Differentials and income-related inequalities in maternal depression during the first two years after childbirth: birth cohort studies from Brazil and the UK

Table 5 Relative index of inequality (RII) for maternal depression by time ranked by family income in the ALSPAC and the Pelotas birth cohort studies.

Time points	Unadjusted analysis		P*	Adjusted analysis**		P*
	ALSPAC RII (95% CI)	Pelotas RII (95% CI)		ALSPAC RII (95% CI)	Pelotas RII (95% CI)
Time 1 ^a	3.25 (2.50; 4.22)	3.17 (1.56; 6.42)	0.948	2.86 (1.90; 4.30)	1.58 (0.67; 3.74)	0.246
Time 2 ^b	2.35 (1.79; 3.08)	3.51 (2.60; 4.74)	0.043	2.05 (1.34; 3.15)	2.33 (1.65; 3.31)	0.234
Time 3 ^c	3.43 (2.65; 4.43)	3.01 (2.25; 4.02)	0.511	2.91 (1.93; 4.39)	2.25 (1.60; 3.16)	0.743

^a at 8 weeks and 3 months after delivery for ALSPAC and Pelotas birth cohort, respectively
^b at 8 and 12 months after delivery for ALSPAC and Pelotas birth cohort, respectively
^c at 21 and 24 months after delivery for ALSPAC and Pelotas birth cohort, respectively
* significance of the difference between ALSPAC and Pelotas birth cohort study
** adjusted for race, age, marital status, parity, pre-pregnancy body mass index, antenatal risk, smoking during pregnancy, multiple birth and neonatal problems.