Predictors of Insecticide-Treated Mosquito Net Use in Malaria-endemic regions; a Meta-analysis

Abstract

University of Washington <bold>Abstract<bold> <bold>Predictors of Insecticide-Treated Mosquito Net Use in Malaria-endemic regions; a Meta-analysis<bold> Saranya Rajagopal Chair of the Supervisory Committee: Professor Ann Duerr Departments of Epidemiology and Global Health <bold>Background<bold>: Malaria remains a leading cause of morbidity and mortality globally. Recommended prevention strategies in the general population include indoor residual spraying and the use of insecticide-treated nets. However, current progress towards the adoption and implementation of these strategies has been slow and several countries lag behind the 2010 Roll Back Malaria Partnership target of 80% uptake. We undertook a systematic literature review and meta-analysis to examine the predictors of net use among the general population in malaria-endemic regions and explore the associations between bed net use and household and individual-level factors. <bold>Methods<bold>: We systematically collected published literature on factors affecting the use of insecticide-treated nets among the general population in malaria-endemic settings. We searched the Global Health Database, Medline, Pubmed, Embase, Web of Science and the Cochrane Database of Systematic Reviews for studies published in English between January 1, 1990, and September 30, 2013, that examined the association between net use and any of the following factors like socioeconomic status, location of residence, knowledge of malaria transmission, education level, gender, age and the number of nets in a household. Adjusted effect estimates were analyzed using random-effects meta-analyses, with sub-group analyses to evaluate potential sources of variability between studies such as study populations, countries, season of data collection and exposure to mass media campaigns. We used funnel plots and Egger's linear regression to test for publication bias. <bold>Findings<bold>: Of 867 articles reviewed, 21 met the inclusion criteria for the meta-analysis. Knowledge of malaria, education level, number of nets in a household and gender were found to be significant predictors of net use in the general population. Household members who had some knowledge of malaria transmission/ITN (versus no knowledge) and households in possession of more nets (compared to those with fewer nets) were the most likely to use an ITN; the summary estimate of the associated OR was 1.47 (95%CI, 1.29 - 1.66) for the knowledge of malaria and 2.35 (95%CI, 1.80 - 3.07) for households with more vs. fewer ITNs. Men were significantly less likely to use an ITN than women (OR, 0.75; 95%CI, 0.69 - 0.82). Not surprisingly, educated individuals were 23% more likely to sleep under a net compared to those with no education (95%CI, 4% - 44%). Pooled summary estimates suggested little or no influence of factors such as socioeconomic status, age and location of residence. However, the effect of age on ITN use varied significantly by study location (p = 0.03); with older age groups significantly more likely to use nets than younger household members in countries such as Malawi and Nigeria. <bold>Conclusions<bold>: Findings from our analysis have significant policy implications particularly for countries reporting wide disparities between ITN ownership and use by households in possession of ITNs. Significant barriers to ownership like socioeconomic status and place of residence were not found to impact net use among households in possession of nets suggesting that factors affecting ITN ownership may differ from those influencing net use. Achievement of the MDG target of universal ITN uptake by 2015 relies on the successful implementation of policies that address barriers to both ITN access and utilization; strategies that solely focus on only one of those components are limited in their potential to reduce malaria burden.