CAN IPDAS CRITERIA BE USED TO ASSESS THE QUALITY OF INFORMED CONSENT DOCUMENTS?

Purpose: While informed consent documents serve several purposes, it is becoming clearer that their ability to help potential clinical trial participants in their participation decisions needs to be improved. As part of an ongoing program of research into the role decision aids may play in informed consent, we examined whether the International Patient Decision Aids Standards (IPDAS) might be reliably applied to informed consent documents.  

Method: Forty-seven items of the IPDAS instrument (Elwyn et al, 2009) were initially assessed by the team for applicability to informed consent. Of these, 25 were dropped, and 9 related items added, leaving 31 items. Four raters trained on pilot consent forms, clarifying questions and anchors, until consensus on how to apply the items was achieved. Each item (e.g. “The documents describe the health condition or problem”) was scored on a 4-point scale, from Strongly Disagree to Strongly Agree. For this pilot phase, 10 consent forms randomly selected from the ClinicalTrials.gov website were assessed by all four raters. A pairwise agreement was defined as no more than a 1-point difference between a pair of raters. Descriptive statistics and percent agreement were computed.  

Result: There were 135 disagreements out of a total of 1860 comparisons (6 pairs x 10 consent forms x 31 items), for an overall agreement rate of 92.7%. Item-specific agreement rates ranged from 100% (for 10 of the items) to a low of 61.8% (“The ICDs describe the health condition or problem”). This last item will be split into two questions; agreement for all other items exceeded 80%. Ten of 31 items showed almost no variability in ratings, usually indicating that these issues (e.g. ‘advantages of NOT participating in the study’) are rarely if ever addressed in existing consent forms.  

Conclusion: Application of the IPDAS criteria to informed consent documents can be reliably assessed, and may serve as the foundation for an assessment of the quality of decision making encouraged by consent documents. This exercise highlights important issues to be considered, such as which IPDAS criteria are absent from the existing consent process but might improve decision quality, which criteria are simply beyond the purview of informed consent documents, and whether the focus of consent documents should move away from (barely) informed consent towards good quality participation decisions.