When Screening Becomes the Default: How Population-Based Programs Influence Cancer Screening Intentions.

BACKGROUND: Population-based screening programs are widely promoted as a cornerstone of preventive health care, yet their structural features may subtly influence individual decision making. In the present research, we investigated whether informed decision making may be challenged by population-based screening programs if these are perceived as establishing a default of participation. We hypothesized that screening intentions are higher if the screening is part of a population-based program and that this effect is mediated by perceived default. METHODS: In a preregistered online experiment, 997 German participants aged 18 to 75 years (M = 47.93 y, SD = 15.62 y) were randomly assigned to one of three conditions. Participants read a scenario describing a hypothetical cancer screening offered either (a) as part of a population-based screening program, (b) upon request, or (c) within a research project. The main dependent variable was intention to screen. RESULTS: Screening intentions were significantly higher when the screening was included in a population-based program (M = 4.83) compared with a screening that was available upon request (M = 4.42, P = 0.013, d = 0.22, 95% confidence interval [CI] [0.07, 0.37]) or part of a research project (M = 4.44, P = 0.021, d = 0.21, 95% CI [0.06, 0.36]). A mediation analysis revealed that the status of screening indirectly influenced the intention to participate through its effect on the perceived default of participation. CONCLUSIONS: These findings indicate that program structures alone may shape decisions in ways that challenge the aim of informed choice, particularly for screenings with contested benefit-harm profiles. To ensure that population-based programs support rather than undermine informed decision making, communication and program design must promote transparency and enable active, preference-sensitive choices.