.963	−0.002	0.968	0.059
Home location (urban vs rural vs suburban)
Configural	52.121 (15)	< 0.001		0.969		0.938	0.028	47.354 (15)	< 0.001		0.979		0.958	0.020
Metric	56.444 (23)	< 0.001	4.323 (8)	0.972	0.003	0.963	0.042	50.249 (23)	0.001	2.895 (8)	0.982	0.003	0.977	0.031
Scalar	71.353 (31)	< 0.001	14.909 (8)	0.966	−0.006	0.967	0.051	57.660 (31)	0.003	7.411 (8)	0.983	0.001	0.983	0.037
Strict	85.508 (41)	< 0.001	14.155 (10)	0.963	−0.003	0.973	0.056	69.440 (41)	0.004	11.780 (10)	0.981	−0.002	0.986	0.036
Threshold	N/A	> 0.050	N/A	≥ 0.900	≤ 0.010	≥ 0.900	≤ 0.080	N/A	> 0.050	N/A	≥ 0.900	≤ 0.010	≥ 0.900	≤ 0.080
Being only child (yes vs no)
Configural	55.642 (10)	< 0.001		0.962		0.923	0.027	45.525 (10)	< 0.001		0.977		0.954	0.019
Metric	57.227 (14)	< 0.001	1.585 (4)	0.964	0.002	0.948	0.031	55.883 (14)	< 0.001	10.358 (4)	0.973	−0.004	0.961	0.051
Scalar	58.106 (18)	< 0.001	0.879 (4)	0.966	0.002	0.962	0.032	58.072 (18)	< 0.001	2.189 (4)	0.974	0.001	0.971	0.052
Strict	59.867 (23)	< 0.001	1.760 (5)	0.969	0.003	0.973	0.032	63.610 (23)	< 0.001	5.539 (5)	0.974	0.000	0.977	0.048
Monthly household income (<10,000 CNY vs ≥10,000 CNY)
Configural	52.339 (10)	< 0.001		0.964		0.928	0.028	42.364 (10)	< 0.001		0.979		0.958	0.019
Metric	54.249 (14)	< 0.001	1.911 (4)	0.966	0.002	0.951	0.035	46.149 (14)	< 0.001	3.785 (4)	0.979	0.000	0.970	0.036
Scalar	59.468 (18)	< 0.001	5.219 (4)	0.965	−0.001	0.961	0.038	49.460 (18)	< 0.001	3.311 (4)	0.979	0.000	0.977	0.038
Strict	60.943 (23)	< 0.001	1.475 (5)	0.968	0.003	0.972	0.037	52.133 (23)	< 0.001	2.673 (5)	0.981	0.002	0.983	0.038
Part-time job (yes vs no)
Configural	47.502 (10)	< 0.001		0.968		0.937	0.026	37.583 (10)	< 0.001		0.982		0.964	0.018
Metric	53.590 (14)	< 0.001	6.088 (4)	0.966	−0.002	0.952	0.038	39.405 (14)	< 0.001	1.822 (4)	0.983	0.001	0.976	0.022
Scalar	54.664 (18)	< 0.001	1.075 (4)	0.969	0.003	0.966	0.038	39.965 (18)	0.002	0.559 (4)	0.986	0.003	0.984	0.023
Strict	56.380 (23)	< 0.001	1.716 (5)	0.972	0.003	0.975	0.037	43.980 (23)	0.005	4.015 (5)	0.986	0.000	0.988	0.023
Physical exercise (yes vs no)
Configural	48.218 (10)	< 0.001		0.967		0.934	0.027	45.160 (10)	< 0.001		0.977		0.953	0.018
Metric	49.586 (14)	< 0.001	1.368 (4)	0.969	0.002	0.956	0.031	46.897 (14)	< 0.001	1.737 (4)	0.978	0.001	0.969	0.023
Scalar	55.063 (18)	< 0.001	5.477 (4)	0.968	−0.001	0.965	0.034	50.420 (18)	< 0.001	3.523 (4)	0.979	0.001	0.976	0.025
Strict	58.785 (23)	< 0.001	3.722 (5)	0.969	0.001	0.973	0.036	55.071 (23)	< 0.001	4.651 (5)	0.979	0.000	0.982	0.028
Threshold	N/A	> 0.050	N/A	≥ 0.900	≤ 0.010	≥ 0.900	≤ 0.080	N/A	> 0.050	N/A	≥ 0.900	≤ 0.010	≥ 0.900	≤ 0.080
Hobby (yes vs no)
Configural	45.443 (10)	< 0.001		0.970		0.939	0.025	41.634 (10)	< 0.001		0.979		0.958	0.018
Metric	54.322 (14)	< 0.001	8.879 (4)	0.966	−0.004	0.951	0.047	45.428 (14)	< 0.001	3.794 (4)	0.979	0.000	0.970	0.030
Scalar	60.352 (18)	< 0.001	6.030 (4)	0.964	−0.002	0.960	0.051	50.697 (18)	< 0.001	5.269 (4)	0.978	−0.001	0.976	0.033
Strict	64.862 (23)	< 0.001	4.511 (5)	0.964	0.000	0.969	0.049	58.747 (23)	< 0.001	8.050 (5)	0.976	−0.002	0.979	0.033
Frequency of visiting home (frequently vs occasionally)
Configural	59.381 (10)	< 0.001		0.958		0.916	0.030	44.238 (10)	< 0.001		0.978		0.955	0.020
Metric	60.465 (14)	< 0.001	1.084 (4)	0.961	0.003	0.944	0.033	55.843 (14)	< 0.001	11.604 (4)	0.973	−0.005	0.961	0.034
Scalar	67.474 (18)	< 0.001	7.010 (4)	0.958	−0.003	0.953	0.037	63.186 (18)	< 0.001	7.343 (4)	0.970	−0.003	0.967	0.036
Strict	74.911 (23)	< 0.001	7.437 (5)	0.956	−0.002	0.962	0.037	64.914 (23)	< 0.001	1.728 (5)	0.972	0.002	0.976	0.038
Stress coping strategy (emotion-focused vs solution-focused vs avoidance coping)
Configural	64.714 (15)	< 0.001		0.957		0.914	0.030	56.192 (15)	< 0.001		0.973		0.945	0.021
Metric	72.264 (23)	< 0.001	7.550 (8)	0.958	0.001	0.945	0.047	61.663 (23)	< 0.001	5.471 (8)	0.974	0.001	0.967	0.040
Scalar	84.429 (31)	< 0.001	12.165 (8)	0.954	−0.004	0.955	0.052	72.893 (31)	< 0.001	11.230 (8)	0.972	−0.002	0.973	0.044
Strict	97.831 (41)	< 0.001	13.402 (10)	0.951	−0.003	0.964	0.060	86.189 (41)	< 0.001	13.296 (10)	0.970	−0.002	0.978	0.044
Threshold	N/A	> 0.050	N/A	≥ 0.900	≤ 0.010	≥ 0.900	≤ 0.080	N/A	> 0.050	N/A	≥ 0.900	≤ 0.010	≥ 0.900	≤ 0.080

