The study results suggest that education increases net-treatment rates. Antecedent education was significantly associated with ITN use at the individual level, but not at the household level. Additionally, knowledge about malaria increased overall for the entire village, but no significant difference was found between education and control groups.
Other studies have found that ITN use increased when individuals received health promotional activities about ITNs [15, 16], although few studies have examined the effects of ITN educational interventions in a control trial. There are several reasons that could explain why a difference was not found at the household level. First, the power of our study to detect differences between intervention and control households may have diminished over time as information diffused from one household to another. In fact, households that were interviewed during the first two days of the study were more likely to impregnate their nets if they received the educational intervention compared to control. Second, simply being in the village may have had an immeasurable influence on net treatment rates. Almost everyone had heard about ITNs previously, but was not using them. Taking time with each individual and/or household to offer net impregnation services from an 'expert' source may have been sufficient to change behaviour. Finally, any ITN use in a household use is a conservative estimate of total ITN use because most households owned more than one net and many people often share a net. Of note, the analysis of ITN use had more power to detect a difference between intervention and control groups, and the effect remained significant after adjusting for within household correlation.
Another important objective of this study was to install net-impregnation services within the village run by community members themselves so that accessibility did not prevent ITN use. A previous study done in Mali demonstrated that individuals who used ITNs were predominantly from communities that had net-treatment services in their village . Other studies have also shown that community involvement is an important factor to the success of net-impregnation programs [12, 17, 18].
Approximately 40% of the village impregnated their nets, which illustrates that availability of services and education can increase ITN use, but there remain substantial barriers to achieving the NMCP goal of 90% use. Cost is clearly a factor as individuals who made a monetary income were more likely to impregnate their nets. Of those who did not impregnate their nets during this study, 93% of individuals said that cost was the main factor. Similar results have been found in other studies [10, 19, 20]. However, the socio-economic data collected in this study suggest that many individuals were able to afford the promotional price of treating one net. Guigemde et al. have shown that treating nets with insecticide is affordable to many individuals in malaria-endemic areas, but they are not aware of how much they spend on other, often less effective, prevention methods . Individuals may also need time to see that impregnation is more effective than untreated nets alone. It was found that more individuals impregnated their nets at later time points during the promotional service once they had seen others benefit from ITN use.
There are limitations to the study. The biggest shortcoming is that the study was done within one village, thus placing control and intervention groups in close proximity. There is a strong possibility that knowledge diffused between individuals who received the educational component and those individuals who did not, as suggested by the fact that almost everyone knew more about malaria after the education intervention. A more rigorous study design would use several widely separated villages rather than households within the same village. However, the limited time and resources precluded identifying and implementing the project in multiple villages with comparable demographic factors.
Second, the field guide who administered the questionnaire and provided the education affected the impact of the education intervention on ITN use, as was demonstrated by the interaction between education and field guide. There is no reason to believe that the educational intervention was delivered differently by each field guide, as both were given the same training and tested on the reproducibility of their presentations. One field guide may simply be a better salesman in promoting net treatment. Regardless of field guide influence, individuals receiving education were still significantly more likely to impregnate their bednets than control group individuals, as shown by the fully adjusted analysis.
Third, there was limited power in this study to detect small effect sizes. The study was planned to have sufficient power to detect a 50% increase in ITN use given the size of the village. The number of households required to detect the effect size observed in this study (400) is larger than the village itself. As mentioned above, resources were not sufficient to include other villages.
Finally, sustainability of net-impregnation program in the long-term was not determined during this study. Although there was not complete ITN use in Piron at the conclusion of the study, increased ITN use may be seen in Piron after the rainy season has finished when malaria transmission is heaviest and the advantages of ITNs are more pronounced. A follow-up study is needed in order to see if this is correct.