Adherence and the Economics of Colon Cancer Screening

June 11, 2012 updated by: University of California, San Francisco
This study will compare patient adherence to different colorectal cancer (CRC) screening tests to identify the most cost-effective strategy to decrease mortality from CRC. We hypothesize that different types of tests will have different adherence rates, that these rates will alter the cost-effectiveness analysis, and that we can identify patient variables associated with non-adherence to specific CRC screening strategies.

Study Overview

Status

Completed

Conditions

Detailed Description

Colorectal cancer (CRC) is a significant and preventable disease, yet CRC screening rates remain low. Previous investigators have identified barriers to adherence to CRC screening; however, the majority of data have been retrospectively derived, and the limited data produced from prospective assessment have been limited to fecal occult blood testing (FOBT). Constructs based on the Health Belief Model have been proposed to identify items associated with non-adherence to CRC screening, but prospective validation of this model is lacking. The U.S. Preventive Services Task Force report cites a major cause of uncertainty for calculation of the incremental cost-effectiveness of CRC screening is the deficit in primary data regarding adherence to CRC screening tests, specifically whether heterogeneity exists in screening rates of competing strategies. The Institute of Medicine confirmed the importance of detecting heterogeneity in adherence between strategies, understanding that some strategies currently recommended for CRC screening may be dominated by strategies that achieve greater levels of adherence.

This study aims to determine whether adherence rates to CRC screening are heterogeneous between competing strategies (FOBT and colonoscopy). This study will also prospectively examine domains of the Health Belief Model to identify associations with non-adherence to screening. Adherence rates specific to tested strategies will be incorporated in our existing economic models to compare the incremental cost-effectiveness of competing CRC screening strategies. These data will greatly impact policy decisions regarding resource allocation for CRC screening. It is also expected that future research based on data generated through this project will aim to develop and test interventions that optimize adherence to screening strategies to decrease mortality from CRC.

Procedures:

Patients who are due for CRC screening and meet eligibility requirements are identified through a query of the electronic medical record database at San Francisco General Hospital (SFGH). A research assistant (RA) obtains the PCP's approval to attempt recruitment at the patient's primary care appointment. The PCP discusses CRC screening with the participant during their regularly scheduled appointment.

Availability of CRC screening tests: Because of capacity constraints in the endoscopy unit at SFGH, the screening method for those at average risk of CRC had been limited to annual fecal occult blood testing (FOBT). However, the gastroenterology department initiated a pilot program which allows different primary care clinics to refer average-risk patients for colonoscopy screening in rotating 3-month time-blocks. To ensure the endoscopy unit has sufficient capacity to provide CRC screening via colonoscopy, providers in a given primary care clinic are able to refer their patients for (a) colonoscopy screening, (b) FOBT screening, or (c) a choice of either colonoscopy or FOBT screening, depending on the time block. This is not a study intervention; providers simply recommend that their patients complete a standard CRC screening test, and discuss the option or options available. Patients who decline to participate in the study undergo colorectal cancer screening under the guidance of their primary care provider; the same screening tests are available to those who participate and those who do not.

After giving written informed consent, participants complete an RA-administered 20-minute survey based on constructs of the Health Belief Model. Participants also grant us approval to review their medical records in one year to determine if they complete screening; those without a record of testing are contacted to determine if they completed testing outside of SFGH.

Study Type

Observational

Enrollment (Actual)

1000

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • California
      • San Francisco, California, United States, 94110
        • San Francisco General Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

50 years to 79 years (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

General population of users of outpatient primary care clinics at San Francisco General Hospital at average risk for development of colorectal cancer (CRC). Outpatient clinics include the General Medical Clinic, the Family Health Center, and the Positive Health Program (HIV primary care clinic).

Description

Inclusion Criteria:

  • Average-risk subjects (no family history of CRC, no personal history of polyps or CRC).
  • 50 years of age or greater, but less than 80 years old.
  • Due for CRC screening.
  • Upcoming appointment scheduled with primary care provider.
  • Primary care provider has agreed to refer patients for consideration of enrollment in the study.

Exclusion Criteria:

  • Family history of CRC in a first-degree relative.
  • Personal history of colonic adenomatous polyps, CRC or inflammatory bowel disease.
  • Symptoms for which colonoscopy or sigmoidoscopy would otherwise be performed (hematochezia, new onset diarrhea or constipation, abdominal pain).
  • CRC screening current (FOBT within preceding 12 months, flexible sigmoidoscopy or double contrast barium enema within 5 years, or colonoscopy within 10 years).
  • Comorbid illness precluding endoscopic evaluation (coronary artery disease with myocardial infarction within 6 months, unstable angina or congestive heart failure, chronic obstructive pulmonary disease requiring home oxygen, other diseases that limit life expectancy to less than 10 years).

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Adherence to colorectal cancer (CRC) screening, defined as completion of the screening strategy (the subject agrees to pursue/scheduled by the primary care provider).
Time Frame: one year, and then annually for two more years
Initial adherence measured at one year following enrollment. We have secured additional study funding that will allow us to extend the follow-up period for two more years, so we will measure programmatic adherence to CRC screening strategy over a 3-year period.
one year, and then annually for two more years

Secondary Outcome Measures

Outcome Measure
Time Frame
Preventive Intention: Of those who agree to colonoscopy or FOBT, the proportion of patients who have colonoscopy scheduled or take home FOBT cards.
Time Frame: one year
one year
Preventive Behavior: Of the subjects with a positive FOBT result, determine the proportion adhering to the follow-up colonoscopy.
Time Frame: one year
one year
Identification of variables in the survey (based on the Health Belief Model) which are associated with non-adherence to screening.
Time Frame: one yearone year, and then annually for two more years
one yearone year, and then annually for two more years

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of California, San Francisco

Collaborators

National Cancer Institute (NCI)
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

Investigators

  • Principal Investigator: Hal F Yee, MD, PhD, University of California, San Francisco

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

March 1, 2007

Primary Completion (Actual)

November 1, 2011

Study Completion (Actual)

November 1, 2011

Study Registration Dates

First Submitted

June 24, 2008

First Submitted That Met QC Criteria

June 24, 2008

First Posted (Estimate)

June 26, 2008

Study Record Updates

Last Update Posted (Estimate)

June 12, 2012

Last Update Submitted That Met QC Criteria

June 11, 2012

Last Verified

June 1, 2012

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • A105658
  • R01CA106773 (U.S. NIH Grant/Contract)
  • K24DK080941 (U.S. NIH Grant/Contract)
  • 3R01CA106773-04S1 (U.S. NIH Grant/Contract)

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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