Search engine ads for suicide prevention: analysis of engagement from Indonesia relative to Australia, the USA, and the medical industry standards.

Background: Suicide is a global public health issue, with over 75% of deaths occurring in low- and middle-income countries (LMICs), where access to mental health services is often limited. In Indonesia, where stigma is high and professional support scarce, there is a critical need for scalable, non-traditional approaches to reach individuals at risk. One such approach is using online search engine advertisements to engage individuals searching for suicide-related content and encourage help-seeking. Methods: This study analysed data from an online Google Ads campaign conducted in Indonesia in March 2023, targeting individuals searching for suicide-related keywords. The campaign was co-designed with local experts and people with lived experience. We compared its engagement and cost-effectiveness to similar campaigns previously conducted in the USA and Australia. The primary outcome was total engagement rate (engagements/impressions), and the secondary outcome was effective cost per engagement (adjusted for purchasing power and inflation). Findings: The Indonesian campaign achieved an engagement rate of 11.04%, which was 18 times higher than the US campaign (0.61%) and 15 times higher than the Australian campaign (0.72%). It also had an effective cost per engagement five times lower than those in the USA and Australia. All campaigns outperformed industry standards for health and medical advertising. Interpretation: Search engine advertising is a rapid, cost-effective, and scalable tool to connect individuals in Indonesia with suicide prevention support. These findings underscore the importance of context-specific research in LMICs, where interventions may have greater impact than predicted from high-income country data. Funding: The study was funded by the Australian Department of Foreign Affairs and Trade, Australian-Indonesian Institute (AII2020322), an NHMRC Investigator Grant (GNT2034904), Suicide Prevention Australia Innovation Grant, and the Lynch Family Foundation Research Fellowship in Global Health Equity.