Note: *P < 0.05.

Abbreviations: WHO-5-C, Chinese World Health Organization-Five Well-Being Index; χ², chi-square; df, degrees of freedom; CFI, comparative fit index; TLI, Tucker-Lewis index; SRMR, standardized root mean square residual; Δ, change in χ², df, and CFI; N/A, not applicable.

Table 4 Longitudinal Measurement Invariances of the WHO-5-C (N = 343)

Hypothesis	χ^2 (df)	P	Scaled Chi-Square Difference Test Statistics		CFI	ΔCFI	TLI	ΔTLI	RMSEA (90% CI)	ΔRMSEA	SRMR	ΔSRMR
			Δχ^2 (Δdf)	P
Configural	94.419 (29)	< 0.001			0.980		0.968		0.081 (0.063, 0.100)		0.022
Metric	95.342 (33)	< 0.001	0.923 (4)	0.921	0.980	0.000	0.973	0.005	0.074 (0.057, 0.092)	−0.007	0.024	0.002
Scalar	99.464 (37)	< 0.001	4.122 (4)	0.390	0.980	0.000	0.976	0.003	0.070 (0.054, 0.087)	−0.004	0.025	0.001
Strict	125.095 (42)	< 0.001	25.631 (5)	< 0.001	0.974	−0.006	0.972	−0.004	0.076 (0.061, 0.091)	0.006	0.027	0.002
Threshold	N/A	> 0.050	N/A	> 0.050	≥ 0.900	≤ 0.010	≥ 0.900	≤ 0.010	≤ 0.080	≤ 0.015	≤ 0.080	≤ 0.030

Abbreviations: WHO-5-C, Chinese World Health Organization-Five Well-Being Index; χ², chi-square; df, degrees of freedom; CFI, comparative fit index; TLI, Tucker-Lewis index; RMSEA, root mean square error of approximation; CI, confidence interval; SRMR, standardized root mean square residual; Δ, change in χ², df, CFI, TLI, RMSEA, and SRMR; N/A, not applicable.

