Table 3.

Perinatal mortality (22⁺⁰ weeks – 6 days) risk per region after adjustment for risk factors.

	Unadjusted		Adjusted Model I#		Adjusted Model II†
	OR	95% CI	OR	95% CI	OR	95% CI
Region
North	1.11	1.03–1.19	1.20	1.12–1.28	1.11	1.03–1.20
East	1.01	0.96–1.07	1.08	1.02–1.14	1.04	0.98–1.10
West*	1.00	reference	1.00	reference	1.00	reference
South	0.95	0.90–1.00	1.01	0.95–1.06	0.97	0.91–1.03
Maternal age
< 20 years	1.68	1.49–1.91	1.38	1.22–1.57	1.36	1.20–1.54
20–34 years	1.00	reference	1.00	reference	1.00	reference
≥ 35 years	1.23	1.17–1.30	1.28	1.21–1.35	1.29	1.23–1.36
Parity
Parity 0	1.40	1.33–1.47	1.42	1.35–1.49	1.42	1.35–1.49
Parity 1	1.00	reference	1.00	reference	1.00	reference
Parity 2+	1.44	1.36–1.53	1.32	1.24–1.41	1.31	1.23–1.40
Ethnicity
Western	1.00	reference	1.00	reference	1.00	reference
Non-Western	1.42	1.35–1.50	1.43	1.36–1.50	1.37	1.29–1.45
Urbanization
Very urban	1.10	1.05–1.16			0.92	0.86–0.98
Middle	1.00	reference			1.00	reference
Very rural	1.01	0.96–1.07			1.03	0.98–1.10
SES
Low	1.23	1.18–1.30			1.15	1.09–1.21
Middle	1.00	reference			1.00	reference
High	0.90	0.85–0.95			0.91	0.86–0.96

* Region west was set as reference area as the perinatal mortality rate of this region was equal to the overall rate.

^# Model I was adjusted for maternal age, parity and ethnicity.

^† Model II was an extension of model I with additional adjustment for degree of urbanization and SES.