Investigation of Medical Management to Prevent Episodes of Diverticulitis Trial (IMPEDE)

Investigation of Medical Management to Prevent Episodes of Diverticulitis (IMPEDE) Trial

This is a randomized trial (n=75) of a Mediterranean style Food Pattern and versus standardized guidance on fiber intake for patients with diverticulitis to evaluate the feasibility of this dietary intervention including willingness to randomize and adherence to a Med-style dietary pattern. The investigators will employ state-of-the-art behavioral interventions in the form of electronic feedback to improve health-related behaviors and support dietary customization based on participants' budget, dietary preferences, and restrictions. The investigators will also examine plasma inflammatory biomarkers (interleukin-6, interleukin-10, and interleukin-1β) and fecal calprotectin at baseline, 6, and 12 months.

Study Overview

• Status: Active, not recruiting
• Conditions: Diverticulitis
• Intervention / Treatment: Behavioral: Medi for All; Dietary supplement: Standard Fiber Supplementation

Detailed Description

This is a feasibility-focused, patient-level randomized trial of an intervention promoting the United States Department of Agriculture (USDA) Healthy Med-Style food pattern versus standardized guidance on fiber intake (standard educational materials related to a high-fiber diet) in patients with a history of diverticulitis. This trial will assess and address barriers to the eventual large-scale trial and lay groundwork for that trial that will focus on the risk of recurrent diverticulitis and other clinical outcomes. The investigators will also compare changes in serum and stool biomarkers of inflammation that are proximal endpoints in the causal path relating a Mediterranean diet pattern's anti-inflammatory properties and recurrence of diverticulitis.

Participants randomized to the USDA Mediterranean-style Food Pattern Arm (called Medi for all) will have access to a "toolbox" that includes education materials (e.g., food pattern tables according to daily caloric intake), recipes, grocery lists, group-based online dietary support, feedback, and reminders to encourage dietary change. Recipes and grocery lists can be individualized to a participant's food budget and preferences. Materials will be available in print and Web-based. This state-of-the art intervention will then use electronic feedback in the form of nudge messages designed to motivate participants to sustain or improve adherence to the Med-style Food Pattern. Every two weeks, participants in the intervention arm will be prompted via a digital online platform (analog also available) to complete the 14-item Mediterranean Diet Assessment Score (MEDAS) (an adapted version of the MEDAS Score previously used in the Prevencion con Dieta Mediterranea [PREDIMED study]) for the purpose of providing timely, individual feedback on diet adherence (not for assessing adherence to the diet pattern). The MEDAS score will be calculated via the online digital platform and ranked according to 3 cutpoints: ≤7, 8-9, or ≥10. Patients will be encouraged to achieve a score of ≥10 which is considered high adherence. The platform will then offer feedback based on the levels of self-reported adherence to the diet including self vs. peer comparisons and support resources. Nudge messages will utilize information from a baseline assessment of participants' dietary attitudes and beliefs about which food groups within a Med-style food pattern they perceive to be most within their control. Ultimately, this approach will enable us to provide participants with dietary information and services that support adherence by accounting for attitudes, norms, and perceived control. The extent of interaction with the online platform will be assessed bi-weekly; degree of adherence to the USDA Med-style food pattern; and engagement in dietician services will be assessed at quarterly intervals.

Participants randomized to the High Fiber Diet Arm will be given commonly used patient education pamphlet, describing fiber and high-fiber foods, the rationale for increasing fiber intake, and ways patients can promote greater intake. Based on prior observational studies of incident diverticulitis, at least 25 grams/day of fiber will be recommended for participants.

• Study Type: Interventional
• Enrollment (Estimated): 75
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Washington
    • Seattle, Washington, United States, 98104
      • Harborview Medical Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Adult ≥18 years;
• Patients presenting (or recently presented) to gastroenterologist or surgeons or accessing study website after recovery from an episode of diverticulitis (within the prior 18 months), either the index episode or recurrent.
• Ability to provide written informed consent in English.