Figure 1 Inter-item and item-total correlations between the Chinese WHO-5, PHQ-4, and SRHQ (N=343).

Abbreviations: WHO-5, World Health Organization-Five Well-Being Index; WHO01-05, item 01–05 of the WHO-5; PHQ-2, Patient Health Questionnaire-2; GAD-2, Generalized Anxiety Disorder-2; PHQ-4, Patient Health Questionnaire-4; SRHQ, Self-Rated Health Questionnaire; T1, Time 1; T2, Time 2.

Table 5 Internal Consistency and Test–Retest Reliability of the WHO-5-C, SRHQ, and PHQ-4-C (N = 343)

Scales	Cronbach’s α		McDonald’s ω		ICC (95% CI)	SEM
	Baseline	Follow-Up	Baseline	Follow-Up		Baseline	Follow-Up
WHO-5-C	0.907 (0.891, 0.922)	0.934 (0.923, 0.945)	0.908 (0.893, 0.924)	0.935 (0.924, 0.946)	0.803 (0.762, 0.838)	7.810	8.209
WHO-5-C01	0.883 (0.863, 0.903)	0.915 (0.900, 0.929)	0.885 (0.865, 0.905)	0.915 (0.900, 0.930)	0.796 (0.754, 0.832)	6.578	6.875
WHO-5-C02	0.877 (0.857, 0.898)	0.914 (0.899, 0.929)	0.881 (0.860, 0.901)	0.915 (0.901, 0.930)	0.799 (0.757, 0.834)	6.394	6.682
WHO-5-C03	0.865 (0.843, 0.888)	0.906 (0.890, 0.921)	0.865 (0.841, 0.888)	0.904 (0.887, 0.921)	0.785 (0.741, 0.822)	6.484	6.820
WHO-5-C04	0.905 (0.889, 0.921)	0.930 (0.918, 0.942)	0.905 (0.889, 0.922)	0.931 (0.918, 0.943)	0.791 (0.748, 0.828)	6.521	6.772
WHO-5-C05	0.898 (0.881, 0.916)	0.930 (0.918, 0.942)	0.900 (0.883, 0.918)	0.931 (0.919, 0.943)	0.798 (0.756, 0.833)	6.347	6.712
SRHQ	0.727	0.805	N/A	N/A	0.749 (0.697, 0.793)	0.637	0.675
PHQ-4-C	0.818 (0.786, 0.849)	0.846 (0.820, 0.872)	0.820 (0.789, 0.851)	0.849 (0.823, 0.875)	0.681 (0.620, 0.734)	1.234	1.263

Note: The McDonald’s ω and the 95% CI of Cronbach’s α cannot be calculated due to the SRHQ containing only 2 items.

Abbreviations: WHO-5-C, Chinese World Health Organization-Five Well-Being Index; WHO-5-C_01-05, item 01–05 of the WHO-5-C was deleted; SRHQ, Self-Rated Health Questionnaire; PHQ-4-C, Chinese Patient Health Questionnaire-4; ICC, intraclass correlation coefficient; CI, confidence interval; SEM, standard error of measurement, calculated as “SD × sqrt (1-ICC)”.

Table 6 Sensitivity and Specificity of the WHO-5-C for Identifying Well-Being in Healthcare Students (N = 343)

WHO-5-C	PHQ-2-C		Total	Sensitivity	Specificity
	< 3	≥ 3
≥ 50	211	13	224	0.803	0.762
< 50	66	53	119
Total	277	66	343

Abbreviations: WHO-5-C, Chinese World Health Organization-Five Well-Being Index; PHQ-2-C, Chinese Patient Health Questionnaire-2.

Figure 2 ROC curve of the Chinese WHO-5 for well-being (N=343).

Abbreviations: WHO-5, World Health Organization-Five Well-Being Index; ROC, receiver operating characteristic; AUC, area under the curve.