DOI: 10.3886/icpsr38590
title: Open Label, Randomized, Multicenter, Comparative Effectiveness Trial of Specific Carbohydrate and Mediterranean Diets to Induce Remission in Patients with Crohn's Disease (DINE-CD), United States, 2017-2020
title: Archival Version

description: The primary aim of this randomized clinical trial is to compare the effectiveness of the Specific Carbohydrate Diet (SCD) and the Mediterranean style diet (MSD) in inducing symptomatic and clinical remission in patients with Crohn's disease. Secondary objectives are to compare the effectiveness of the SCD and MSD in reducing mucosal and systemic inflammation, assessed by measuring the concentration of fecal calprotectin (FCP) and C-reactive protein (CRP) respectively; to compare the diets' effectiveness in improving fatigue, pain, and joint symptoms; and to determine the proportion of patients who continue study diets when prepared food is no longer provided without cost and their reasons for discontinuing the diets. The research aims were guided by crowdsourcing patient-generated research priorities; those that received the most support from Patient-Powered Research Network (PPRN) members were related to diet. Based on the book Breaking the Vicious Cycle (Gottschall 1987), the Specific Carbohydrate Diet (SCD) restricts all but simple carbohydrates. Fresh fruits, vegetables, unprocessed meats, lactose-free cheeses, and certain legumes are permitted; grains, processed foods, canned foods, and milk are not permitted. The Mediterranean style diet (MSD) involves a high intake of olive oil, fruit, nuts, vegetables, and cereals; moderate intake of legumes, fish, seafood, and poultry; and low dairy intake. Red and processed meats, soda drinks, bakery foods, and sweets are not permitted. The MSD was selected as the alternative diet in this trial due to its easier implementation, consistency with U.S. Department of Agriculture and World Health Organization recommendations, and evidence of its role in overall health and specific benefits for Crohn's patients. A total of 194 adult patients with mild to moderate Crohn's disease were enrolled and randomized into either the SCD (intervention) or MSD (control) diet groups at 33 different sites across the United States. Patients received meal delivery for their assigned diet for six weeks, then were provided instructions and recipes to adhere to the diet on their own for weeks seven through twelve. Outcome measures were taken at baseline, six weeks, and twelve weeks.
description: The purpose of the study was to compare the effectiveness of the Specific Carbohydrate Diet (SCD) and a Mediterranean style diet (MSD) in inducing symptomatic and clinical remission in patients with mild to moderate Crohn's disease.
description: A parallel group, randomized trial was conducted in 33 sites across the United States. Enrollment in the trial occurred between September 2017 and October 2019. Potential participants were identified through physician referral, chart review, and the Crohn's and Colitis Foundation of America (CCFA) Partners Patient-Powered Research Network (PPRN), and were referred to a participating center in their region for screening and enrollment. If eligible, baseline data with blood sample were collected in-person following screening and consent procedures. Following nominal eligibility designation, participants were required to complete five to seven days of daily online surveys recording symptoms as measured by the short Crohn's Disease Activity Index (sCDAI) and submit a baseline stool sample in order to be randomized to a treatment group. If accessible, results of the individual's most recent colonoscopy prior to randomization were also collected. To randomize the sample into treatment groups, a computer-generated randomization order stratified by whether the participant was currently receiving therapy with a biologic drug was used to allocate participants in a 1:1 ratio to either the MSD or SCD using random block sizes of 2 and 4. Neither the research team nor the participants were aware of the diet to be assigned next. The SCD was designated the intervention diet, while the MSD was considered the reference or control diet. During the first six weeks of the trial, participants received weekly delivery of prepared meals (breakfast, lunch, dinner, and two snacks per day, minimum 2500 calories) consistent with their assigned diet. During weeks six through twelve, participants were asked to adhere to their assigned diet by preparing or purchasing their own meals and snacks, and were provided with detailed meal planning guidance and recipes. Participants completed daily online surveys to determine sCDAI scores from baseline to week twelve. Diet satisfaction surveys were also completed at weeks three, six, nine, and twelve. In-person visits were completed to evaluate for symptom remission at week six and week twelve, and a final stool sample was submitted. Participants were withdrawn from the study if they experienced worsening symptoms that required a change in their Crohn's disease treatment.
