title: Comprehension of confidence intervals - development and piloting of patient information materials for people with multiple sclerosis: qualitative study and pilot randomised controlled trial.
abstract: 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.
  
  
  
  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.
  
  
  
  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).
  
  
  
  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.
  
  
  
  German Clinical Trials Register: DRKS00008561 . Registered 8th of June 2015.
authors.affiliation: Institute for Neuroimmunology and Multiple Sclerosis and Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany. Anne.Rahn@uni-hamburg.de.|Unit of Health Sciences and Education, University of Hamburg, Hamburg, Germany. Anne.Rahn@uni-hamburg.de.
authors.forename: Anne C
authors.initials: AC
authors.lastname: Rahn
authors.affiliation: Institute for Neuroimmunology and Multiple Sclerosis and Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Imke
authors.initials: I
authors.lastname: Backhus
authors.affiliation: Unit of Health Sciences and Education, University of Hamburg, Hamburg, Germany.
authors.forename: Franz
authors.initials: F
authors.lastname: Fuest
authors.affiliation: Nursing Research Unit, University of Lübeck, Lübeck, Germany.
authors.forename: Karin
authors.initials: K
authors.lastname: Riemann-Lorenz
authors.affiliation: Nursing Research Unit, University of Lübeck, Lübeck, Germany.
authors.forename: Sascha
authors.initials: S
authors.lastname: Köpke
authors.affiliation: Institut für Didaktik in der Medizin, Michelstadt, Germany.
authors.forename: Adrianus
authors.initials: A
authors.lastname: van de Roemer
authors.affiliation: Unit of Health Sciences and Education, University of Hamburg, Hamburg, Germany.
authors.forename: Ingrid
authors.initials: I
authors.lastname: Mühlhauser
authors.affiliation: Institute for Neuroimmunology and Multiple Sclerosis and Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Heesen
mesh_terms: D000328:Adult; D054626:Consumer Health Information; D005240:Feasibility Studies; D006297:Health Services Accessibility; D006801:Humans; D009103:Multiple Sclerosis; D010353:Patient Education as Topic; D010865:Pilot Projects; D036301:Qualitative Research; D013223:Statistics as Topic
keywords: Confidence interval; Interview; Multiple sclerosis; Patient information; Pilot randomised controlled trial