Comparison of Surgery and Medicine on the Impact of Diverticulitis (COSMID) Trial
COSMID
1 other identifier
interventional
255
1 country
29
Brief Summary
The COSMID (Comparison of Surgery and Medicine on the Impact of Diverticulitis) trial is a pragmatic, patient-level randomized superiority trial of elective colectomy vs. best medical management for patients with quality of life (QoL) limiting diverticular disease. A parallel observational cohort will include those who are disinclined to have their treatment choice randomized, but are willing to contribute information about their outcomes. The goal of the COSMID trial is to answer the question: For patients with QoL-limiting diverticular disease, is elective colectomy more effective than best medical management? The hypothesis being tested in the COSMID trial is that patient-reported outcomes (PROs) among patients in the surgery arm will be superior to those in the best medical management arm.
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at P75+ for not_applicable
Started Oct 2019
Longer than P75 for not_applicable
29 active sites
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
Click on a node to explore related trials.
Study Timeline
Key milestones and dates
First Submitted
Initial submission to the registry
August 28, 2019
CompletedFirst Posted
Study publicly available on registry
September 19, 2019
CompletedStudy Start
First participant enrolled
October 1, 2019
CompletedPrimary Completion
Last participant's last visit for primary outcome
February 1, 2027
ExpectedStudy Completion
Last participant's last visit for all outcomes
February 1, 2027
February 19, 2026
February 1, 2026
7.3 years
August 28, 2019
February 17, 2026
Conditions
Outcome Measures
Primary Outcomes (1)
Patient-reported quality of life as measured by Gastrointestinal Quality of Life Index (GIQLI)
A 36-item questionnaire assessing 5 domains: GI 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 quality of life score (0-144) where higher numbers indicate greater QoL.
Mean GIQLI at 6, 9, and 12 months following randomization to treatment
Secondary Outcomes (4)
Diverticulitis Quality of Life (DV-QoL) instrument
Baseline, 12 months, 24 months
Patient-Reported Outcomes Measurement Information System (PROMIS) Global Health measure
Baseline; 6, 12, 24, 36 months
Decision Regret Scale
6 and 36 months
Work Productivity and Activity Impairment instrument
Baseline; 6, 12, 18, 24, 30, 36 months
Study Arms (2)
Partial Colectomy
ACTIVE COMPARATORElective segmental colectomy for diverticular disease involves removal of the segment of colon (most commonly sigmoid and/or left colon) where there has been disease identified by computed tomography imaging or colonoscopy. Elective colectomy usually removes the affected colon along with adjacent segments that have diverticula, with a primary anastomosis performed to reestablish bowel continuity. Most surgeons now perform the procedure using a laparoscopic approach, when possible, and sometimes use a temporary, protective stoma if the re-connection is considered high-risk. The technique for laparoscopic resection is not specified by the protocol (allows for any number of laparoscopic port sites, all incision types, hand-assistance and robotic) with details of the technique recorded. If randomized to elective colectomy, patients will be encouraged to undergo the procedure within 6 weeks of assignment.
Medical Management
ACTIVE COMPARATORMedical management for diverticular disease has been used for over 30 years and includes a set of interventions, all components of which have been the subject of small, but often positive trials. All patients randomized to medical management or who select it as their treatment in the observational cohort will view a video (provided in English and Spanish) that explains each element of the medical management "toolbox": diet and exercise recommendations, fiber supplementation (e.g., augmenting dietary fiber or over the counter fiber supplements), with mesalazine tablets or suppositories, probiotics and rifamycin. In consultation with their physician, they will be recommended to a regimen of diet and exercise and fiber supplementation. Clinicians will be asked to consider rifamycin (dose/frequency) for those with AUD who are not responding to diet and exercise and mesalazine (dose/frequency) for those with lingering symptoms who are not responding to diet and exercise.
