Study design factors influencing patients’ willingness to participate in clinical research: a randomised vignette-based study

Background: High patient participation in clinical research reduces
selection bias, and ensures the generalisability of study findings. We
explored study-related factors that may influence patients’ willingness to
participate in research. Methods: We submitted by mail two vignettes that
described clinical research studies – a drug trial, and a diagnostic study
– to patients recently discharged from hospital, and assessed Background:
High patient participation in clinical research reduces selection bias,
and ensures the generalisability of study findings. We explored
study-related factors that may influence patients’ willingness to
participate in research. Methods: We submitted by mail two vignettes that
described clinical research studies – a drug trial, and a diagnostic study
– to patients recently discharged from hospital, and assessed their
willingness to participate. We used a factorial design to randomly
allocate three study attributes per vignette: in the drug trial, presumed
superiority of new drug versus equipoise, public versus industry funding,
and random versus non-random treatment allocation; in the diagnostic
study, common versus rare disease, genetic versus protein analysis, and
automatic reporting of results versus reporting on demand. Results: Of
2600 patients contacted, 1140 (44%) participated. Globally, willingness to
participate in a drug trial was lower than in a diagnostic study (44.8%
vs. 76.2%; P <0.001). In the drug trial, participation was
significantly higher when the new drug was presented as presumably better
than the old (vs. equipoise) and when the study was funded by public
sources (vs. industry), but was not affected by the allocation method.
None of the factors tested in the diagnostic study was associated with
participation. Conclusions: Patients were more likely to participate in a
hypothetical observational diagnostic study than in a hypothetical drug
trial. Participation in the trial was lower when clinical equipoise was
expressed, and when the trial was funded by industry. These results
suggest that some features of study design can influence
participation.their willingness to participate. We used a factorial design
to randomly allocate three study attributes per vignette: in the drug
trial, presumed superiority of new drug versus equipoise, public versus
industry funding, and random versus non-random treatment allocation; in
the diagnostic study, common versus rare disease, genetic versus protein
analysis, and automatic reporting of results versus reporting on demand.