Gender norms and modern contraceptive use in urban Nigeria: a multilevel longitudinal study.

Background: Evidence suggests that gender equality positively influences family planning. However, the evidence from urban Africa is sparse. This study aimed to examine the association between changes in gender norms and modern contraceptive use over time among women in urban Nigeria.

Methods: Data were collected in 2010/2011 from 16,118 women aged 15-49 living in six cities in Nigeria (Abuja, Benin, Ibadan, Ilorin, Kaduna, and Zaria) and again in 2014 from 10,672 of the same women (34% attrition rate). The analytical sample included 9933 women living in 480 neighborhoods. A four-category outcome variable measured their change in modern contraceptive use within the study period. The exposure variables measured the changes in the level of gender-equitable attitudes towards: a) wife beating; b) household decision-making; c) couples' family planning decisions; and d) family planning self-efficacy. Multilevel multinomial logistic regression models estimated the associations between the exposure variables at the individual and neighborhood levels and modern contraceptive use controlling for the women's age, education, marital status, religion, parity, household wealth, and city of residence.

Results: The proportion of women who reported current use of modern contraceptive methods increased from 21 to 32% during the four-year study period. At both surveys, 58% of the women did not report using modern contraceptives while 11% reported using modern contraceptives; 21% did not use in 2010/2011 but started using by 2014 while 10% used in 2010/2011 but discontinued use by 2014. A positive change in the gender-equitable attitudes towards household decision-making, couples' family planning decisions, and family planning self-efficacy at the individual and neighborhood levels were associated with increased relative probability of modern contraceptive use (adoption and continued use) and decreased relative probability of modern contraceptive discontinuation by 2014. No such associations were found between the individual and neighborhood attitudes towards wife beating and modern contraceptive use. Accounting for the individual and neighborhood gender-equitable attitudes and controlling for the women's demographic characteristics accounted for 55-61% of the variation between neighborhoods in the change in modern contraceptive use during the study period.

Conclusion: Interventions that promote gender equality have the potential to increase modern contraceptive use in Nigerian cities.