Effect of education on attitude towards domestic violence in Nigeria: an exploration using Propensity score methodology

Abstract

Background: Experimental studies remain the gold standard in making causal inference. However, using experimental studies to estimate the effect of education on attitude towards domestic violence (ATDV) is not feasible due to ethical issues. Propensity Score Methodology (PSM) can be used to overcome this challenge. PSM is a statistical technique used in observational studies to estimate the effect of interventions by accounting for covariates that predicts the treatment. Therefore, PSM was used to investigate the effect of education on ATDV among men and women in Nigeria.Methods: A total of 14,495 and 33,419 records were extracted for men and women respectively from the 2016-2017 Multiple Indicator Cluster Survey (MICS) in Nigeria. The outcome variable was ATDV. The treatment variable was education while the covariates were age, residence, geopolitical zones, marital status, ethnicity, parity, wealth index, alcohol use and media exposure (use of television or radio). For the PSM analyses, selection bias was checked among the levels of education using the multinomial logit regression. Propensity scores (PS) and PS weights were generated for the treatment variable and average treatment effects (ATE) of ATDV were estimated using logistic regression that combined regression adjustment and inverse-probability weighting. Descriptive statistics, odds ratios and 95%CI were presented.Results: The mean age of men and women were 30.8±10.2 years and 29±9.4 years respectively. About 16% men 14% women had tertiary education. The proportion of men and women who justified domestic violence (DV) was 22% and 34.5% respectively. Results from the multinomial logit model showed the existence of selection bias between the covariates and level of education (p<0.05). The selection bias was effectively corrected (SD diff ≈ 0, Variance ratio ≈ 1) after estimation of PS. Results from the PSM showed that the odds of ATDV decreased as level of education increased. Men (AOR = 0.84, 95% CI: 0.78, 0.92) and women (AOR=0.94, 95%CI: 0.80, 2.22) who attained tertiary education were less likely to justify DV in comparison to their uneducated counterparts.Conclusion: Education played a crucial role in ATDV among men and women in Nigeria. Tertiary education was protective for ATDV among men and women. The use of PSM effectively controlled for selection bias in estimating the effect of education on ATDV. PSM will enable researchers make causal inference from non-experimental/ cross-sectional studies in situations where randomized control trials are not feasible.