Background: Clinical trials of patent foramen ovale (PFO) closure for stroke prevention have produced controversial results. We investigated differences in presenting the net benefits of PFO closure or description of the PFO in a randomized vignette-based internet survey.
Methods: Adults aged 18 to 60 inclusive were recruited via Amazon’s Mechanical Turk. Participants read a vignette asking them to imagine that they had a minor stroke. The vignettes included three randomized factors in a 2 x 2 x 3 factorial design: a) benefit of PFO closure (no proven benefit versus ~3% absolute risk reduction, analogous to difference in individual trials versus subsequent meta-analysis); b) normalization intervention (PFO described as very common and benign for most individuals versus no such description); and c) labeling of the PFO (?PFO? versus ?hole in the heart? versus ?difference in heart structure?). Participants were then asked their choice of treatment (PFO closure or aspirin). Secondary outcomes included self-perceived stroke risk and level of anxiety about the PFO diagnosis. Regression analysis was used to assess predictors of treatment choice (logistic) and secondary outcomes (linear).
Results: 2157 participants completed the survey (54.6% female, 76.2% non-Hispanic white, median age 32 with IQR 27 – 41). Participants shown data suggesting 3% absolute risk reduction for PFO closure were more likely to choose PFO closure (30.9% vs. 7.5%, p < 0.001). The normalization intervention decreased anxiety about the PFO. The labeling intervention increased self-perceived stroke risk and had differential effects on patient anxiety (see Table for details).
Conclusion: Differences in how information is presented can influence choice of treatment, perceived stroke risk, and level of anxiety surrounding PFO-associated stroke. Future work should address the impact of information presentation on potential variability in use of PFO closure and patient psychological outcomes.