Participation in cancer clinical trials: the role of unrealistic optimism and fear of pain (Preprint)
Authors: Chichua Mariam , Filipponi Chiara , Mazzoni Davide , Masiero Marianna , Pravettoni Gabriella 
Published: May 2022

BACKGROUND

In a cancer clinical trial, patients with unrealistic optimism expect to experience higher benefits and lower risks compared to other patients who participate in the same trial. Although this finding has been replicated in few cross-sectional studies, there is no experimental evidence on the relationship between unrealistic optimism and intention to participate in trials.

OBJECTIVE

The aim of the current project is to analyze unrealistic optimism and fear of pain in an experimental design by creating hypothetical scenarios for healthy participants. Specifically, the primary aim is to replicate the effect of unrealistic optimism in an experimental design demonstrating that this bias is only present when considering one's probability to experience higher benefits and lower risks from an event, compared to others who take part in the same event. Second, we aim to investigate how cognitive (unrealistic optimism, perception of control) and emotional (pain) factors may influence the intention to partake in a clinical trial.

METHODS

A between-subject experimental design has been created. 176 participants will be enrolled and randomly assigned to two experimental conditions (N=88 per condition) in which they have to imagine “self” (condition1) or “person X” (condition2) having cancer and being faced with the decision to partake in an early phase clinical trial. Unrealistic optimism and the intention to take part in the clinical trial will be assessed. Other measures will include perceived controllabilityfear of pain.
Corresponding to AIM 1, the two conditions will be compared to see the differences in (1) unrealistic optimism scores and (2) the intention to partake in the clinical trial. Corresponding to AIM 2, the effect of cognitive and emotional factors on the internion to partake in a clinical trial will be tested through a multivariate model.

RESULTS

We expect participants in condition1 to (a) score higher on unrealistic optimism and to (b) have a higher intention to participate. These results would confirm that unrealistic optimism is observed solely when a trial's outcomes are predicted for oneself rather than for another person. Moreover, we expect a significant effect of perceived controllability and of fear of pain on unrealistic optimism and on the intention to take part in the clinical trials.

CONCLUSIONS

This study will provide important insights into the processes that lead people to participate in early phase cancer clinical trials. More specifically, the results will provide useful elements for helping the professionals and patients in the decision-making process, understanding barriers/facilitators in the decision to partake in an early phase clinical trial. Additionally, in respect to previous research, the experimental design gives this study a methodological advantage. By adapting hypothetical scenarios, we hope to encourage other researchers in the field to utilize perspective-taking of healthy participants, alongside studying patients.