Comparison of Different Frames of Numerical Information in Cochrane Plain Language Summaries

Study Overview
=================
Brief Summary
-----------------
Participants will be randomly given one of two formats containing descriptions of health interventions. In one format, participants will have to read short summaries where results of the intervention are presented as frequencies and the side effects of health intervention are presented as percentages, while in another format the frames will be reversed (results will be presented as percentages and side effects as frequencies). After reading, participants will be asked several questions about the content of the summary and its conclusions.

Official Title
-----------------
Comparison of Different Frames of Numerical Information in Cochrane Plain Language: Randomized Controlled Trial

Conditions
-----------------
Health Knowledge, Attitudes, Practice

Intervention / Treatment
-----------------
* Other: Frequencies
* Other: Percentages


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Patients who are visiting their family doctor, and are at least 18 old. Students of biomedical studies at University of Split School of Medicine, who are at least 18 years old. Exclusion Criteria: Participants younger than 18 years.

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 99 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Frequencies<br> | Other: Frequencies<br>* Results are presented as natural frequencies (e.g. the drug was effective for 1 out of 10 people) while side effects are presented as percentages (e.g. 40% participants experienced severe side effects)<br>|
| Experimental: Percentages<br> | Other: Percentages<br>* Results are presented as percentages (e.g. the drug was effective for 10% of people) while side effects are presented as natural frequencies (e.g. 4 out of 10 participants experienced severe side effects)<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Understanding | Number of the correct answers about the content of the summary, which will consist of four multiple choice questions (with four possible answers where only one is correct, for each question) about the text the participants are reading. Questions will be developed by research team and revised by expert in health communication. The scale ranges from 0-4, where greater score indicates better understanding of the material. | 3 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Attitudes towards the appropriateness of this type of presentation of health information | Likert type scale from 1-10 (1 indicating low appropriateness and 10 would be completely appropriate presentation) | 3 months | 
| Health numeracy | 5 questions about the numerical tasks placed in medical content, total score is number of correct answers on those questions. The five questions are part of Numeracy Understanding in Medicine Instrument (Schapira et al, 2012), and we will translate only the questions focusing on Probability section. Cronbach's alpha in previous research was 0.86 (Schapira et al, 2012). The questions will be revised by independent translator and back translated to English. The scale range is from 0-5, where higher score indicates higher numeracy levels. | 3 months |