Communicating Uncertainty in Written Consumer Health Information to the Public: Parallel-Group, Web-Based Randomized Controlled Trial.

BACKGROUND: Uncertainty is integral to evidence-informed decision making and is of particular importance for preference-sensitive decisions. Communicating uncertainty to patients and the public has long been identified as a goal in the informed and shared decision-making movement. Despite this, there is little quantitative research on how uncertainty in health information is perceived by readers. OBJECTIVE: The aim of this study was to examine the impact of different uncertainty descriptions regarding the evidence for a treatment effect in a written research summary for the public. METHODS: We developed 8 versions of a research summary on a fictitious drug for tinnitus with varying degrees (Q1), sources (Q2), and magnitudes of uncertainty (Q3). We recruited 2099 members of the German public from a web-based research panel. Of these, 1727 fulfilled the inclusion criteria and were randomly presented with one of these research summaries. Randomization was conducted by using a centralized computer with a random number generator. Web-based recruitment and data collection were fully automated. Participants were not aware of the purpose of the study and alternative presentations. We measured the following outcomes: perception of the treatment effectiveness (primary), certainty in the judgement of treatment effectiveness, perception of the body of evidence, text quality, and intended decision. The outcomes were self-assessed. RESULTS: For the primary outcome, we did not find a global effect for Q1 and Q2 (P=.25 and P=.73), but we found a global effect for Q3 (P=.048). Pairwise comparisons showed a weaker perception of treatment effectiveness for the research summary with 3 sources of uncertainty compared to the version with 2 sources of uncertainty (P=.04). Specifically, the proportion of the participants in the group with 3 sources of uncertainty that perceived the drug as possibly beneficial was 9% lower than that of the participants in the group with 2 sources of uncertainty (92/195, 47.2% vs 111/197, 56.3%, respectively). The proportion of the participants in the group with 3 sources of uncertainty that considered the drug to be of unclear benefit was 8% higher than that of the participants in the group with 2 sources of uncertainty (72/195, 36.9% vs 57/197, 28.9%, respectively). However, there was no significant difference compared to the version with 1 source of uncertainty (P=.31). We did not find any meaningful differences between the research summaries for the secondary outcomes. CONCLUSIONS: Communicating even a large magnitude of uncertainty for a treatment effect had little impact on the perceived effectiveness. Efforts to improve public understanding of research are needed to improve the understanding of evidence-based health information. TRIAL REGISTRATION: German Clinical Trials Register DRKS00015911, https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00015911. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR2-10.2196/13425.

Communicating Uncertainty From Limitations in Quality of Evidence to the Public in Written Health Information: Protocol for a Web-Based Randomized Controlled Trial.

BACKGROUND: Uncertainty is integral to evidence-informed decision making and is of particular importance for preference-sensitive decisions. Communicating uncertainty to patients and the public has long been identified as a goal in the informed and shared decision-making movement. Despite this, there is little quantitative research on how uncertainty in health information is perceived by readers. OBJECTIVE: The objective of this study is to design an experiment to examine how different degrees of uncertainty (Q1) and different types of uncertainty (Q2) impact patients' perception of treatment effectiveness, the body of evidence, text quality, and hypothetical treatment intention. The experiment also examines whether there is an additive effect when multiple sources of uncertainty are communicated (Q3). METHODS: We developed 8 variations of a research summary set in a hypothetical scenario for a treatment decision in the context of tinnitus. These were modified only in the degree of uncertainty relating to the evidence of the presented treatment. We recruited members of the German public from a Web-based research panel and randomized them to one of 8 variations of the research summary to examine the 3 research questions. The trial was only open to the members of the research panel. The outcomes are perception of the effectiveness of the treatment (primary), certainty in the judgement of treatment effectiveness, perception of the body of evidence relating to the treatment, text quality, and decisional intention (secondary). Outcomes were self-assessed. We aimed to recruit 1500 participants to the trial. The recruitment and data collection was fully automated. Ethical approval was waivered by an ethics committee because of the negligible risk to participants. RESULTS: This protocol is retrospectively published in its original format. In the meantime, the trial was set up and the data collection was completed. Data collection was conducted in May 2018. A total of 1727 eligible panel members were enrolled. CONCLUSIONS: We aim to publish the results in a peer-reviewed journal by the end of 2019. In addition, results will be presented at conferences and disseminated among developers of guidance for the development of evidence-based health information and decision aids. TRIAL REGISTRATION: German Clinical Trials Register DRKS00015911; https://www.drks.de/drks_web/navigate.do? navigationId=trial.HTML&TRIAL_ID=DRKS00015911 (Archived by WebCite at http://www.webcitation.org/77zyZTGzk). INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/13425.

