Communicating uncertainty from limitations in quality of evidence to the public in written health information: a randomised controlled trial

Article type
Authors
Büchter R1, Betsch C2, Ehrlich M1, Fechtelpeter D1, Grouven U1, Keller S1, Rossmann C2, Waltering A1, Will R1
1Institute for Quality and Efficiency in Health Care
2Institute of Communication and Media Studies, University of Erfurt
Abstract
Background:
Uncertainty is integral to evidence-informed decision-making and of particular relevance to preference-sensitive decisions. While communicating uncertainty to patients and the public has long been identified as a goal in the informed and shared decision-making movement, there is little quantitative research on the issue.

Objectives:
We designed this study to examine how different degrees of uncertainty (Q1) and different types of uncertainty (Q2) impact patients' perception of the effectiveness of a treatment, the body of evidence, text quality and hypothetical treatment decision. We will also examine whether there is an additive effect, when multiple sources of uncertainty are communicated (Q3).

Methods:
We developed a case vignette set in a hypothetical scenario for a treatment decision in the context of tinnitus. The case vignette was manipulated only in the degree of uncertainty (proven effect versus indication of effect), types of uncertainty (small studies versus indirectness versus publication bias) and number of sources of uncertainty relating to the evidence of the presented treatment. Participants will be recruited from an online research panel and randomised to one of eight variations of the case vignette in order to examine the three overarching questions (Q1-3). Outcomes are perception of the effectiveness of the treatment (primary outcome), certainty in the judgement of treatment effectiveness, perception of the body of evidence relating to the treatment, text quality and hypothetical treatment decision (secondary outcomes). Data collection is planned for April 2018.

Patient or healthcare consumer involvement:
The study is being conducted by the Department of Health Information at the Institute for Quality and Efficiency in Health Care (IQWiG) in collaboration with external researchers. The Department has the statutory responsibility to provide the German public with evidence-based health information and decision aids. Various means are used to involve patients and the public in the information development including stakeholder interviews with patient representatives, a review of qualitative experience of illness studies and external user tests of information drafts in focus groups. Experience from many years of providing evidence to the public and explaining uncertainty fed back into the development of this study.