change that could improve child health. The null results are in line with most of the existing evidence on health promotion campaigns, which typically show that they are ineffective in impacting behavior or that they, at best, enhance the knowledge about the promoted topic. (See, for example, Babor et al.’s work on alcohol prevention campaigns<sup>56</sup> ; Madajewicz et al.’s work on arsenic in water in Bangladesh<sup>57</sup> ; Banerjee and Duflo’s work on vaccination campaigns in Zambia<sup>58</sup> ; and Summerbell et al.’s work on obesity prevention campaigns<sup>59</sup> ).

In contrast, the community intervention, which combined the mass media campaign with more intense training and promotional activities delivered at the district level, proved to be more effective in reaching the targeted audience with the handwashing promotion message, significantly increasing the proportion of mothers and caregivers that reported receiving it. The community treated group reported receiving the message at least through one communication channel more than 15 percent more often than the control group. This more comprehensive treatment seemed to have successfully transmitted the key messages related to handwashing with soap. Increased exposure to the campaign and educational sessions translated into observable learning about best handwashing practices. For example, the proportion of mothers and caregivers that responded correctly that the best method for washing hands is using water and soap increased significantly (around 5 percent) as compared to the control group. Considering the generally good levels of knowledge about this among sample households, this 5 percent change means that almost half the remaining gap in 56 Babor et al. 2003 57 Madajewicz et al. 2007. In this paper, the authors also compared two types of information campaigns and found that the more personalized treatment was more effective. People exposed to a media information campaign obtained as much information as those exposed to a door-to-door campaign, but they did not change their behavior regarding checking whether the dwelling where they obtained water was safe and moving to another dwelling if it was not. The authors also studied a personalized campaign that provided information specific to the individual (whether her/his well is safe and which wells in the vicinity are safe), achieving behavior changes.

58 Banerjee and Duflo (2011) review, among others, the case of Zambia in which a big NGO distributed subsidized chlorine tablets widely, and as a result the campaign informed the population (98 percent identified it as a good way to clean drinking water). However, only 10 percent of families use the tablets. In addition, Banerjee et al. (2010) show that immunization campaigns in rural India are more effective when the poor are given small incentives apart from the vaccines (in this case, lentils and metal plates for completed immunization).

59 Summerbell et al. 2007. Two recent Cochrane reviews on childhood obesity (Campbell et al. 2001; Summerbell et al. 2005) find only modest evidence that diet education impacts the BMIs and consumption habits of schoolchildren, especially in the short term.

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