Full Title: National Institutes of Health (NIH) State-of-the-Science Conference: Enhancing Use and Quality of Colorectal Cancer Screening
Expected Release Date: late 2009
Contents
Background and Objectives for the Systematic Review
Key Questions
Analytic Framework
Methods
References
Definition of Terms
Summary of Protocol Amendments
Review of Key Questions
Technical Expert Panel (TEP)
Peer Review (Standard Language)
Appendix A
Appendix B
I. Background and Objectives for the Systematic Review
Background
Colorectal cancer is the third most commonly diagnosed cancer and the third leading cause of cancer death in both men and women in the United States. The American Cancer Society (ACS) estimates that in 2008, slightly less than 150,000 people were diagnosed with colorectal cancer and approximately 50,000 will have died from the disease (ACS, 2008). Colorectal cancer is one of the few cancers where many cases can be detected early through screening so that death is prevented. While national guidelines from organizations like ACS and the United States Preventive Services Task Force (USPSTF) do not consistently agree on which tests should be administered when, and to whom, they generally agree that annual colorectal cancer screening by a fecal occult blood test (FOBT) performed at home among average-risk people 50 years of age or older is recommended, and either a flexible sigmoidoscopy every 5 years or a colonoscopy every 10 years (USPSTF, 2008). However, despite evidence and guidelines supporting the value of screening for this disease, only a small proportion of Americans report adequate screening. In National Health Interview Survey (NHIS) responses from 2005, 12.1 percent of adults aged 50 or older used an FOBT at home in the past year, 43.1 percent had an endoscopy exam (i.e., either a flexible sigmoidoscopy or colonoscopy in the recommended timeframes), and 46.8 percent had either an FOBT in the past year, sigmoidoscopy in the past 5 years, or colonoscopy in the past 10 years (CDC, 2006). Unfortunately, rates of screening for colorectal cancer are consistently lower than those for other types of cancer, particularly breast and cervical (ACS, 2008).
A number of factors contribute to the low rates of colorectal cancer screening. Unlike most other preventive services, there are several tests for colorectal cancer screening and the introduction of new test modalities such as fecal immunochemical testing (FIT) and virtual colonoscopy/computed tomography (CT) colonography further increases the available options. Choosing the best screening test option can be complicated. Tests vary in their complexity, invasiveness, and availability. Screening methods also differ considerably in cost. Recent data provided by ACS estimates that the costs of colorectal screening tests can range from less than $30 for the FOBT to $1,000 or more for a colonoscopy (ACS, 2008). A small but growing body of literature suggests that both physicians and patients have preferences for various characteristics of colorectal cancer screening tests that influence whether and how screening is accomplished (Pignone, et al., 1999; Coughlin and Thompson, 2004; Klabunde, et al., 2007; Schroy & Heeren, 2003). Ideally, patients and providers should choose the test that is most appropriate for and acceptable to the patient (Pignone et al., 2000).
Making things even more complex, there is concern that colorectal cancer screening may also be overused in certain situations (Sawaya, et al., 2007). Although people under 50 years of age are at lower risk of colorectal cancer, and although the reduced life expectancy of people over age 75 means that they will benefit less from screening, people in both of these groups are being screened. In addition, people undergoing sigmoidoscopy or colonoscopy most frequently have all polyps removed, despite the increased risk of complications such as colonic perforation or bleeding, and despite the uncertainty of the benefit from removing small polyps. Finally, surveillance of people who have had benign polyps removed is sometimes more frequent than evidence supports (Pignone, et al., 2002). Thus, the quality of screening, in terms of underuse, overuse, and misuse, is suspect.
Objectives and Topic Nominator/Partner Information
The Agency for Healthcare Research and Quality (AHRQ), on behalf of the Office of Medical Applications Research (OMAR) located in the Office of the Director of the National Institutes of Health (NIH), has requested an evidence report on enhancing the use and quality of colorectal cancer screening. The report will be based on a comprehensive and systematic review of the scientific literature, other appropriate analyses, and extensive peer review of the draft report. Both the report and a corresponding NIH state of the science (SoS) conference are a part of the NIH Consensus Development Program (CDP). The purpose of the CDP is to evaluate the scientific evidence on a particular topic and develop a statement that advances research in this area. The statement is created by an independent panel that is assembled for the conference. The panel will hear the scientific data, including information from the evidence report, and then will use this information to compose their statement.
The NIH State-of-the-Science Conference, Enhancing Use and Quality of Colorectal Cancer Screening, and corresponding report will provide a comprehensive assessment of how colorectal cancer screening is implemented, monitored, and evaluated for average-risk populations in the United States. Findings will identify knowledge and system gaps that need to be addressed in order to increase the appropriate use and quality of colorectal cancer screening.
In the case of reports generated for conferences sponsored by OMAR, the partner(s) are OMAR and the Conference Panel Chairperson. An Evidence-based Practice Center (EPC) is selected through a competitive process to conduct the systematic review and develop the report. Experts from fields related to colorectal cancer screening have been asked to serve as members of a Technical Expert Panel (TEP) and include experts in gastroenterology, primary care, patient advocacy, and health behavior research, as well as the Conference Panel Chairperson. TEP input will help guide the systematic review of the literature, which the EPC will use to draft a report for the conference.
