Otolorin, Gbeminiyi R., Castellanos, María Eugenia, Adegboye, Oyelola A., Ratnayake, Himali E., and McBryde, Emma S. (2026) Impact of insecticide-treated nets on malaria morbidity and mortality: a systematic review and meta-analysis of randomized controlled trials. Infectious Diseases. (In Press)

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Abstract

Introduction: This systematic review and meta-analysis examined the efficacy of insecticide-treated nets (ITNs) in reducing malaria incidence and malaria-related mortality among vulnerable populations. Methodology: A comprehensive search of Scopus, Medline, and CINAHL (up-to-April 2, 2026) identified experimental studies (randomised and cluster-randomised trials) evaluating the effect of ITNs impact for malaria control, and the protocol was registered in PROSPERO (CRD42024609183). Pooled-effect-sizes [rate-ratios(RRs) and odds-ratios (ORs)] were calculated, and meta-regression was conducted to examine study-level sources of variation in effect estimates. Results: A total of 25 studies were included in the meta-analysis, including 19 assessing malaria-incidence and 6 evaluating malaria-related mortality. Overall, ITNs demonstrated strong protective effects across diverse populations. The pooled-estimate using a random-effects model showed a 29% reduction in malaria incidence among ITNs users in Africa (RR = 0.71; 95% CI: 0.54–0.93; p = 0.0133; I2 = 64%) and 68% in Asia (RR = 0.32; 95% CI: 0.17–0.62; p = 0.0007; I2 = 89.0%). The pooled-odds-ratio for malaria incidence in African studies indicated a 40% reduction in odds (OR = 0.60; 95% CI: 0.44–0.82; p = 0.0011; I2 = 86.2%), whereas the pooled-rate-ratio for malaria-related-mortality in Asia was 0.82 (95% CI: 0.77–0.89; p 2 = 0) from 5 studies, indicating an 18% reduction in mortality. Meta-regression on 17 studies confirmed an overall significant protective effect of ITNs against malaria(β = −0.84; 95% CI: −1.68 to −0.01; p = 0.05). Conclusion: ITNs reduce malaria transmission, though effectiveness varies across regions due to ecological, epidemiological, and implementation differences.

Item ID:	92684
Item Type:	Article (Research - C1)
ISSN:	2374-4243
Keywords:	cluster randomised controlled trials,insecticide-treated nets,Malaria,malaria control,malaria incidence,randomised controlled trials
Copyright Information:	© 2026 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The terms on which this article has been published allow the posting of the Accepted Manuscript in a repository by the author(s) or with their consent.
Date Deposited:	14 Jul 2026 05:51
FoR Codes:	42 HEALTH SCIENCES > 4203 Health services and systems > 420312 Implementation science and evaluation @ 50% 42 HEALTH SCIENCES > 4202 Epidemiology > 420207 Major global burdens of disease @ 50%
SEO Codes:	20 HEALTH > 2002 Evaluation of health and support services > 200202 Evaluation of health outcomes @ 100%
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