Prevalence and potential risk factors of short birth interval among reproductive-aged women in Bangladesh: a population-based cross-sectional study

BACKGROUND: Short birth interval is an important reproductive health concern in low- and middle-income countries, including Bangladesh, as it may have adverse consequences for both perinatal and maternal health. According to the International Classification of Diseases, Tenth Revision (ICD-10) codes O09.891, O09.892 and O09.893, pregnancies occurring after a short interpregnancy interval are classified as high-risk pregnancies that require appropriate medical supervision. Understanding the risk factors associated with short birth intervals is crucial for designing effective interventions and achieving the maternal and child health targets outlined in the Sustainable Development Goals. Therefore, this study aimed to investigate the prevalence and identify the potential risk factors of short birth interval using a two-level logistic regression (LR) model and the Boruta machine learning (ML) based feature selection method. DESIGN: This was a cross-sectional study. SETTING: The study used secondary data from the nationally representative Bangladesh Demographic and Health Survey (BDHS) 2022. PARTICIPANTS: The study included 11 872 married women of reproductive age (15-49 years) in Bangladesh who reported at least one previous live birth. The demographic, socioeconomic, reproductive and media exposure-related characteristics of the study participants were obtained from the BDHS 2022 dataset. METHODS: A two-level LR model was used to identify the risk factors associated with short birth interval, and the results were presented as adjusted ORs (aORs) with 95% CIs and p values