Presented at the 2015 American Society of Tropical Medicine and Hygiene (ASTMH) Annual Meeting.

1. Background
Investigating the potential circular effect of mosquito net ownership
on under-five mortality risk in Uganda
Methods
Numerous studies have demonstrated the impacts of mosquito net ownership on mortality risk and there is clear
agreement that mosquito nets are an effective malaria prevention tools(Scenario #1). However, it has been challenging to
quantify the exact effect due to several factors including the lack of data on malaria specific mortality and the possible
circular effect, whereby mortality risk might lead to increase ownership of mosquito nets (Scenario #2). For households
that experience the death of a child under five years of age, it can be a traumatic event that shapes uptake of health
interventions. This study investigated whether this circular effect should be considered when analyzing the impact of
mosquito net ownership on under five mortality risk.
Results
• 2011 Uganda Demographic and Health Survey (DHS)
• Fieldwork: End of June– December 2011
• 3,898 households and 4,036 children included in
analysis (Figure 1)
• A logistic regression was performed to assess whether death is associated with household ownership of
mosquito nets. We hypothesized that households might be more likely to own nets after experiencing a
death event in the household after controlling for other possible covariates.
• Households were retrospectively checked of death in the past 36 months from the date of interview to
assess exposure to the predictor.
• Model adjusted for five covariates: sex of child, household wealth quintiles, area of residence, and region.
All covariates checked for collinearity and interaction.
• Analysis was restricted to households with at least one bed net which was obtained <36 months since the
date of interview.
• Only one child per households without a death included in the model to avoid intra cluster effects.
Conclusion
The results show no association between death event and mosquito net ownership
(OR=0.96, CI: 0.99;0.78), suggesting that a households decision to own a net is not
driven by death. The results suggest that the circular effect is not necessarily
affecting the estimate of mortality risk in relation to mosquito net ownership,
however, this relation should be accounted for.
Acknowledgments
This study was made possible by support from the U.S. Agency for International Development (USAID) under the
terms of Cooperative Agreement GPO-A-00-03-00003-00. The opinions expressed are those of the authors and do
not necessarily reflect the views of USAID, or the United States Government.
Data Source Analysis
Cameron Taylor1, Yazoume Ye2
1DHS Program, ICF International 2MEASURE Evaluation/ICF International,
© 2014 Hannah Koenker, Courtesy of Photoshare
Sample Summary
Variables Odds Ratio (95% CI) p value
Net obtained after death event 0.96 (0.78-0.99) 0.999
Sex
Male ref
Female 1.17 (0.78-1.74) 0.449
Wealth Quintile
Lowest ref
Second 0.99 (0.55-1.78) 0.967
Middle 0.71 (0.39-1.32) 0.277
Fourth 0.74 (0.32-1.70) 0.480
Highest 0.42 (0.18-0.98) 0.045
Residence
Urban ref
Rural 1.12 (0.54-2.28) 0.785
Region
Kampala ref
Central 1 0.62 (0.21-1.82) 0.387
Central 2 1.02 (0.39-2.66) 0.967
East Central 0.99 (0.34-2.88) 0.980
Eastern 0.58 (0.20-1.64) 0.301
North 0.85 (0.22-3.24) 0.812
Karamoja 1.55 (0.52-4.65) 0.429
West-Nile 0.47 (0.15-1.46) 0.192
Western 1.36 (0.52-3.55) 0.529
Southwest 1.19 (0.43-3.29) 0.740
Death of
Child in
Household
Household
Obtains ITN
Unprotected
Household
Household
Obtains ITN
Child Dies
Household
Protected
Scenario #1 Scenario #2
Child Survives
Child lives in household with net
(bed net obtained in the last 36 months)
n=6,192
Child died
n=2,319
Net obtained
after death of child
n=163
Child is alive
n=16,036
Child is alive
(restricted to one child
per household)
n=3,873
Figure 1: Sample Size Diagram
Table 1: Logistic Regression Output
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