Quality ratings of reviews in overviews: a comparison of reviews with and without dual (co-)authorship.

BACKGROUND: Previous research shows that many authors of Cochrane overviews were also involved in some of the included systematic reviews (SRs). This type of dual (co-)authorship (DCA) may be a conflict of interest and a potential source of bias. Our objectives were to (1) additionally investigate DCA in non-Cochrane overviews; (2) investigate whether there is an association between DCA and quality assessments of SRs in Cochrane and non-Cochrane overviews. METHODS: We selected a sample of Cochrane (n = 20) and non-Cochrane (n = 78) overviews for analysis. We extracted data on the number of reviews affected by DCA and whether quality assessment of included reviews was conducted independently. Differences in mean quality scores between SRs with and without DCA were calculated in each overview. These differences were standardized (using the standardized mean difference (SMD)) and meta-analyzed using a random effects model. RESULTS: Forty out of 78 non-Cochrane overviews (51%) and 18 out of 20 Cochrane overviews (90%) had included at least one SR with DCA. For Cochrane overviews, a median of 5 [interquartile range (IQR) 2.5 to 7] SRs were affected by DCA (median of included reviews 10). For non-Cochrane overviews a median of 1 [IQR 0 to 2] of the included SRs were affected (median of included reviews 14). The meta-analysis showed a SMD of 0.58 (95% confidence interval (CI) 0.27 to 0.90) indicating higher quality scores in reviews with overlapping authors. The test for subgroup differences shows no evidence of a difference between Cochrane (SMD 0.44; 95% CI 0.07 to 0.81) and non-Cochrane overviews (SMD 0.62; 95% CI 0.06 to 1.17). CONCLUSIONS: Many authors of overviews also often have an authorship on one or more of the underlying reviews. Our analysis shows that, on average, authors of overviews give higher quality ratings to SRs in which they were involved themselves than to other SRs. Conflict of interest is one explanation, but there are several others such as reviewer expertise. Independent and blinded reassessments of the reviews would provide more robust evidence on potential bias arising from DCA.

Words or numbers? Communicating risk of adverse effects in written consumer health information: a systematic review and meta-analysis.

BACKGROUND: Various types of framing can influence risk perceptions, which may have an impact on treatment decisions and adherence. One way of framing is the use of verbal terms in communicating the probabilities of treatment effects. We systematically reviewed the comparative effects of words versus numbers in communicating the probability of adverse effects to consumers in written health information. METHODS: Nine electronic databases were searched up to November 2012. Teams of two reviewers independently assessed studies. INCLUSION CRITERIA: randomised controlled trials; verbal versus numerical presentation; context: written consumer health information. RESULTS: Ten trials were included. Participants perceived probabilities presented in verbal terms as higher than in numeric terms: commonly used verbal descriptors systematically led to an overestimation of the absolute risk of adverse effects (Range of means: 3% - 54%). Numbers also led to an overestimation of probabilities, but the overestimation was smaller (2% - 20%). The difference in means ranged from 3.8% to 45.9%, with all but one comparison showing significant results. Use of numbers increased satisfaction with the information (MD: 0.48 [CI: 0.32 to 0.63], p < 0.00001, I2 = 0%) and likelihood of medication use (MD for very common side effects: 1.45 [CI: 0.78 to 2.11], p = 0.0001, I2 = 68%; MD for common side effects: 0.90 [CI: 0.61 to 1.19], p < 0.00001, I2 = 1%; MD for rare side effects: 0.39 [0.02 to 0.76], p = 0.04, I2 = not applicable). Outcomes were measured on a 6-point Likert scale, suggesting small to moderate effects. CONCLUSIONS: Verbal descriptors including "common", "uncommon" and "rare" lead to an overestimation of the probability of adverse effects compared to numerical information, if used as previously suggested by the European Commission. Numbers result in more accurate estimates and increase satisfaction and likelihood of medication use. Our review suggests that providers of consumer health information should quantify treatment effects numerically. Future research should focus on the impact of personal and contextual factors, use representative samples or be conducted in real life settings, measure behavioral outcomes and address whether benefit information can be described verbally.

