Table 2 . C-section rates, crude odds ratio, adjusted odds ratio and adjusted population attributable risks (aPAR %) according to reproductive factors in Southwest Iran, 2012 .

Risk factors	CS rate (%)	n	Crud odds ratio (95%CI)	Adjusted odds ratio (95%CI)	PAR%
Parity
1	65.84	2026	1	1
2	60.06	1262	0.78 (0.67- 0.92)	0.72 (0.58- 0.88)	-11.2
3	60.24	586	0.78 (0.65- 0.94)	0.67 (0.52- 0.87)	-6.6
4+	52.19	343	0.56 (0.44- 0.71)	0.42 (0.31- 0.58)	-9.41
Type of pregnancy
Wanted	62.65	3518	1.11 (0.94- 1.31)	*
Unwanted	60.09	699	1	*
Previous miscarriage stillbirth
Yes	65.49	794	1.18 (1.01- 1.39)	1.59 (1.30- 1.94)	7.35
No	61.47	3423	1	1
Number of miscarriage
One time	64.51	603	1	*
Two times	66.90	145	1.11 (0.75- 1.63)	*
Three and more than three times	75	46	1.65 (0.81- 3.33)	*
Previous Abnormalities
Yes	73.68	57	1.71 (0.94- 3.09)	*
No	62.07	4160	1	*
Previous infertility
Yes	76.71	292	2.09 (1.58- 2.76)	2.06 (1.55- 2.73)	4.39
No	61.15	3925	1	1	1
Gestational age (week)
<32	69.44	108	1	*
32-36	78.05	246	1.56 (0.94- 2.60)	*
37-41	60.90	3790	0.68 (0.45- 1.03)	*
>42	67.12	73	0.89 (0.47- 1.69)	*
Birth weight(g)
<3000	66.42	1751	1	1
3000-3499	61.16	1331	0.79 (0.68- 0.92)	0.74 (0.64- 0.85)	-10.89
3500-3999	56.36	928	0.65 (0.55- 0.76)	0.80 (0.68- 0.94)	-4.98
>4000	59.90	207	0.75 (0.56- 1.01)	*
Number of live birth
0	66.94	1564	1	1
1	60.14	1533	0.74 (0.64- 0.86)	0.96 (0.79- 1.16)	-1.14
2	57.25	821	0.66 (0.55- 0.78)	0.93 (0.75- 1.16)	-1.34
>3	61.87	299	0.8 (0.62- 1.03)	*

*Since these variables have no significant association with outcome in form crude analysis, so in multiple analysis were not entered the model.