description: The primary outcome variable was symptomatic remission at week six, defined as a sCDAI score of less than 150 with no new Crohn's disease medications started or increased. A secondary outcome was a resolution of inflammation, measured by fecal calprotectin (FCP) response and C-reactive protein (CRP) response. Additional measures included vital signs (at in-person visits), medical history, diet history, prior and current medications, quality of life markers (fatigue, social isolation, pain interference, and sleep disturbance), inflammatory bowel disease symptoms, arthritis symptoms, physical functionality, diet adherence with 24-hour dietary recall, any adverse events that occurred during the course of the study, and patient demographics (age, sex, race, ethnicity).
description: Presence of Common Scales: Short Crohn's Disease Activity Index (sCDAI) and Crohn's Disease Activity Index (CDAI) Inflammatory Bowel Disease Questionnaire (IBDQ) Harvey-Bradshaw Index Bath Ankylosing Spondylitis Functional Index (BAS-FI) Routine Assessment of Patient Index Data (RAPID-3) Rheumatoid Arthritis Disease Activity Index (RADAI) Patient-Reported Outcomes Measurement Information System (PROMIS)
description: Adults with mild to moderate symptoms of Crohn's disease (sCDAI score between 175 and 400) who had internet access were eligible. Individuals were excluded from the study if they were pregnant, hospitalized patients, had used the SCD within four weeks of screening, or were taking certain medications prior to screening. 460 individuals were screened for participation, with 263 failing to meet eligibility criteria and 3 electing not to participate after meeting criteria but prior to diet assignment. 194 participants were randomly assigned to treatment groups, 93 to the MSD and 101 to the SCD. 33 participants withdrew from the study before week 6, and 37 withdrew between weeks 6 and 12. Overall, 63% of participants were women, 91% were White, and 4% were of Hispanic ethnicity.
description: Datasets: DS0: Study-Level Files DS1: Initial Baseline Data DS2: Final Sample Baseline Data DS3: Six Week Follow-Up Survey Data DS4: Outcomes Data DS5: Study Site Data DS6: State FIPS Code Data DS7: Eligibility Survey Data DS8: Study Team Pre-Screening Data DS9: Blood Sample Data DS10: Stool Sample Data DS11: Blood and Stool Analysis Data DS12: Colonoscopy Data DS13: Baseline Short Crohn's Disease Activity Index (sCDAI) Data DS14: Medications Overview Data DS15: Baseline Participant Medications Data DS16: Participant Medication Log Data DS17: Study Registration Survey Data DS18: Randomization Data DS19: Participant Enrollment Data DS20: Participant Visit Type Data DS21: Study Diet Overview Data DS22: Start of Diet Data DS23: End of Diet Data DS24: Diet History Questionnaire (DHQ) Completion Data DS25: Nutrition Survey Completion Data DS26: Diet Satisfaction Survey Data DS27: Harvey-Bradshaw Index (HBI) Data DS28: Inflammatory Bowel Disease Questionnaire (IBDQ) Data DS29: Patient-Reported Outcomes Measurement Information System (PROMIS) Indices Data DS30: Short Crohn's Disease Activity Index (sCDAI) Data DS31: Coupon Usage Data DS32: Common Terminology for Criteria for Adverse Events (CTCAE) Data DS33: Adverse Events Data DS34: Study Termination Data
description: Adults with Crohn's disease having mild to moderate symptoms at the time of enrollment. Smallest Geographic Unit: State
description: face-to-face interview; self-enumerated questionnaire; on-site questionnaire; telephone interview; web-based survey