Exclusion Criteria:

• Unable or unwilling to return for specimen collection visits or be contacted for and/or complete research surveys;
• Currently incarcerated in a detention facility or in police custody (patients wearing a monitoring device can be enrolled) at baseline/screening;
• Last episode of acute diverticulitis currently unresolved (i.e., on antibiotics for diverticulitis; drain in place);
• Intolerance/allergy to the main components of the Med-style food pattern;
• Surgery for diverticulitis within past 6 months without an episode of diverticulitis post-surgery;
• Planned elective surgery in next 6 months

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Medi for All; Participants randomized to the USDA Mediterranean-style Food Pattern Arm (called Medi for all) will have access to a "toolbox" that includes education materials (e.g., food pattern tables according to daily caloric intake), recipes, grocery lists, group-based online dietary support, feedback, and reminders to encourage dietary change. Recipes and grocery lists can be individualized to a participant's food budget and preferences. Materials will be available in print and Web-based. This state-of-the art intervention will then use electronic feedback in the form of nudge messages designed to motivate participants to sustain or improve adherence to the Med-style Food Pattern.	Behavioral: Medi for All; Please see description of Medi for All arm
Active Comparator: Fiber Supplementation; Participants randomized to the High Fiber Diet Arm will be given commonly used patient education pamphlet,149 describing fiber and high-fiber foods, the rationale for increasing fiber intake, and ways patients can promote greater intake. Based on prior observational studies of incident diverticulitis, at least 25 grams/day of fiber will be recommended for participants.	Dietary supplement: Standard Fiber Supplementation; Please see description of Fiber Supplementation arm

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Willingness to enroll	Number of randomized participants out of number approached	through study completion, over a period of 2 years
Adherence to Med-Style Food Pattern	Med-style Pattern score calculated from the Nutrition Assessment Shared Resource Food Frequency Questionnaire	through study completion, over a period of 12 months
Participant retention	Proportion enrolled and retained at 3, 6, 9 and 12 months	through study completion, over a period of 12 months
Engagement with nutrition services	Number of sessions with dietician	Quarterly through study completion, over a period of 12 months
Interaction with online program	Number of times accessed	Bi-weekly through study completion, over a period of 12 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Plasma, Interleukin (IL)-6, IL-10, IL-1b, fecal calprotectin	Concentration	Baseline, 6, 12 months through study completion, over a period of 12 months
Diverticulitis events	Self-reported (presumed), subset of those resulting in healthcare utilization (e.g., hospitalization, surgery).	Quarterly through study completion, over a period of 12 months
National Surgical Quality Improvement Program (NSQIP)-defined complications, a subset of which are serious adverse events to be reported to Independent Safety Monitor	Standardized assessment-serious events defined as death, cardiac arrest, myocardial infarction, pneumonia, progressive renal insufficiency, acute renal failure, pulmonary embolism, deep vein thrombosis, return to operating room, serious site infections	Quarterly through study completion, over a period of 12 months
Change in Diverticulitis Quality of Life Survey (DVQOL)	A 17-item questionnaire that assesses four domains: symptoms, concerns, emotions, and behavior changes related to diverticulitis, ranging from 0 (best) to 10 (worst)	Baseline, 6, 12 months
Change in Gastrointestinal Quality of Life Index (GIQLI)	A 36-item questionnaire that assesses five domains: gastrointestinal symptoms, physical function, emotional well-being, social well-being, and perception of medical treatment measured by a single item question. Each item has 5 response choices (i.e., all of the time, most of the time, some of the time, a little of the time, never). In addition, the measure produces an overall QoL score (0-144) where higher numbers indicate greater QoL.	Baseline, 6, 12 months
Change in International Physical Activity Questionnaire (IPAQ) short form	A validated 7-item questionnaire: moderate and vigorous physical activity, walking, and sitting in the past 7 days. Output is self-reported minutes of moderate and vigorous physical activity as well as walking from which weekly moderate and vigorous physical activity, sitting, and walking can be assessed.	Baseline, 6, 12 months
Healthcare utilization	Counts of ED/hospital encounters, diverticulitis-related diagnostic/therapeutic interventions	Quarterly through study completion, at 3, 6, 9, 12 months
Change in self-reported weight	Self-reported weight	Baseline, 6, 12 months

Collaborators and Investigators

• Sponsor: University of Washington
• Collaborators: National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
• Investigators: Principal Investigator: David R Flum, MD, MPH, University of Washington

Study record dates

Study Major Dates

• Study Start (Actual): January 1, 2023
• Primary Completion (Actual): February 1, 2025
• Study Completion (Estimated): February 28, 2026

Study Registration Dates

• First Submitted: November 23, 2022
• First Submitted That Met QC Criteria: December 27, 2022
• First Posted (Actual): January 12, 2023

Study Record Updates

• Last Update Posted (Actual): May 8, 2025
• Last Update Submitted That Met QC Criteria: May 7, 2025
• Last Verified: May 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Diverticular Diseases; Digestive System Diseases; Gastrointestinal Diseases; Gastroenteritis; Diverticulitis
• Other Study ID Numbers: STUDY00015672; 1R01DK131694-01A1 (U.S. NIH Grant/Contract)

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No