Nudging Preventive Screening Via Message Framing and Bundling

This study is a randomized controlled field experiment embedded in the medical institution Early Diagnosis Program in Chile. Participants with two exams pending (a cancer screening test and a chronic disease test for diabetes and dyslipidemia) will be randomly assigned across a 3 × 3 factorial design: three message framing conditions (Basic, Risk/Importance, Peace of Mind) crossed with three exam-type conditions (cancer screening only, chronic disease test only, or both exams). Participants with only a cancer screening pending will be assigned to the 3 framing conditions and be encouraged to get the cancer screening. In both cases, participants are assigned to each experimental arm at twice the rate of an additional arm receiving the standard message currently used by the medical institution. This standard-message arm is included for operational purposes, is not part of the pre-specified analyses, and is thus not described in the "Arms and Intervention" section (or counted for "number of arms").

NCT Number	NCT07644910
Lead Sponsor	University of Chile
Conditions	Breast Neoplasms, Uterine Cervical Neoplasms, Colorectal Neoplasms, Prostatic Neoplasms, Diabetes Mellitus, Dyslipidemias
Enrollment	235,000 participants
Start Date	2026-06-08
Primary Completion	2026-09-08 (estimated)
Study Completion	2026-12-08 (estimated)
Updated on ClinicalTrials.gov	2026-06-17