Factors associated with spontaneous abortion: a cross-sectional study of Chinese populations

Table 2 The odds ratio of spontaneous abortion associated different socioeconomic status

	Women without SA n = 76,034	Women with SA n = 5,418	Crude OR (95% CI)	Adjusted OR (95% CI) ^a
Region (%)
Urban	45.64	24.73	1.00	1.00
Rural	54.36	75.27	2.56 (2.40–2.72)	1.68 (1.54–1.84)
p for difference ^b			<0.001	<0.001
Annual household income, Yuan (%)
< 20,000	52.68	64.89	1.00	1.00
≥ 20,000	47.32	35.11	0.60 (0.57–0.64)	0.90 (0.84–0.97)
p for trend^c			<0.001	0.003
Highest level of education (%)
Primary school and below	30.05	37.49	1.00	1.00
Middle school	40.72	43.13	0.85 (0.80–0.90)	0.98 (0.92–1.04)
High school and above	29.23	19.38	0.53 (0.49–0.57)	0.90 (0.82–0.98)
p for trend ^c			<0.001	0.033
Current occupation (%)
Agricultural worker and related workers	39.17	59.06	1.00	1.00
Factory worker	25.95	14.29	0.37 (0.34–0.40)	0.59 (0.53–0.66)
Professional worker	16.79	9.93	0.39 (0.36–0.43)	0.75 (0.66–0.84)
Housewife	6.26	7.95	0.84 (0.76–0.94)	1.11 (0.99–1.24)
Unemployed	5.11	3.14	0.41 (0.35–0.48)	0.84 (0.71–1.01)
Other or not stated	6.72	5.63	0.56 (0.49–0.63)	0.95 (0.83–1.09)
p for heterogeneity ^d			<0.001	0.008

NB The COR and AOR in the text represent the crude OR and adjusted OR in the table, respectively
^a Adjustments: rural/urban, income, education, occupation, tea consumption, alcohol consumption, smoking status, induced abortion count
^b p for difference was used to test the difference between rural and urban area as binary variable
^c p for trend was used to test the significance of trend on ordinal categorical variables like income and educational level
^d p for heterogeneity was used to test the heterogeneity between occupation as unordered categorical variables
Bold values signify significant findings p <0.05

ISSN: 1742-4755