A realist evaluation of a novel cervical cancer prevention strategy in Iquitos, Peru

Proyecto Precancer is an implementation science and systems-thinking project with the objective of facilitating the adoption of a new screen-and-treat intervention for cervical cancer prevention in Iquitos in the Peruvian Amazon basin. This intervention introduced human papillomavirus molecular testing and shifted treatment from the tertiary level to the primary level through visual assessment for treatment and thermal ablation for those eligible. To inform how we scale up this pilot project to new regions in Peru in collaboration with the Ministry of Health, we conducted this realist evaluation to learn what worked in our pilot intervention in Iquitos, in what circumstances, for whom, and why. We developed four initial program theories, tested them through interviews with 32 stakeholders, we refined the four program theories based on the interviews, and added a fifth theory. This evaluation revealed that continuous engagement with providers in a horizontal manner across the systems' professional hierarchies (Program Theories 1, 4, and 5) and centering patients with a more convenient and accessible continuum of care can, ultimately, lead to improved screening and treatment rates and reduced patient loss to follow-up (Theories 2 and 3). Furthermore, we learned from our collaborators that embedded research within the public health system had high potential for sustainability due to local ownership. These insights will inform our work as this project assists the Ministry of Health in adapting and scaling up the intervention in other parts of Peru.