Discrete-time survival analysis with survey weights: a case study of age at child death in Sierra Leone

Child death rates are often regarded as reliable indicators for overall welfare of a country since they give insight of health accessibility and development. For planning and controlling purposes, it is important to understand which ages are at higher risks of experiencing child death as well as determinants thereof.

We used the Sierra Leone DHS 2019 data which was collected using two stage sampling methods. Data collection involved interviewing women aged from 15-49 to obtain information about children they had in the past up to 2019. Age at death of child was modelled using discrete-time survival analysis with a logit link at the same time applying survey weights. The analysis also sought to estimate the determinants of child death (under-five mortality). The baseline hazard was modelled with a polynomial function.

Results showed that children from rural areas had significantly lower odds of dying compared with those from urban areas (odds ratio (OR) = 0.861, p-value = 0.0003). Children of mothers who were currently using contraceptives, and those whose mothers had been using since their last birth were at higher odds of child death compared to children whose mothers had never used contraceptives before (currently using: OR = 1.118, p-value =  < .0001; used since last birth: OR = 1.372, p-value =  < .0001). Children with no health insurance had significantly higher odds of death than those with health insurance (OR = 1.036, p-value =  < .0001). Children of women who were married, and of women who were formerly married were at significantly higher odds of experiencing child death than children of women who had never been in union (married: OR = 1.207, p-value = 0.0003; formerly married: OR = 1.308, p-value = 0.0009 compared to those that have never been married). Increase in the age group of mothers increases the odds of their children experiencing child death compared to mothers in their teenage years (20-29: OR = 1.943, p-value =  < .0001, 30-39: OR = 2.397, p-value =  < .0001 and >  = 40: OR = 2.895, p-value =  < .0001 compared to mothers in their 15-19 years).

The study provides evidence that residing in urban areas, marital union of the mother, children having no health insurance, use of contraceptives by mother, older ages of the mother and no health insurance significantly increase the odds of child death. This points out to a possible need for improved health infrastructure to be made available to citizens in all places of delivery and more awareness on pregnancy related complications.