JMIR Publications

ABSTRACT

Background:

Bladder cancer (BC) is among the most common cancers in the Netherlands and imposes a substantial clinical and economic burden. Evidence from epidemiological studies, indicates that dietary factors are related to BC risk. However, little is known about the potential population-level impact of implementing dietary advice through public campaigns.

Objective:

This study aimed to estimate the potential effect of a national food campaign, dedicated to BC, on dietary behavior, BC incidence, and related healthcare costs using Structured Expert Elicitation (SEE). The maximum impact was explored in a hypothetical scenario under optimistic and idealized assumptions.

Methods:

Relevant food groups were identified based on the 2015 Dutch Dietary Guidelines and BLEND study findings. SEE was conducted among Dutch experts in the field of BC, diet, or public health using a bins-and-chips survey to quantify expected dietary changes following a mass media campaign. A maximum-impact scenario analysis translated estimated dietary changes into hypothetical reductions in BC incidence and associated healthcare costs.

Results:

Fifteen experts (mean experience 21.2 years) participated in the survey. The average expected dietary change across food groups was 5.69%. Relative to the estimated case–non-case dietary intake contrast (15.05%) this corresponds to a potential 12.60% reduction in BC incidence and associated costs. This equates to estimated savings of approximately €14.75 million per year under these hypothetical assumptions.

Conclusions:

This study demonstrates that a public food campaign has the potential to improve dietary habits in the Netherlands. Using a hypothetical maximum-impact scenario, we estimated that dietary changes induced by a public food campaign could translate into substantial reductions in BC–related healthcare costs, while acknowledging that these estimates represent an upper bound rather than a causal effect. Clinical Trial: This study involved structured expert elicitation through a survey. According to the Dutch Medical Research Involving Human Subjects Act (WMO), the study did not fall under the scope of medical scientific research with human subjects as there was no infringement of the physical and/or psychological integrity of the participant and therefore did not require formal ethical approval. All participants provided informed consent prior to participation. Responses were collected and processed anonymously. Participants were informed that they could withdraw from the study at any time without consequences.