Can Facebook Ads Save Lives? Exploring the Impact on Malaria Prevention in India

The study by the World Bank and Facebook’s Campaigns for a Healthier World found that social media ads effectively promoted malaria-preventive behaviors among urban, lower-risk populations in India but struggled to reach high-risk, rural communities. Improved targeting strategies could enhance public health impact across diverse demographics.

In a recent study by researchers from the World Bank’s Development Impact Department, Dante Donati, Nandan Rao, Victor Orozco-Olvera, and Ana Maria Muñoz-Boudet explored the potential of social media ads to prevent malaria in high-risk areas of India. Their research, in collaboration with Facebook’s Campaigns for a Healthier World initiative, utilized two field experiments to assess how well digital advertising could influence malaria-preventive behaviors and reduce malaria incidence. The study included a cluster randomized controlled trial across 80 districts in three Indian states, involving more than 8,200 participants and health records to examine the offline effects of a malaria prevention campaign by the public health NGO Malaria No More (MNM). The ads, distributed on Facebook and Instagram, encouraged behaviors like consistent use of mosquito nets and seeking prompt treatment. With the rise of social media as a tool for public health outreach, this research highlights the advantages and challenges of using targeted digital ads for large-scale health campaigns, particularly in reaching diverse demographic groups.

Urban Populations Respond to Malaria Prevention Ads

The campaign delivered ads to boost engagement on Facebook and Instagram, promoting malaria prevention behaviors to over 130 million people in 22 Indian states, covering both urban and rural regions with varying malaria risks. However, the results indicated significant disparities in effectiveness. In urban settings, particularly among individuals living in solid dwellings made of concrete, brick, or stone, the campaign led to promising improvements. In these areas, ad exposure was associated with an 11% increase in bed net use and a 13% boost in the likelihood of seeking treatment quickly if malaria symptoms appeared. The campaign also reported a 44% reduction in self-reported malaria cases, underscoring the campaign’s potential to bring about tangible health benefits among certain demographic groups. Health facility data supported these findings, showing a 30% decline in monthly malaria incidence rates in urban districts targeted by the campaign. However, the results were markedly different for rural populations and households living in non-solid dwellings, often constructed of mud, straw, or tin, where malaria risk remains higher. Among these groups, the campaign showed no significant impact on malaria-related behaviors or reported incidence rates, highlighting a gap in reaching populations most at risk of malaria infection.

Testing for Content Effectiveness Across Demographics

The research aimed to clarify whether the absence of impact in rural areas was due to limitations in ad content effectiveness or the reach of the campaign itself. To investigate further, the researchers conducted a secondary individual-level experiment targeting participants in both solid and non-solid dwellings directly in their Facebook feeds, ensuring that individuals in both types of households received the campaign ads. This experimental exposure revealed that the ads were indeed effective when viewed by people from both dwelling types, leading to an 8% increase in bed net usage and a 2.5% improvement in seeking prompt treatment for those in both solid and non-solid dwellings. This confirmed that the content of the ads was compelling enough to promote malaria-preventive behaviors across different demographics when consistently seen. The researchers concluded that the core issue was not the ad content but the targeting mechanisms used, which tended to prioritize reaching users more easily engaged or more accessible on social media, often bypassing rural, lower-income, and high-risk populations living in non-solid dwellings. Facebook’s algorithmic ad targeting, designed to optimize ad engagement, often reaches urban and wealthier populations more efficiently, making it more challenging and costly to reach people in remote or rural areas where malaria poses a higher threat.

Bridging the Cost of Reaching Vulnerable Populations

This finding has significant implications for social media-based public health campaigns. While digital advertising can be highly cost-effective, delivering targeted messages at scale, its effectiveness is inherently limited by the reach and prioritization choices of ad delivery algorithms. In this study, for example, reaching non-solid dwellers proved to be nearly ten times more expensive than reaching solid dwellers. This discrepancy emphasizes the importance of employing advanced targeting techniques, like Facebook’s Lookalike Audience tool, to ensure that the ads also reach at-risk populations rather than solely focusing on engagement metrics. The study’s findings suggest that the effectiveness of social media campaigns aimed at achieving public health outcomes might be enhanced by customizing strategies that account for varying engagement costs across demographic groups. Moreover, by directly retargeting individuals in high-risk groups, campaigns can balance cost-effectiveness with a greater reach to vulnerable populations.

Evaluating the Cost-Effectiveness of Social Media Interventions

This research offers a new perspective on digital health interventions, illustrating how online campaigns can complement traditional health programs, particularly in urban areas where the cost per averted malaria case was around $3.4. The national campaign costs, at $202,000, equated to averted cases costing roughly between $3.35 and $6.54 each, depending on the regional impact measured. When unreported malaria cases are considered, these costs may be as low as $0.20 per averted case. Compared to conventional malaria interventions like bed net distribution, which generally costs around $5 per averted case, social media campaigns demonstrate high cost-effectiveness, especially for scaling interventions quickly and targeting urban populations. The researchers concluded that although social media ads may not entirely replace on-the-ground efforts, they can enhance them, particularly by promoting behavior change in urban areas and complementing traditional outreach in rural regions. However, for these campaigns to reach their full potential, they must incorporate more sophisticated, equitable targeting strategies that address the limitations of algorithmic prioritization and ensure the most vulnerable populations receive the intended benefits.

Advancing Targeting Strategies for Public Health Success

The researchers’ analysis demonstrated the value of data for targeting users and tracking them to measure ad effectiveness, contributing to the ongoing debate on privacy and the use of third-party data in digital marketing. They propose that by integrating privacy considerations into their experimental methodology, first-party data directly collected from users on social media could help reach the most vulnerable populations in this context, those most at risk of malaria. Ultimately, the study calls for public health campaigns on social media to move beyond traditional ad metrics, focusing on the impact on health behaviors and outcomes among high-risk populations.