ABSTRACT
OBJECTIVES: To evaluate patient information materials on confidence intervals (CIs) in multiple sclerosis to be used with patient decision aids. METHODS: Web-based randomised controlled parallel group trial with four study arms. Participants were equally allocated to one of three versions of audio-visual patient information or to a standard written information (arm IV). In the short version (arm III), CIs were explained without using an example, in the other two versions examples were used (arm I and arm II). The examples are based on an apple farmer who wants to estimate the average weight of his apples (arm I) and to test a treatment against worms (arm II). Primary endpoint was comprehension of CIs, assessed with a six-item multiple-choice questionnaire. RESULTS: 855 of 1068 (80 %) randomised participants completed the survey (71 % arm I, 73 % arm II, 87 % arm III, 90 % arm IV). The median of correctly answered questions on CIs was 4 out of 6 questions in arms I and II and 5 out of 6 questions in arm III. Compared to the standard information (arm IV), all the other arms scored better on the comprehension questionnaire (ANOVA, p ≤ 0.003). CONCLUSIONS: Information about CIs can be presented comprehensibly. High scores and a high rate of completers indicate that the short version is the favourable one. PRACTICE IMPLICATIONS: Information materials on CIs should be used alongside absolute risk reductions in patient decision aids to enhance the interpretation of study results.
Subject(s)
Multiple Sclerosis , Cocos , Comprehension , Confidence Intervals , Humans , Internet , Multiple Sclerosis/therapyABSTRACT
BACKGROUND: Presentation of confidence intervals alongside information about treatment effects can support informed treatment choices in people with multiple sclerosis. We aimed to develop and pilot-test different written patient information materials explaining confidence intervals in people with relapsing-remitting multiple sclerosis. Further, a questionnaire on comprehension of confidence intervals was developed and piloted. METHODS: We developed different patient information versions aiming to explain confidence intervals. We used an illustrative example to test three different approaches: (1) short version, (2) "average weight" version and (3) "worm prophylaxis" version. Interviews were conducted using think-aloud and teach-back approaches to test feasibility and analysed using qualitative content analysis. To assess comprehension of confidence intervals, a six-item multiple choice questionnaire was developed and tested in a pilot randomised controlled trial using the online survey software UNIPARK. Here, the average weight version (intervention group) was tested against a standard patient information version on confidence intervals (control group). People with multiple sclerosis were invited to take part using existing mailing-lists of people with multiple sclerosis in Germany and were randomised using the UNIPARK algorithm. Participants were blinded towards group allocation. Primary endpoint was comprehension of confidence intervals, assessed with the six-item multiple choice questionnaire with six points representing perfect knowledge. RESULTS: Feasibility of the patient information versions was tested with 16 people with multiple sclerosis. For the pilot randomised controlled trial, 64 people with multiple sclerosis were randomised (intervention group: n = 36; control group: n = 28). More questions were answered correctly in the intervention group compared to the control group (mean 4.8 vs 3.8, mean difference 1.1 (95 % CI 0.42-1.69), p = 0.002). The questionnaire's internal consistency was moderate (Cronbach's alpha = 0.56). CONCLUSIONS: The pilot-phase shows promising results concerning acceptability and feasibility. Pilot randomised controlled trial results indicate that the patient information is well understood and that knowledge gain on confidence intervals can be assessed with a set of six questions. TRIAL REGISTRATION: German Clinical Trials Register: DRKS00008561 . Registered 8th of June 2015.