Interventions
Most partial colectomies are performed using a laparoscopic approach, when possible, and surgeons sometimes use a temporary, protective stoma if the re-connection is considered high risk.
Patients will be offered a varying combination of tools from the best medical management "toolbox" (diet and exercise, fiber supplementation/probiotics, and rifamycin/mesalazine) depending on what they have already tried. Based on the "evidence-based best medical toolbox" clinicians will be asked to consider rifamycin (dose/frequency) for those with AUD who are not responding to diet and exercise and mesalazine (dose/frequency) for those with lingering symptoms who are not responding to diet and exercise.
Eligibility Criteria
You may qualify if:
- Adults ≥18 years
- At least one episode of diverticulitis confirmed by CT scan and a colonoscopy (completed or scheduled) to rule out or screen for other colon pathology concordant with screening guidelines
- Persistent signs, symptoms, or concerns related to diverticulitis after recovery from an episode of left-sided diverticulitis as confirmed with self-reported QoL limitation.
You may not qualify if:
- Unable to consent in English or Spanish
- Current diagnosis or previous endoscopic or surgical interventions for fistula, or stricture or current significant bleeding, related to diverticular disease
- Last episode of acute diverticulitis currently unresolved (i.e., on antibiotics for diverticulitis; drain in place)
- Previous operation for diverticulitis
- Right-sided diverticulitis
- Immunodeficiency (e.g., absolute neutrophil count \<500/mm3, chronic immunosuppressive drugs like oral corticosteroids, anti-TNF agents, or known AIDS \[i.e., recent CD4 count \<200\] assessed by patient history)
- Actively undergoing chemotherapy or radiation for malignancy
- Expectant or concurrent hemodialysis, peritoneal dialysis, treatments using indwelling venous catheters, or conditions putting patient at risk for bacterial seeding
- Diagnosis of inflammatory bowel disease (i.e., Crohn's, ulcerative colitis)
- Taking prescription medication for irritable bowel syndrome
- Intolerance or allergy to all medications in the medical management arm
- Comorbid or prior surgical conditions that contraindicate elective surgery (e.g., liver failure, renal failure, malignancy, "frozen abdomen") as determined by surgeon
- Abdominal/pelvic surgery within the past month
- Pregnant or expecting to become pregnant in the 30 days following baseline/screening
- Unable to consent to research or self-respond to follow-up surveys (e.g., altered mental status)
- +3 more criteria
Contact the study team to confirm eligibility.
Sponsors & Collaborators
Study Sites (29)
Cedars-Sinai Medical Center
Los Angeles, California, 90048, United States
UC San Diego Health
San Diego, California, 92103, United States
UCSF Health
San Francisco, California, 94143, United States
Stanford University Medical Center
Stanford, California, 94305, United States
University of Colorado
Denver, Colorado, 80045, United States
University of Florida
Gainesville, Florida, 32608, United States
University of South Florida
Tampa, Florida, 33606, United States
Memorial Health University Medical Center
Savannah, Georgia, 31404, United States
Rush University Medical Center
Chicago, Illinois, 60612, United States
Northwestern University
Evanston, Illinois, 60201, United States
University of Iowa Healthcare
Iowa City, Iowa, 52242, United States
Boston University Medical Center
Boston, Massachusetts, 02118, United States
Lahey Clinic
Burlington, Massachusetts, 01805, United States
Albany Medical College
Albany, New York, 12208, United States
New York Presbyterian-Queens
Flushing, New York, 11355, United States
Columbia University Medical Center
New York, New York, 10027, United States
Weill Cornell Medicine
New York, New York, 10065, United States
University of Rochester Medical Center
Rochester, New York, 14618, United States
Atrium Health-Carolinas Medical Center
Charlotte, North Carolina, 28203, United States
Mount Carmel Health Systems
Columbus, Ohio, 43213, United States
Penn Medicine
Philadelphia, Pennsylvania, 19104, United States
