Researchers in the Cochrane Collaboration conducted a review of the effect of different strategies to increase people’s ownership and use of insecticide-treated bednets to prevent malaria. In February 2013 they identified 10 relevant studies. Their findings are summarized below.
What is malaria and how can insecticide-treated bednets prevent it?
Malaria is a life-threatening disease caused by a parasite. A person becomes infected from being bitten by a mosquito carrying the parasite. People with malaria may have symptoms such as chills, fever, vomiting, diarrhea, and jaundice. About 40% of the world’s population is at risk of malaria, mostly in the poorest countries.
Insecticide-treated bednets fit over a bed and act as a barrier between insects and the person sleeping. The bednets are dipped in insecticide, a chemical that kills or repels mosquitoes and effectively prevent malaria. Insecticide-treated bednets cost money and it is important to find ways of ensuring that people who need them own them. Even when people own bednets they may not always use them properly. To be effective, bednets need to be used every night. They must also hang properly and be treated with enough insecticide. It is important to measure whether different strategies not only increase people's ownership but also people's use of bednets.
What this research says:
The studies included in this review took place in Africa and India. In five of the studies, people were either given insecticide-treated bednets free, or could buy them at a subsidized price or full market price. In the other five studies, people were educated about how to use the bednets properly, for instance through visits at home or through information on the radio, on television and in the community. The included studies show the following:
Providing free insecticide-treated bednets:
- Probably increases the number of people who own bednets compared to providing subsidized bednets or bednets offered at full market price.
- Probably leads to little or no difference in the use of bednets compared to providing subsidized bednets or bednets offered at full market price.
Providing education for the appropriate use of insecticide- treated bednets:
- May increase the number of adults and children under five using bednets (sleeping under bednets).
Providing incentives to encourage use of insecticide-treated bednets:
- Probably leads to little or no difference in ownership or use of bednets compared to those who did not receive an incentive.
A possible side effect when providing free or subsidized insecticide-treated bednets may be that the governments and institutions who pay for the bednets take this money from other priority issues. However, none of the included studies measured whether these or any other side effects had occurred.
Five studies examined the effect of price on ITN ownership and found moderate-certainty evidence that ownership was highest among the groups who received the ITN free versus those who purchased the ITN at any cost. In economic terms, this means that demand for ITNs is elastic with regard to price. However, once the ITN is supplied, the price paid for the ITN probably has little to no effect on its use; the four studies addressing this outcome failed to confirm the hypothesis that people who purchase nets will use them more than those who receive them at no cost. Educational interventions for promoting ITN use have an additional positive effect. However, the impact of different types or intensities of education is unknown.
Malaria is a life-threatening parasitic disease and 40% of the world's population lives in areas affected by malaria. Insecticide-treated bednets (ITNs) effectively prevent malaria, however, barriers to their use have been identified.
To assess the evidence on the effectiveness of available strategies that focus on delivery and appropriate use of ITNs.
We searched the EPOC Register of Studies, CENTRAL, MEDLINE, EMBASE, HealthStar, CINAHL, PubMed, Science Citation Index, ProQuest Dissertations and Theses, African Index Medicus (AIM), World Health Organization Library and Information Networks for Knowledge
(WHOLIS), LILACS, Virtual Health Library (VHL), and the World Health Organization Library Information System (WHOLIS). Initial searches were conducted in May 2011, updated in March 2012 and February 2013. Authors contacted organizations and individuals involved in ITN distribution programs or research to identify current initiatives, studies or unpublished data, and searched reference lists of relevant reviews and studies.
Randomized controlled trials, non-randomized controlled trials, controlled before-after studies, and interrupted time series evaluating interventions focused on increasing ITN ownership and use were considered. The populations of interest were individuals in malaria-endemic areas.
Two authors independently screened studies to be included. They extracted data from the selected studies and assessed the risk of bias. When consensus was not reached, any disagreements were discussed with a third author. The magnitude of effect and quality of evidence for each outcome was assessed.
Of the 3032 records identified, 10 studies were included in this review.
Effect of ITN cost on ownership:
Four studies including 4566 households and another study comprising 424 participants evaluated the effect of ITN price on ownership. These studies suggest that providing free ITNs probably increases ITN ownership when compared to subsidized ITNs or ITNs offered at full market price.
Effect of ITN Cost on appropriate use of ITNs:
Three studies including 9968 households and another study comprising 259 individuals found that there is probably little or no difference in the use of ITNs when they are provided free, compared to providing subsidized ITNs or ITNs offered at full market price.
Five studies, including 12,637 households, assessed educational interventions regarding ITN use and concluded that education may increase the number of adults and children using ITNs (sleeping under ITNs) compared to no education.
One study, including 519 households, assessed the effects of providing an incentive (an undisclosed prize) to promote ITN ownership and use, and found that incentives probably lead to little or no difference in ownership or use of ITNs, compared to not receiving an incentive.
None of the included studies reported on adverse effects.