Table 3.

Univariate and multivariate analyses for factors related to fertility knowledge in the General group

	Univariate association (n = 4,328)		Multivariate linear regression (n = 3,404, R-squared for model = 0.095)
Variables	Mean (SD)	P	Coefficient a	95% confidence interval	P
Socio-demographic
Gender
Male	40.6 (23.6)		Reference
Female	48.2 (21.9)	<0.001	6.54	4.95 to 8.15	<0.001
Age
Each additional year older	-0.02b	0.16	-0.13	-0.21 to -0.06	<0.001
Annual household income
< 4 million JPY	43.2 (22.4)		Reference
4 - 7 million JPY	45.9 (22.9)		1.43	-0.28 to 3.15	0.10
≥ 8 million JPY	47.0 (23.8)	<0.001	2.57	0.34 to 4.79	0.024
Educational level
No university education	42.4 (22.8)		Reference
University education	47.1 (23.2)	<0.001	3.33	1.73 to 4.93	<0.001
Marital status
Never married	41.7 (23.2)
Ever married	46.0 (22.8)	<0.001
Fertility
Whether or not given birth
Not given birth/fathered a child	43.2 (23.8)		Reference
Given birth/fathered a child	45.7 (22.3)	<0.001	0.84	-0.79 to 2.47	0.31
Whether or not currently trying to conceive
Not currently trying to conceive	43.6 (22.9)		Reference
Currently trying to conceive	54.7 (22.8)	<0.001	6.54	3.62 to 9.46	<0.001
Health-related skills and behaviour
Smoking status
Non-smoking	45.4 (23.2)		Reference
Smoking	40.2 (22.2)	<0.001	-2.29	-4.12 to -0.45	0.015
The score of HLS-14
each additional score higher	0.24c	<0.001	0.52	0.41 to 0.63	<0.001
The score of the Lipkus-J
each additional score higher	0.10c	<0.001	0.90	0.54 to 1.27	<0.001

Note: With regards to annual household incomes, 924 people in the General group who answered “unknown” were excluded from the analysis.

^aNon-standardized coefficient. ^bPearson’s correlation coefficient.

^cSpearman’s correlation coefficient.