Table 2. Multivariable logistic regression model for the association between subjects’ characteristics and SHS exposure at workplace among non-smoking employees (n=8196).

	SHS exposure
	At least once a week		At least several times a week
	Cigarettes	HTPs	Cigarettes	HTPs
	Adjusted OR (95% CI)	Adjusted OR (95% CI)	Adjusted OR (95% CI)	Adjusted OR (95% CI)
Workplace smoke-free policy
Complete smoking bans	1 (reference)	1 (reference)	1 (reference)	1 (reference)
Partial smoking bans with no longer available smoking spaces	2.06 (1.60 to 2.65)	4.15 (3.22 to 5.34)	1.43 (1.04 to 1.97)	3.23 (2.37 to 4.39)
Partial smoking bans with still available smoking spaces	1.92 (1.63 to 2.25)	2.24 (1.86 to 2.71)	1.85 (1.54 to 2.23)	2.03 (1.62 to 2.54)
No smoking bans	5.33 (4.10 to 6.93)	3.88 (2.86 to 5.26)	5.15 (3.90 to 6.8)	4.22 (3.03 to 5.89)
Sex
Male	1.65 (1.42 to 1.91)	1.77 (1.47 to 2.13)	1.50 (1.26 to 1.79)	1.72 (1.38 to 2.14)
Female	1 (reference)	1 (reference)	1 (reference)	1 (reference)
Age (years)
15–29	2.20 (1.62 to 2.99)	2.80 (1.89 to 4.15)	1.86 (1.30 to 2.65)	1.98 (1.24 to 3.16)
30–49	1.74 (1.33 to 2.26)	2.11 (1.49 to 2.99)	1.56 (1.15 to 2.12)	1.91 (1.27 to 2.87)
50–64	1.31 (1.00 to 1.72)	1.62 (1.13 to 2.32)	1.22 (0.89 to 1.67)	1.44 (0.95 to 2.2)
65–79	1 (reference)	1 (reference)	1 (reference)	1 (reference)
Marital status
Married	1 (reference)	1 (reference)	1 (reference)	1 (reference)
Never married	1.07 (0.92 to 1.25)	1.03 (0.85 to 1.23)	1.12 (0.93 to 1.34)	1.04 (0.84 to 1.3)
Widowed/Divorced	1.30 (1.03 to 1.65)	1.25 (0.93 to 1.68)	1.26 (0.96 to 1.66)	1.29 (0.92 to 1.81)
Educational level
High school or below	2.02 (1.72 to 2.36)	1.74 (1.43 to 2.11)	2.30 (1.92 to 2.76)	2.14 (1.71 to 2.69)
College	1.33 (1.12 to 1.59)	1.30 (1.05 to 1.61)	1.43 (1.16 to 1.76)	1.55 (1.20 to 1.99)
4-year university or above	1 (reference)	1 (reference)	1 (reference)	1 (reference)
Equivalent household income
<2.75 million JPY	1.35 (1.12 to 1.63)	1.32 (1.06 to 1.65)	1.73 (1.38 to 2.15)	1.62 (1.23 to 2.12)
2.75–4.5 million JPY	1.18 (0.99 to 1.39)	1.10 (0.90 to 1.35)	1.33 (1.08 to 1.64)	1.26 (0.98 to 1.62)
>4.5 million JPY	1 (reference)	1 (reference)	1 (reference)	1 (reference)
Did not know/Did not want to answer	1.18 (0.95 to 1.48)	1.10 (0.84 to 1.45)	1.57 (1.21 to 2.03)	1.47 (1.07 to 2.03)
Regional infection status of COVID-19
Low	1 (reference)	1 (reference)	1 (reference)	1 (reference)
Middle	0.96 (0.82 to 1.12)	1.01 (0.83 to 1.21)	0.88 (0.73 to 1.06)	0.94 (0.75 to 1.18)
High	0.90 (0.77 to 1.05)	0.94 (0.78 to 1.14)	0.89 (0.75 to 1.07)	0.89 (0.71 to 1.11)
Recognition of the adverse health effects of SHS exposure
No	1.31 (1.09 to 1.58)	1.77 (1.43 to 2.18)	1.43 (1.15 to 1.77)	1.67 (1.30 to 2.14)
Neither yes nor no	1.12 (0.95 to 1.31)	1.31 (1.08 to 1.59)	1.13 (0.93 to 1.36)	1.20 (0.95 to 1.5)
Yes	1 (reference)	1 (reference)	1 (reference)	1 (reference)
Self-rated health status
Good	1 (reference)	1 (reference)	1 (reference)	1 (reference)
Normal	1.13 (0.98 to 1.3)	1.06 (0.90 to 1.26)	1.07 (0.91 to 1.26)	1.13 (0.92 to 1.38)
Bad	1.41 (1.17 to 1.7)	1.52 (1.22 to 1.9)	1.33 (1.07 to 1.66)	1.50 (1.16 to 1.96)
Employment pattern
Permanent employee	1.86 (1.41 to 2.44)	1.51 (1.09 to 2.1)	1.91 (1.39 to 2.63)	1.72 (1.17 to 2.53)
Company executive	2.06 (1.42 to 2.99)	1.95 (1.27 to 3)	2.23 (1.45 to 3.44)	1.99 (1.19 to 3.33)
Temporary employee	1.23 (0.87 to 1.73)	0.98 (0.64 to 1.49)	1.13 (0.75 to 1.70)	0.92 (0.55 to 1.53)
Part-time employee	1.35 (0.99 to 1.83)	1.09 (0.75 to 1.58)	1.22 (0.85 to 1.74)	1.05 (0.67 to 1.64)
Self-employed	1 (reference)	1 (reference)	1 (reference)	1 (reference)
Labour type
Manual labour	1.46 (1.27 to 1.69)	1.28 (1.07 to 1.52)	1.40 (1.19 to 1.65)	1.13 (0.92 to 1.4)
Non-manual labour	1 (reference)	1 (reference)	1 (reference)	1 (reference)

HTPsheated tobacco productsJPYJapanese yenSHSsecondhand smoke