LAUSR

Background Although Ethiopia was applauded for achieving the Millennium Development Goal (MDG) target of reducing child mortality, whether the gains sustained beyond the MDG era was rarely studied. In this study, we reported the trends and determinants of under-five mortality (U5M) from 2015 to 2020 in a population based cohort under the Kersa Health and Demographic Surveillance System (HDSS), eastern Ethiopia. Methods We followed pregnant women and their pregnancy outcomes from 2015 to 2020. Each year, data related to death and live births among the follow up population was retrieved. Automated verbal autopsy (InterVA-4) was used to assign the cause of death and Stata 14 was used for analysis. U5M rate was calculated as death among under five children divided by all live births during the study period and described per 1000 live births along with 95% Confidence Interval (CI). A multivariable Cox proportional regression model was used to identify determinant of U5M using adjusted hazard ratio (AHR). Finally, P value <0.05 was considered for declaring statistically significant association. Results From January 2015 to December 2020, a total of 28 870 live births were registered under the Kersa HDSS, of whom 1335 died before their fifth birthday. The overall U5M rate was 46.3 per 1000 live births (95% confidence interval (CI) = 43.79-48.79), with significant increase from 27.9 in 2015 to 54.7 in 2020 (P < 0.041). Diarrheal diseases, acute respiratory tract infection including pneumonia, meningitis and encephalitis, and HIV related deaths were the leading causes of U5M. The hazard of death was higher among children born to poor household (AHR = 1.52; 95% CI = 1.27-1.81), rural residents (AHR = 6.0; 95% CI = 3.65-9.91), born to adolescent mothers (AHR = 1.41; 95% CI = 1.02-1.95), whose mother didn’t receive antenatal care (AHR = 1.43; 95% CI = 1.21-1.69), were born preterm (AHR = 14.1; 95% CI = 9.96-19.89) and had low birth-weight (AHR = 1.74; 95% CI = 1.39-2.18). Conclusion We found high level of U5M rate with an increasing trend in the aftermath of the praised MDG4 achievement. Achieving the ambitious U5M of 25 per 1000 live births by 2030 requires addressing diarrheal disease, and respiratory tract infections, and HIV/AIDS. Reasons behind the persistent increase over the study period require further inquiry.