Additional information about the NIH Consensus Development Program (CDP) can be found at: http://consensus.nih.gov/ABOUTCDP.htm.
Project Start Date: 12/01/2008
Anticipated Draft Report Due Date: 09/01/2009
Anticipated Report Publication Date: 11/25/2009
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II. Key Questions
Exhibit 2-1 provides five key questions (KQs) along with key words developed by the OMAR Planning Committee that will be used to guide the systematic review. A sixth key question ("What research is needed to make the most progress and have the greatest public health impact in promoting the appropriate use of colorectal cancer screening?") is a derivative of the other five key questions and will not have a separate literature search.
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III. Analytic Framework
Based on the key questions, we developed an analytic framework to guide the systematic review (Exhibit 3-1). We now present a figure in Exhibit 3-1, "Analytic Framework for the Colorectal Cancer Screening Systematic Review," that depicts how we believe various factors interact to impact the appropriate use of screening tests. This exhibit is described in the following paragraphs.
Specifically, both KQ 1, which pertains to trends in use and quality of colorectal cancer screening, and KQ 5, which pertains to monitoring the use and quality, are considered to be outcomes of the process depicted in Exhibit 3-1. During the systematic review, we will make assessments of the changes in trends over time and of how the use and quality of the specific tests (i.e., colonoscopy, sigmoidoscopy, CT colonography, and stool tests) are monitored. This will include paying particular attention to such issues as the extent to which overutilization and/or underutilization of tests is evident (Seeff et al., 2004; Pollack et al., 2006), how the quality of these tests is assessed, and other issues noted in Exhibit 2-1.
Exhibit 3-1. Analytic Framework for the Colorectal Cancer Screening Systematic Review
Many factors have been shown in the literature to influence both the use and quality of tests. While the patient is ultimately the one to make the decision about whether to obtain screening (Schroy & Heeren, 2003), this decision is directly impacted by a discussion with the health care provider about screening needs and options (Klabunde et al., 2007; Sheridan, Harris, & Woolf, 2004). This discussion is depicted in the analytic framework as the point at which an interaction between key patient and provider characteristics occurs to guide the discussion. As shown in the two boxes on the far left of the analytic framework (Exhibit 3-1), both the patient and the provider bring characteristics to this interaction that are immutable yet likely to impact the provider's recommendations for colorectal cancer screening and the patient's ultimate decision to seek screening. Termed "predisposing" by Green and Kreuter, these factors exert their effects prior to a behavior occurring, by increasing or decreasing a person's or a population's motivation to undertake that particular behavior (2004).
Predisposing patient characteristics that may influence the ultimate decision related to colorectal cancer screening include:
- Family history of colorectal cancer.
- Perceived risk or understanding of whether they are likely to be diagnosed with colorectal cancer.
- Education level, income, and other socioeconomic factors (Slattery, Kinney, & Levin, 2004).
- Location of residence (i.e., proximity to screening facilities and/or providers) (Coughlin & Thompson, 2004).
Predisposing physician characteristics that have been shown to influence screening recommendations (Klabunde et al., 2007; Subramanian et al., 2004) include:
- Perceived effectiveness of each type of colorectal screening test.
- Physician demographic characteristics such as age, whether solo or group practice, and location of practice.
- Medical training and awareness of current screening guidelines.
These and other factors will be derived from the literature to address KQ 2. In addition, interventions have been developed (KQ 3) to address patient and/or provider characteristics to increase colorectal cancer screening; these interventions will be incorporated into the literature search. Other types of interventions have been designed to act as "cues to action" for the patient (Becker, 1974) and might include community-based interventions to enhance awareness about the need for screening (Greenwald, 2006), or to otherwise increase screening rates. These interventions will be incorporated into the search, with a focus on those that measure their impact on the outcome of screening behavior, not on increasing awareness or intentions to screen. Throughout this process of deciding to seek screening and obtaining the test, factors associated with the health care system will impact the ultimate screening behavior. These factors include those related to KQ 2 (e.g., insurance status of the patient and copayments required by their carrier [if they have one], reimbursement rates the provider will receive for different types of tests) and are specific to the local capacity for tests (KQ 4).
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IV. Methods
A. Criteria for Inclusion/Exclusion of Studies in the Review
Exhibit 4-1 presents the inclusion/exclusion criteria we will use during abstract and full test review.
B. Searching for the Evidence: Literature Search Strategies for Identification of Relevant Studies to Answer the Key Questions
We will systematically search, review, and analyze the scientific evidence for each key question and any subsidiary questions. The steps that we will take to accomplish the literature review are described below.
To identify articles relevant to each key question, we began with a focused MEDLINE® search on colorectal cancer screening tests using a variety of terms, MeSH and major headings, limited to English and human-only studies. We also searched other databases (The Cochrane Library and the Cochrane Central Trials Registry). Results from initial database searches are presented in Exhibit 4-2.
