Pre- and during -COVID-19 pandemic mortality trends and drivers in rural, coastal Kenya: findings from the Kaloleni–Rabai Health and Demographic Surveillance System

Background: There is contradicting information regarding the effect of COVID-19 on mortality in African settings. Knowledge of the complete direct and indirect burden of COVID-19 on mortality is heavily reliant on the availability of a population-based surveillance system. Here we provide robust data on the effect of COVID-19 on mortality trends in a rural, coastal, Kenyan community. Methods: A historical cohort study using data from the Kaloleni Rabai Health and Demographic Surveillance System was conducted with special focus on two discernible time periods representing the pre-COVID-19 (2018–2019) and COVID-19 (2020–2021) periods. Mortality rates were estimated as the total number of deaths divided by the person-time (years) at risk, accounting for attrition, and calculated separately for the two periods. A cox proportional hazards model was used to estimate the impact of COVID-19 on mortality. Results: 1191 deaths occurred between 2018 and 2021. There was no significant change in overall mortality rates between pre-COVID-19 and COVID-19 periods (3.7 and 3.6 per 1000 person years at risk respectively, p = 0.74). Older age was significantly associated with mortality (a_HR: 1.05, 95% CI: 1.05–1.06; p < 0.001). However, an interaction term between age and time-period appeared to reverse this association (a_HR: 0.99, 95% CI: 0.99–1.00; p < 0.001). Conclusions: Our findings suggest that although overall COVID-19 did not directly impact mortality rates within this rural population, the onset of the pandemic did appear to reverse and/or attenuate the impact of several risk factors on mortality. It is possible that COVID-19 brought health and wellness into sharp focus, making people more vigilant about their health, hygiene and associated preventive measures.