Strategies to Increase the Ownership and Use of Insecticide‐Treated Bednets to Prevent Malaria

Abstract

This Campbell systematic review assesses the effectiveness of economic and educational strategies for ownership and appropriate use of insecticide‐treated bednets (‘ITN’) in developing countries. The review also examines whether changes in ITN ownership and use affect malaria‐specific morbidity rates. The review summarises findings from 10 studies, nine of which were conducted in rural Africa and one in rural India. Compared to providing ITNS at full market or a subsidized price, giving away ITNs for free increases the number of people owning an ITN. However, the provision of free ITNs increases their use only slightly or not at all. Providing education in the appropriate use of ITNs increases the number of people sleeping under bednets compared to a control group which didn't receive the education. Combining these strategies with unspecified incentives does not increase ITN ownership, leading to little or no differences in their appropriate use. Embedding the promotion of ITNs within specific health‐ or finance‐focused marketing messages only leads to small or no differences in bednet ownership and use. There is some evidence of improved malaria‐specific morbidities among children and adults as a result of increased ITN ownership and use. However, the evidence supporting this finding is of low certainty and should be interpreted with caution. Plain language summary STRATEGIES TO INCREASE THE OWNERSHIP AND USE OF INSECTICIDE‐TREATED BEDNETS TO PREVENT MALARIA Researchers in the Cochrane and Campbell Collaborations 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 percent 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. Abstract BACKGROUND Malaria is a life‐threatening parasitic disease and 40 percent 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. OBJECTIVES To assess the evidence on the effectiveness of available strategies that focus on delivery and appropriate use of ITNs. SEARCH METHODS 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. SELECTION CRITERIA Randomized controlled trials (RCTs), non‐randomized controlled trials, controlled before‐after (CBA) 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. DATA COLLECTION AND ANALYSIS Two authors independently screened studies to be included. They extracted data from the selected studies and assessed the risk of bias. For RCTs, we used the Cochrane Collaboration's ‘Risk of bias’ tool and we used the risk of bias criteria suggested by EPOC for other study designs. 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. MAIN RESULTS Of the 3,032 possibly relevant records identified, 10 studies were included in this review; eight cluster RCTs, one RCT, and one CBA study. Overall, three studies were assessed as having moderate risk of bias and seven studies were assessed as high risk of bias. Effect of ITN cost on ownership: Four studies including 4,566 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. Pooled data for two studies suggested that receiving an ITN at no cost probably increases ITN ownership, compared to purchasing an ITN at the market price (SMD 0.69, 95% confidence interval (CI) 0.39 to 0.99, moderate‐certainty evidence) or purchasing an ITN using a loan (SMD 0.37, 95% CI 0.27 to 0.47, moderate‐certainty evidence). There is probably little to no difference in ITN ownership when comparing groups in which ITNs were purchased using a loan and those in which ITNs were purchased at the market price (SMD 0.29, 95% CI ‐0.06 to 0.63, moderate‐certainty evidence). Effect of ITN cost on appropriate use of ITNs: Three studies including 9,968 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. Effect of education interventions on use of ITNs: 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. IMPLICATIONS FOR POLICY AND RESEARCH 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 other words, demand for ITNs is elastic with regard to price and hence subsidies (providing full or partial cost recovery) will probably increase ownership. 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. In other words, the evidence suggests that ITN use is highly inelastic with respect to price, and therefore additional encouragement (such as through education) is probably needed to promote appropriate use, over and above any subsidies to increase ownership. However, the impact of different types or intensities of education is unknown.