Our initial searches yielded 2,544 citations across databases. We will review our search strategy with the TEP and supplement it as needed according to their recommendations. In addition, to attempt to avoid retrieval bias, we will manually search the reference lists of landmark studies and background articles on this topic to look for any relevant citations that might have been missed by electronic searches. We will also conduct an updated literature search (in MEDLINE®, the Cochrane Library, and the Cochrane Central Trials Registry) before completing the final draft of the report. We do not anticipate incorporating gray literature in this search.
C. Data Abstraction and Data Management
We will review all titles and abstracts identified through searches against our inclusion/exclusion criteria. Each abstract will be independently reviewed by two members of the team. When differences between the reviewers arise, we will include studies for full-text review. For studies without adequate information to make the determination, we will again review the full text. All results will be tracked in an EndNote database.
We will retrieve the full text of all titles included during abstract review. Each full-text article will be independently reviewed by two members of the team for inclusion or exclusion based on the eligibility criteria described above. If both reviewers agree that a study does not meet the eligibility criteria, the study will be excluded. If the reviewers disagree, conflicts will be resolved by discussion and consensus or by consulting a third, independent party. As above, all results will be tracked in an EndNote database including, where applicable, the reason a study did not satisfy eligibility criteria so that we can later compile a listing of excluded articles and reasons for such exclusions.
We will design data collection forms that include questions on identifying information for the article, study design, methods, and results. Trained abstractors will extract the relevant data from each included article into preformatted tables. Data abstractions will be reviewed for accuracy by a second member of the team.
D. Assessment of Methodological Quality of Individual Studies
To assess the quality (internal validity) of studies, we will use predefined criteria based on those developed by the US Preventive Services Task Force (ratings: good, fair, poor) and the National Health Service Centre for Reviews and Dissemination. In general terms, a "good" study has the least bias and results are considered to be valid. A "fair" study is susceptible to some bias but probably not sufficient to invalidate its results. A "poor" rating indicates significant bias (e.g., stemming from serious errors in design or analysis) that may invalidate the study's results. To assess the quality of observational studies, we will use criteria outlined by Deeks, et al. (2003).
Two independent reviewers will assign quality ratings to each study. Disagreements will be resolved by discussion and consensus or by consulting a third, independent party.
E. Data Synthesis
We anticipate that the data found from the literature review will be synthesized qualitatively. However, if we find a sufficient number (three or more) of similar studies of factors influencing the use of colorectal cancer screening or of interventions to increase the appropriate use of colorectal cancer screening, we will consider quantitative analysis (meta-analysis) of data from those studies.
F. Grading the Evidence for Each Key Question
We will rate the strength of evidence based on the standard methods of the EPCs, which use a revised version of the approach devised by the GRADE working group (Atkins et al. 2004). Developed to grade the quality of evidence and the strength of recommendations, this approach incorporates the following elements: study design, study quality, consistency, directness, presence of imprecise or sparse data, high probability of publication bias, and magnitude of the effect. We use four grades: high, moderate, low, and insufficient.
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V. References
An initial list of key authors and citations cited in this report appears in Appendix B. More will be added as the approach to the systematic review is refined.
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VI. Definition of Terms
The terms "use" and "quality" are included in two of the key questions and need to be defined consistently in order to conduct the systematic review. Appendix A provides draft indicators and definitions for these terms.
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VII. Summary of Protocol Amendments
In the event of protocol amendments, the date of each amendment will be accompanied by a description of the change and the rationale.
Note: The following protocol elements are standard procedures for all protocols.
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VIII. Review of Key Questions
Key questions submitted by partners are reviewed and refined as needed by the EPC and the TEP to assure that the questions are specific and explicit about what information is being reviewed.
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IX. Technical Expert Panel (TEP)
A TEP is selected to provide broad expertise and perspectives specific to the topic under development. Divergent and conflicted opinions are common and perceived as healthy scientific discourse that results in a thoughtful, relevant systematic review. Therefore, study questions, design, and/or methodological approaches do not necessarily represent the views of individual technical and content experts. The TEP provides information to the EPC to identify literature search strategies, reviews the draft report, and recommends approaches to specific issues as requested by the EPC. The TEP does not do analysis of any kind nor contribute to the writing of the report. In the case of reports generated for conferences sponsored by OMAR, the Conference Panel Chairperson will also serve as a member of the TEP.
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X. Peer Review (Standard Language)
Approximately five experts in the field will be asked to peer review the draft report and provide comments. The peer reviewer may represent stakeholder groups such as professional or advocacy organizations with knowledge of the topic. Peer review comments on the preliminary draft of the report are considered by the EPC in preparation of the final draft of the report. The synthesis of the scientific literature presented in the final report does not necessarily represent the views of individual reviewers. It is our policy not to release the names of the peer reviewers or TEP panel members until the report is published so that they can maintain their objectivity during the review process.
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Current as of May 2009
Internet Citation:
Enhancing Use and Quality of Colorectal Cancer Screening, Systematic Review Protocol. Agency for Healthcare Research and Quality, Rockville, MD. http://www.ahrq.gov/clinic/tp/crcprotp.htm
540 Gaither Road Rockville, MD 20850