Association between short birth spacing and child malnutrition in Bangladesh: A propensity score matching approach

Objectives This study aimed to explore the effects of short birth spacing (SBS), which is defined as a period of less than 33 months between two successive births, on multiple concurrent forms of child malnutrition (MCFCM) and at least one form of child malnutrition (ALOFCM) using propensity score matching (PSM). Methods This study used data extracted from the 2017-18 Bangladesh Demographic and Health Survey. PSM with four different distance functions, including logistic regression, classification and regression tree, single hidden layer neural network and random forest, were performed to evaluate the effects of SBS on MCFCM and ALOFCM. We also explored how the effects were modified in different subsamples, including women's empowerment, education and economic status (women's 3E index)-constructed based on women's decision-making autonomy, education level, and wealth index, and age at marriage, and place of residence. Results The prevalence of SBS was 22.16% among the 4652 complete cases. The matched samples of size 2062 generated by PSM showed higher odds of MCFCM (adjusted OR (AOR)=1.25, 95% CI=1.02 to 1.56, p=0.038) and ALOFCM (AOR=1.20, 95% CI=1.01 to 1.42, p=0.045) for the SBS children compared with their counterparts. In the subsample of women with 3E index≥50% coverage, the SBS children showed higher odds of MCFCM (AOR: 1.43, 95% CI=1.03 to 2.00, p=0.041] and ALOFCM (AOR: 1.33, 95% CI=1.02 to 1.74, p=0.036). Higher odds of MCFCM (AOR=1.27, 95% CI=1.02 to 1.58, p=0.036) and ALOFCM (AOR=1.23, 95% CI=1.02 to 1.51, p=0.032) for SBS children than normal children were also evident for the subsample of mothers married at age≤18 years. Conclusion SBS was significantly associated with child malnutrition, and the effect was modified by factors such as women's autonomy and age at marriage.