Patients' beliefs regarding informed consent for low-risk pragmatic trials

The requirement to obtain written informed consent may undermine the potential of pragmatic randomized clinical trials (pRCTs) to improve evidence-based care. This requirement could compromise trials statistical power or even force it to close them down prematurely. However, recent data from the U.S. and Spain suggest that a majority of the public endorses written consent for low-risk pRCTs. The present manuscript assesses whether this view is shared by patients.

This was a cross-sectional, probability-based survey, with a 2 × 2 factorial design, assessing support for written informed consent versus verbal consent or general notification for two low-risk pRCTs in hypertension, one comparing 2 drugs with similar risk/benefit profiles and the other comparing the same drug being taken in the morning or at night. This web-based survey was conducted in May 2016. Two-thousand and eight adults who were representative of the Spanish population participated in the survey (response rate: 61%). Of these 2008 respondents, 338 indicated that they had been diagnosed with hypertension and were being treated with prescription medicines for this condition at the time of responding to the survey. The primary outcome measures were respondents' personal preference and recommendation to a research ethics committee regarding the use of written informed consent versus verbal consent or general notification.

Overall, 74% of the 338 patient respondents endorsed written consent. In both scenarios, general notification received significantly more support (30.6%-44.7%) than verbal consent (13.3%-17.6%). 43% of respondents preferred and/or recommended general notification rather than written consent.

As in the survey of the general public, more patients endorsed written consent than the alternative option. However, two factors suggest that a different approach to written consent should be investigated for low-risk pRCTs: a) a substantial minority of respondents supported general notification, b) data from the US have shown that most patients who prefer written consent are willing to forego it if obtaining written consent makes the trial too difficult to be conducted; and c) 2016 CIOMS guidelines endorse waivers of consent when the trial fulfills specific conditions. Surveys in other EU countries are needed to assess what patients believe towards pRCTs. If similar results to that reported in this study are found, it is foreseeable that with educational efforts, general notification could be an acceptable and widespread approach to the conduct of low-risk pRCTs.