Mortality patterns over a 10-year period in Kibera, an urban informal settlement in Nairobi, Kenya, 2009–2018

ABSTRACT

Background

Reliable mortality data are important for evaluating the impact of health interventions. However, data on mortality patterns among populations living in urban informal settlements are limited.

Objectives

To examine the mortality patterns and trends in an urban informal settlement in Kibera, Nairobi, Kenya,

Methods

Using data from a population-based surveillance platform we estimated overall and cause-specific mortality rates for all age groups using person-year-observation (pyo) denominators and using Poisson regression tested for trends in mortality rates over time. We compared associated mortality rates across groups using incidence rate ratios (IRR). Assignment of probable cause(s) of death was done using the InterVA-4 model.

Results

We registered 1134 deaths from 2009 to 2018, yielding a crude mortality rate of 4.4 (95% Confidence Interval [CI]4.2–4.7) per 1,000 pyo. Males had higher overall mortality rates than females (incidence rate ratio [IRR], 1.44; 95% CI, 1.28–1.62). The highest mortality rate was observed among children aged < 12 months (41.5 per 1,000 pyo; 95% CI 36.6–46.9). All-cause mortality rates among children < 12 months were higher than that of children aged 1–4 years (IRR, 8.5; 95% CI, 6.95–10.35). The overall mortality rate significantly declined over the period, from 6.7 per 1,000 pyo (95% CI, 5.7–7.8) in 2009 to 2.7 (95% CI, 2.0–3.4) per 1,000 pyo in 2018. The most common cause of death was acute respiratory infections (ARI)/pneumonia (18.1%). Among children < 5 years, the ARI/pneumonia deaths rate declined significantly over the study period (5.06 per 1,000 pyo in 2009 to 0.61 per 1,000 pyo in 2018; p = 0.004). Similarly, death due to pulmonary tuberculosis among persons 5 years and above significantly declined (0.98 per 1,000 pyo in 2009 to 0.25 per 1,000 pyo in 2018; p = 0.006).

Conclusions

Overall and some cause-specific mortality rates declined over time, representing important public health successes among this population.

KEYWORDS:

• Mortality rate
• cause of death
• urban informal settlements
• Kibera
• Kenya

Responsible Editor

Maria Nilsson

Responsible Editor

Maria Nilsson

Acknowledgments

The authors wish to thank the residents of Kibera informal settlement for their continued participation in the surveillance. We acknowledge the community leaders for their continued support of the platform since its inception. We would wish also to acknowledge the following individuals for their contributions to this study; The field workers for their dedication in collecting this data, the data team for data management and field supervisors for supervision of field activities. This paper is published with permission from the Director of the Kenya Medical Research Institute.

Author contributions

CO and JRV conceptualised the manuscript. CO analysed, interpreted the data and wrote the first draft. JRV, GB, PM, GA reviewed the first draft and offered substantial revisions. AO, RM, SK, ODM, LC, AA, GSO, DO, RB and JM critically reviewed the manuscript. IO, RM and SK helped with data management and provided field supervision. LC assisted with statistical analysis. All authors read and approved the final version of the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Ethics and consent

Written consent for participation in PBIDS was provided by the household head on behalf of all household members at the time of enrolment. Participation is voluntary and any individual can refuse to participate at any time. The PBIDS protocol and consent procedures, including surveillance and VA activities, were approved by KEMRI (SSC#2761) and CDC Institutional Review Boards (#4566).

Paper context

Despite the sizeable population residing in urban informal settlements in sub-Saharan Africa (SSA) and the unfavourable health conditions therein, limited data are available on rates and causes of mortality in this context. The analysis presented here highlights the mortality patterns and trends within this underserved urban population. We hope that public health experts and policy makers interested in improving health outcomes within urban informal settlements in SSA will find this paper of interest.

Supplementary data

Supplemental data for this article can be accessed online at https://doi.org/10.1080/16549716.2023.2238428.

Additional information

Funding

Funding for this study was provided by the US Centers for Disease Control and Prevention, Division of Global Health Protection, Center for Global Health through various Cooperative agreements with Kenya Medical Research Institute.