Choosing health technology assessment and systematic review topics: the development of priority-setting criteria for patients' and consumers' interests.

BACKGROUND: The Institute for Quality and Efficiency in Health Care (IQWiG) was established in 2003 by the German parliament. Its legislative responsibilities are health technology assessment, mostly to support policy making and reimbursement decisions. It also has a mandate to serve patients' interests directly, by assessing and communicating evidence for the general public. OBJECTIVES: To develop a priority-setting framework based on the interests of patients and the general public. METHODS: A theoretical framework for priority setting from a patient/consumer perspective was developed. The process of development began with a poll to determine level of lay and health professional interest in the conclusions of 124 systematic reviews (194 responses). Data sources to identify patients' and consumers' information needs and interests were identified. RESULTS: IQWiG's theoretical framework encompasses criteria for quality of evidence and interest, as well as being explicit about editorial considerations, including potential for harm. Dimensions of "patient interest" were identified, such as patients' concerns, information seeking, and use. Rather than being a single item capable of measurement by one means, the concept of "patients' interests" requires consideration of data and opinions from various sources. CONCLUSIONS: The best evidence to communicate to patients/consumers is right, relevant and likely to be considered interesting and/or important to the people affected. What is likely to be interesting for the community generally is sufficient evidence for a concrete conclusion, in a common condition. More research is needed on characteristics of information that interest patients and consumers, methods of evaluating the effectiveness of priority setting, and methods to determine priorities for disinvestment.

Long-term effects of weight-reducing diets in hypertensive patients.

