Chinese public’s knowledge, perceived severity, and perceived controllability of COVID-19 and their associations with emotional and behavioural reactions, social participation, and precautionary behaviour: a national survey

Table 2 Psychometric properties of the measures used in this study

	Reliability	Item discrimination of each measure ^a		Model fit of confirmatory factor analysis (CFA) ^d
	α	t ^b	p	χ²	df	CFI	RMSEA	90%CI	SRMR
1. Knowledge about the COVID-19	0.91	[−63.90, −45.57]	< 0.001	386.87	24	0.99	0.06	[0.052, 0.062]	0.02
2. Perceived severity	0.84	[−65.61, −52.08]	< 0.001	62.06	3	1.00	0.07	[0.052, 0.080]	0.02
3. Perceived controllability	0.91	[−93.59, −49.78]	< 0.001	135.78	17	1.00	0.04	[0.033, 0.045]	0.01
4. Emotional and behavioural reactions
Negative emotion	0.91	[−59.46, −34.28]	< 0.001	192.48	8	0.99	0.07	[0.062, 0.080]	0.02
Positive emotion	0.97	[− 115.87, − 114.46]	< 0.001	e	e	e	e	e	e
Sleep problem	0.91	[−42.78, −29.82]	< 0.001	24.11	2	0.99	0.05	[0.033, 0.067]	0.01
Aggression	0.90	[−60.09, −22.67]	< 0.001	f	f	f	f	f	f
Substance use	0.91	[−27.75, −15.85]	< 0.001	f	f	f	f	f	f
Mobile phone use	–	−101.18 ^c	< 0.001	f	f	f	f	f	f
5. Social participation	0.79	[− 70.45, −47.41]	< 0.001	23.71	3	1.00	0.04	[0.025, 0.054]	0.01
6. Precautionary behaviour	0.92	[−55.19, −33.11]	< 0.001	2950.96	121	0.96	0.07	[0.069, 0.073]	0.08

^a: The ability of each item in a measure/dimension to differentiate the high (top 27%) and the low (bottom 27%) total score of that measure/dimension was examined
^b: T-values of the comparison between the high and the low total score groups in the item discrimination tests are presented as a range. For instance, the measure of “Knowledge about the COVID-19” consists of 11 items; the range represents the t values of the comparison for these 11 items
^c: The “mobile phone use” dimension has only 1 item and thus no range is presented
^d: Some residuals are correlated when we fit the CFA models for some measures/dimensions
^e: This dimension has 3 items and thus the CFA model is a saturated model (i.e., χ² = 0.00, df = 0.00, CFI = 1.00, RMSEA and SRMR = 0.00)
^f: Each of these dimensions has less than 3 items and thus CFA is not applicable

ISSN: 1471-2458