What the evidence says
Bed nets are among the most studied interventions in global health. A 2018 Cochrane review pooled five randomized trials with more than 200,000 participants. It found that, compared with no nets, insecticide-treated nets cut child deaths from all causes by about 17 percent, which works out to roughly 5.6 lives saved each year for every 1,000 children protected. The reviewers rated that evidence high-certainty.
Where it sits on the depth scale
Nets are prevention (depth 2): they stop malaria for the people under them, and they keep working only while nets are replaced. They don’t change the conditions that let malaria persist, such as weak health systems or mosquito habitats. That is not a criticism. Prevention at this scale saves lives now, while structural work goes on.
Open questions
- Insecticide resistance in mosquitoes is spreading, and newer nets use different chemicals. How long today’s effect sizes hold is an active research question.
- How nets are used day to day varies by place and season, which is why distribution programs track usage as well as delivery.