RADAR Rheumatoid Arthritis Exclusion DietAn Online Randomised Controlled Trial

Amanda Burls1, Amy Price2, Paresh Jobanputra3, Jose Emparanza4

1City University, 2University of Oxford, 3University of Birmingham,4University Hospital Donostia · Clinical Epidemiology and Research

BackgroundAvailable reviews of gluten freediets report low quality evidenceand small studies. Benefits maycome from lower calories or becomplicated by the relapsing/remitting nature of the disease.People with rheumatiod arthritis(RA) are keenly interested in life-style and dietary changes whichmay improve their disease. Alarge randomized controlled trialwith sound methodology andpublic involvement is the best wayto answer the question"Does agluten-free (GF) diet reduce RAsymptoms".

Aims & ObjectivesTo answer the question: Doeseating a GF diet improve thesymptoms of RA? The objectiveof this research is to run a self-recruited randomized onlinepatient preference comprehensivecohort trial in English and Spanishto investigate whether a GF dietimproves the symptoms of active(RA) compared to water or arestricted calorie (RC) diet.

PopulationAdults: normal, overweight andobese with RA.

InterventionsParticipant arms will alter their dietas assigned by the computer for 180 days. Prior to this a 14 dayfeasibility trial will be completed. Aconvenience sample will confirmsymptoms with their physicians.

1. GF participants consume onlygluten-free products caloriesare unrestricted.

2. RC diet calculated as tocaloric needs at present weightand activity levels minus 500calories per day.

3. The control group will drink 8glasses of water.

4. GF and CR combination to testfor interaction

Conditions other than dietary arethe same for all groups.

Outcome Measures● Online BMI Calculator● Printable electronic forms

to record food intake andsymptoms, RAPID3

● Personal weight scale ● PROMIS®

Collaborate ThinkWellHttp://ithinkwell.orgdr.amyprice@gmail.com

Trial DesignOption-1 RADAR is a pragmaticsix-month online RCT factorialdesign to find if there are benefitsof a GF diet for those with activerheumatoid arthritis.

Option-2 If GF efficacy is oversoldin the media we will engagea modified Wennberg design(PLOT-M) and learn to whatextent randomization rather thanchoice influences bias.

Participants are randomized topreference or randomization.Preference participants choosetheir treatment. Controlparticipants are assignedtreatment based onrandomization. All groups areanalyzed to assess the impact ofpatient preference on outcomes.Participants are followed-upin the same way whether theyaccept or reject randomization.A and B will be estimated inthose accepting randomizationfollowed by separate estimatesof A and B in the preferencegroup. Analysis will be based onthese subgroups and all effectsizes will be recorded. PLOT-Menables parallel tracks of a trial torun concurrently, one as patientpreference and the other as anRCT.

Study AnalysisQuantitative methods will be webbased, plus we use qualitative andembedded methods, particpantswill contribute to qualitativeanalysis. Embedded researchwill be a collaborative project withZooniverse and Oxford InternetInstitute.

ReferencesHagen KB, Byfuglien MG, Falzon L, Olsen SU,Smedslund G (2009) Dietary interventions forrheumatoid arthritis. Cochrane Database SystRev 21: CD006400 (2009).Rheumatoid arthritis; National clinical guidelinefor management and treatment in adults.Doi:ISBN 978-1-86016-359-3 (2009)