Exploring hot spots of short birth intervals and associated factors using a nationally representative survey in Bangladesh

Short Birth Interval (SBI, defined as < 33 months interval between the two most recent births or < 24 months between one live birth to the next pregnancy) is a public health problem in most low- and lower-middle-income countries. Understanding geographic variations in SBI, particularly SBI hot spots and associated factors, may help intervene with tailored programs. This study identified the geographical hot spots of SBI in Bangladesh and the factors associated with them. We analyzed women’s data extracted from the 2017/18 Bangladesh Demographic and Health Survey and the healthcare facility data extracted from the 2017 Service Provision Assessment. SBI was the outcome variable, and it was defined as an interval between consecutive births of 33 months or less, as recommended by the World Health Organization. The characteristics of mothers and their partners were the explanatory variables. Moran’s I was used to examine the spatial variation of SBI in Bangladesh whereas the Getis-Ord Gi∗(d) was used to determine the hot spots of SBI. The Geographical Weighted Regression (GWR) was used to assess the predictors of SBI at the enumeration areas’ level. The variables included in the GWR were selected using the exploratory regression and ordinary least square regression model. Data of 5941 women were included in the analyses. Around 26% of the total births in Bangladesh had occurred in short intervals. A majority of the SBI hot spots were found in the Sylhet division, and almost all SBI cold spots were in the Rajshahi and Khulna divisions. No engagement with formal income-generating activities, high maternal parity, and history of experiencing the death of a child were significantly associated with SBI in the Sylhet division. Women’s age of 34 years or less at the first birth was a protective factor of SBI in the Rajshahi and Khulna divisions. The prevalence of SBI in Bangladesh is highly clustered in the Sylhet division. We recommend introducing tailored reproductive health care services in the hot spots instead of the existing uniform approach across the country.