Table 3.

Predictors of depression severity: incidence rate ratios from a Poisson regression model.

Variable	Model 1		Model 2
	Depression severity		Depression severity
	IRR (95% CI)	p-value	IRR (95% CI)	p-value
Living arrangement
Single household (=reference)	1		1
Two-person household	0.85 (0.75, 0.90)	***	0.81 (0.75, 0.89)	***
Three-person household	0.81 (0.73, 0.89)	***	0.74 (0.65, 0.85)	***
Four or more person household	0.87 (0.78, 0.90)	*	0.87 (0.76, 0.99)	*
Year
2018 (=reference)	1		1
2020 (COVID-19)	0.98 (0.93, 1.04)		0.91 (0.76, 1.09)
Household × Year
Single × COVID-19			1.01 (0.82, 1.25)
Two-person × COVID-19			1.10 (0.90, 1.34)
Three-person × COVID-19			1.22 (0.96, 1.56)
Gender
Male (=reference)	1		1
female	1.06 (1.01, 1.13)	*	1.06 (1.01, 1.13)	*
Age
65–69 (=reference)	1		1
70–74	0.99 (0.92, 1.06)		0.99 (0.93, 1.06)
75–79	1.08 (0.98, 1.16)		1.09 (0.98, 1.18)
80 or more	1.07 (0.99, 1.17)		1.07 (0.87, 1.16)
Marital status
Married (=reference)	1		1
Not-married	1.14 (0.88, 1.47)		1.12 (0.69, 1.45)
Household income category
3 (middle = reference)	1		1
1 (lowest)	1.11 (1.02, 1.22)	*	1.11 (1.02, 1.22)	*
2 (low)	0.96 (0.88, 1.06)		0.96 (0.87, 1.05)
4 (high)	0.99 (0.78, 1.11)		0.98 (0.87, 1.11)
5 (highest)	0.92 (0.80, 1.06)		0.90 (0.78, 1.04)
Education
No formal education (=reference)	1		1
6 years	0.93 (0.86, 1.00)		0.93 (0.86, 1.01)
7–12 years	0.92 (0.84, 1.00)	*	0.91 (0.84, 0.99)	*
13 years +	0.65 (0.57, 0.75)	***	0.65 (0.57, 0.75)	***
Employment status
Unemployed (=reference)	1		1
Employed	0.86 (0.82, 0.92)	***	0.86 (0.81, 0.92)	***
House ownership
No (=reference)	1		1
Yes	0.87 (0.82, 0.92)	***	0.87 (0.82, 0.92)	***
Subjective stress status
Almost never (=reference)	1		1
Feels a little	1.11 (1.02, 1.20)	*	1.11 (1.02, 1.20)	*
Feels stressed	1.86 (1.71, 2.03)	***	1.86 (1.71, 2.03)	***
Feels very stressed	2.67 (2.40, 2.96)	***	2.65 (2.38, 2.94)	***

*p < 0.05; ***p < 0.001.