BACKGROUND: All major guidelines for antihypertensive therapy recommend weight loss. Thus dietary interventions that aim to reduce body weight might be a useful intervention to reduce blood pressure and adverse cardiovascular events associated with hypertension. OBJECTIVES: Primary objectivesTo assess the long-term effects of weight-reducing diets in hypertensive patients on-   all cause mortality -   cardiovascular morbidity -   adverse events (including total serious adverse events, withdrawal due to adverse events and total non-serious adverse events)Secondary objectivesTo assess the long-term effects of weight-reducing diets in hypertensive patients on-   change from baseline in systolic blood pressure -   change from baseline in diastolic blood pressure -   body weight reduction SEARCH STRATEGY: Studies were obtained from computerised searches of Ovid MEDLINE, EMBASE, CENTRAL and from searches in reference lists and systematic reviews. SELECTION CRITERIA: Randomised controlled trials (RCT) in adult hypertensive patients were included if they had a study duration of at least 24 weeks and compared weight reducing dietary interventions to no dietary intervention in adult patients with primary hypertension. DATA COLLECTION AND ANALYSIS: Two authors independently assessed risk of bias and extracted data. Studies were pooled using fixed-effect meta-analysis. In case of moderate or larger heterogeneity as measured by Higgins I(2), a random effects model was used. MAIN RESULTS: Eight studies involving a total of 2100 participants with high blood pressure and a mean age of 45 to 66 years met our inclusion criteria. Mean treatment duration was 6 to 36 months. No study included mortality as a pre-defined outcome. One RCT evaluated the effects of dietary weight loss on a combined endpoint, consisting of the necessity of reinstating antihypertensive therapy and severe cardiovascular complications. In this RCT weight reducing diet lowered the endpoint, hazard ratio 0.70 (95% confidence interval [CI], 0.57 to 0.87) compared to no diet. None of the studies evaluated adverse events as designated in our protocol. Blood pressure was reduced in patients assigned to weight loss diets as compared to controls: systolic blood pressure (SBP): weighted mean difference (WMD): -4.5 mm Hg; 95% CI, -7.2 to -1.8 mm Hg (3 of  8  studies included in analysis), and diastolic blood pressure (DBP): WMD -3.2 mm Hg; 95% CI, -4.8 to -1.5 mm Hg (3 of  8  studies included in analysis). Patients' body weight was also reduced in dietary weight loss groups as compared to controls, WMD of -4.0 kg (95% CI: -4.8 to -3.2) (5 of  8  studies included in analysis). Two studies used withdrawal of antihypertensive medication as their primary outcome. Even though this was not considered a relevant outcome for this review, the results of these studies strengthen the finding of reduction of blood pressure by dietary weight loss interventions. AUTHORS' CONCLUSIONS: In patients with primary hypertension, weight loss diets reduced body weight and blood pressure, however the magnitude of the effects are uncertain as a result of the small number of patients and studies that could be included in the analyses. It is not known whether weight loss reduces mortality and morbidity. No useful information on adverse effects was reported in the relevant trials.

[Evaluation of an internal guideline for the diagnostics of deep vein thrombosis]. / Evaluation einer abteilungsinternen Leitlinie zur Diagnostik der tiefen Beinvenenthrombose.

BACKGROUND AND PURPOSE: In line with the application of evidence-based medicine as part of the day-to-day clinical practice of a community hospital internal guidelines concerning relevant diagnostic or therapeutic problems were developed. The authors retrospectively compared all data of patients with the tentative diagnosis of deep vein thrombosis (DVT), who underwent further diagnostics before and after implementation of an internally developed guideline for the diagnostics of DVT. The aim was to evaluate if the internal guideline was applied by the doctors in the daily routine and if the implementation led to a change and rationalization of the diagnostic process, in particular with regard to reducing invasive examinations. METHODS: In a retrospective controlled cohort study the medical records of in- and outpatients (n = 371) receiving further diagnostics following a tentative diagnosis of DVT were screened. The kind of examinations, the duration of the diagnostic process and the rate of hospitalization for DVT were compared between the intervention group (n = 185), treated in the initial 10 months following guideline implementation, and the control group (n = 186), treated in the 10 months prior to implementation. Furthermore, the physicians' compliance with the internal guideline was assessed. RESULTS: After implementation in 114 of 185 cases (62%) the treating doctors based their diagnostic procedure on the internal guideline. There was a significant decrease of phlebographies (45.4% vs. 74.2%; RR 0.61 [95% CI 0.51; 0.73]). By contrast, the number of D-dimer tests (81.6% vs. 33.3%; RR 2.45 [95% CI 1.98; 3.03]) and of duplex sonographies (42.2% vs. 21.5%; RR 1.96 [95% CI 1.42; 2.71]) increased significantly. A reduction of the hospitalization rate for further diagnostics of primary ambulant patients (51.3% vs. 60.4% of the tentative cases; RR 0.85 [95% CI 0.69; 1,04]) without a significant change in the final number of DVT diagnoses (33.3% vs. 27.6%; RR 0,83 [95% CI 0,61; 1,13]) was found. There was a slight increment in the mean length of diagnostic process (2.12 vs. 1.84 days). CONCLUSION: The implementation of an internal guideline for the diagnostics of DVT led to a significant reduction of the hospitalization rate and to a considerable change of the diagnostic procedure in favor of noninvasive diagnostic tests, for patients presenting with a diagnosis of suspected DVT.