Table 4.

Parameter estimates of the selected ARIMA models for daily COVID-mention among help-seekers in Open Up (Open Up, CMD, and No CMD) in the four waves of COVID-19 outbreak

Daily	ARIMA model	Parameter	Estimate	Standard error	p	AIC	SBC
Open Upa	1st wave	MUb	0.29	1.07	0.785	129	132
		COVIDc	0.50	0.44	0.254
		COVIDt−1d	−0.89	0.44	0.042
	2nd wave	No model fit
	3rd wave	MU	−0.20	1.61	0.902	399	406
		AR1e	0.51	0.12	<0.001
		COVID	0.08	0.04	0.023
	4th wave	No model fit
CMDf	1st wave	MU	0.32	0.80	0.689	117	120
		COVID	0.34	0.33	0.296
		COVIDt−1	−0.68	0.33	0.040
	2nd wave	No model fit
	3rd wave	MU	−0.45	1.99	0.821	368	372
		AR1	0.70	0.09	<0.001
	4th wave	MU	0.01	0.62	0.990	387	392
		AR1	0.27	0.12	0.021
NO CMDg	1st wave	No model fit
	2nd wave	No model fit
	3rd wave	MU	0.00	0.30	1.000	280	284
		COVID	0.04	0.01	<0.001
	4th wave	No model fit

^aSelected ARIMA model for COVID-mention.

^bIntercept.

^cCOVID-19 reported cases in Hong Kong.

^dCOVID-19 reported cases in Hong Kong, lagged by one day.

^eAutoregressive, lagged by one day.

^fSelected ARIMA model for CMD- mention subgroup.

^gSelected ARIMA model for non-CMD mention subgroup.