Allegheny-Singer Research Institute
Pittsburgh, Pennsylvania, 15212, United States
Medical University of South Carolina
Charleston, South Carolina, 29425, United States
UT Southwestern Medical Center
Dallas, Texas, 75390, United States
UTHealth Houston
Houston, Texas, 77026, United States
University of Utah Health
Salt Lake City, Utah, 84112, United States
VCU Medical Center
Richmond, Virginia, 23298, United States
Benaroya Research Institute at Virginia Mason
Seattle, Washington, 98101, United States
University of Washington
Seattle, Washington, 98105, United States
Related Publications (1)
Hantouli MN, Schmicker RH, Tufte JE, Ali FG, Bennett RD, Cohan JN, Comstock BA, Curran T, Davidson GH, Eisenstein S, Fischkoff KN, Fleming FJ, Gribovskaja-Rupp I, Jafari MD, Kessler LG, Krane MK, Lawrence SO, McCormick JT, Millas SG, Morris AM, Pullar KM, Reinke CE, Saraidaridis JT, Simianu VV, Watkins SP, White NB, Wick EC, Wieghard N, Flum DR, Read TE; COSMID Collaborative. Comparison of Surgery and Medicine on the Impact of Diverticulitis (COSMID) trial: a protocol for a pragmatic randomised study of diverticulitis treatment in the USA. BMJ Open. 2026 Jan 8;16(1):e098309. doi: 10.1136/bmjopen-2024-098309.
PMID: 41506759DERIVED
MeSH Terms
Conditions
Interventions
Condition Hierarchy (Ancestors)
Intervention Hierarchy (Ancestors)
Study Officials
- PRINCIPAL INVESTIGATOR
David R Flum, MD
University of Washington
Study Design
- Study Type
- interventional
- Phase
- not applicable
- Allocation
- RANDOMIZED
- Masking
- NONE
- Purpose
- TREATMENT
- Intervention Model
- PARALLEL
- Sponsor Type
- OTHER
- Responsible Party
- PRINCIPAL INVESTIGATOR
- PI Title
- Professor, School of Medicine: Surgery
Study Record Dates
First Submitted
August 28, 2019
First Posted
September 19, 2019
Study Start
October 1, 2019
Primary Completion (Estimated)
February 1, 2027
Study Completion (Estimated)
February 1, 2027
Last Updated
February 19, 2026
Record last verified: 2026-02
Data Sharing
- IPD Sharing
- Will share
- Shared Documents
- STUDY PROTOCOL, SAP, ICF
- Time Frame
- We intend to prepare and share a complete, cleaned, de-identified copy of the final dataset used in conducting the final analyses upon which the accepted primary study publication is based, timing dependent on funding. Our goal is that data will be made available no later than the end of the completion of the funded project period for the parent award or once a manuscript (or manuscripts) covering the primary study aims have been published, whichever is earlier. A complete study data set will be permanently archived and available through the PCODR as described above.
- Access Criteria
- Aggregate clinical trials data from all arms of the study will be available in ClinicalTrials.gov, along with related metadata. All other data described above in the "data to be shared" section will be available through the PCODR and preserved through methods which are in accordance with standard practice. There are no anticipated factors or limitations that will affect the access, distribution or reuse of the scientific data generated by the proposal. Data will be shared as allowed by the participant's informed consents and in accord with IRB approval.
Data and results from this proposal stand to develop research that may have a lasting value beyond the term of the award and will be archived and preserved, supporting access to third parties interested in replication and verification of our results and data reuse by other investigators planning future studies. We will prepare and share a complete, cleaned, de-identified copy of the final dataset used in conducting the final analyses upon which the accepted primary study publication is based. The final dataset will include participants' treatment group assignment, demographics and patient reported outcomes (GIQLI survey). Data collected on clinical variables will also include: NSQIP-defined complications major complications, dates and details of healthcare utilization including hospitalizations, length of stay, use of imaging, colectomy details and associated pathology results, and medication use.