Change to FIT Increased CRC Screening Rates: Evaluation of a US Screening Outreach Program
Published Online: October 24, 2012
Elizabeth G. Liles, MD, MSCR; Nancy Perrin, PhD; Ana Gabriela Rosales, MS; Adrianne C. Feldstein, MD, MS; David H. Smith, RPh, MHA, PhD; David M. Mosen, PhD, MPH; and Jennifer L. Schneider, MPH
Colorectal cancer (CRC) is the second-leading cause of cancer death in the United States, and affects men and women almost equally.1-3 The US Preventive Services Task Force (USPSTF) recommends screening with any of 3 options, including fecal testing, flexible sigmoidoscopy, or colonoscopy. Screening for CRC with fecal occult blood testing done annually or biennially has been shown to decrease mortality from colorectal cancer by 15% to 33%, primarily through detection of early-stage cancers.4-9 The guaiac fecal occult blood test (gFOBT) has a known positive balance of benefit and risk in screening populations, is the least expensive screening method, and is preferred over endoscopy in 30% to 55% of patients.10-12 However, gFOBT has limitations in the areas of test adherence and test performance because testing requires dietary and medication restrictions during the 3 days that 3 separate stool samples are collected—a cumbersome protocol that can interfere with test completion.13
While adherence to test completion in the initial round of screening with gFOBT in 3 large randomized trials was 59% to 67%,5-7 smallerscale studies have demonstrated lower 1-time screening completion rates using gFOBT by 25% to 30%.14,15 Retaining patients in annual or biennial gFOBT screening programs has proved challenging, with observed rescreen rates of approximately 50% on a second round.9,16 The fecal immunochemical test (FIT) may improve upon these rates. Previous randomized studies have shown that adherence to 1-time completion of a 1-sample or 2-sample FIT is 10% to 12% greater than adherence to gFOBT, and that the sensitivity of FIT is equal to or greater than FOBT.14,15,17-19 A single (3-sample) gFOBT detects about 12% to 38% of cancers,20-22 whereas a 1-sample FIT detects 25% to 69% of cancers,22-24 and a 3-sample FIT detects 66% to 92% of cancers.22,24-27 As a result, in 2008, multiple professional societies endorsed the use of 4 types of FITs for colorectal cancer screening as a replacement for gFOBT in the United States.1,28 However, it remains unclear to what extent a transition from gFOBT to FIT will improve screening test completion in large community-based populations and which specific populations may benefit the most. We capitalized on a natural experiment by analyzing completion rates before and after the change from gFOBT to FIT.
The protocol for this study was approved by the institutional review board within the study health maintenance organization (HMO).
Study Site and Data Sources
The study was conducted at Kaiser Permanente Northwest (KPNW), a not-for-profit HMO in the Pacific Northwest with about 485,000 members. The membership of KPNW is similar to the local insured community.29 Electronic records and a patient survey described below provided clinician and patient data.
KPNW maintains a CRC screening clinical practice guideline based upon the recommendations of the USPSTF. Each of the USPSTF-recommended CRC screening modalities (ie, fecal testing, flexible sigmoidoscopy, or colonoscopy) is a covered benefit and available to patients, although fecal testing is encouraged through systemwide outreach efforts in lower-risk individuals. The study site has had an automated call CRC reminder program in place since January 2008; details of the patient selection process for outreach and of the automated call system have been published. The system targets averagerisk individuals who are not being actively treated for major diseases (eg, cancer), or receiving nursing home or hospice care.30 Each month, approximately 5000 eligible HMO members receive a telephone call with an offer for a fecal test to be sent to their home. Included in the mailed packets are the test, instructions, and a card stock envelope addressed to the KPNW laboratory for return. Those who request the test but do not complete it within 6 weeks receive up to 2 reminder phone calls, 6 weeks apart.
In April 2009, KPNW switched from sending the 3-sample gFOBT to sending a single-sample FIT that required no dietary or medication restrictions—the OC -Micro FIT (Polymedco, Cortland Manor, New York).
Study Design Overview
The retrospective cohort study examined colorectal cancer screening test completion among those receiving an automated telephone call (ATC) during 2 successive time periods: 1) The “gFOBT era,” a 15-month period during which the gFOBT was routinely offered through ATC outreach, and 2) a 9-month “FIT era.” We also analyzed the impact of practicelevel variables (eg, primary care provider [PCP] assignment, primary care utilization, and specialty care utilization) and patient-level variables (eg, age, gender, number of medications, body mass index [BMI], and length of HMO membership) on overall screening completion during the 2 different observation periods.
Additionally, we mailed a survey to 2000 patients who received an ATC during 1 or both time periods. This survey was designed to understand the barriers and facilitators that patients encountered in their efforts to complete colorectal cancer screening. For the purposes of this analysis, we discuss the specific answers among only those respondents who answered questions about both tests, because they had had prior experience with each type of fecal test.
This retrospective cohort study was conducted in 2 phases. The Figure outlines the study population flow.
Cohort Population: The cohort consisted of HMO members aged 50 to 80 years who were overdue for CRC screening at the beginning of each month of an observation period, and who received an ATC from the CRC screening outreach program at KPNW.
We utilized 2 observation periods: 1) The “gFOBT era”—a 15-month period during which the gFOBT was routinely offered through ATC outreach from January 1, 2008, through March 31, 2009 (n = 59,876); and 2) a corresponding “FIT era” from April 1, 2009, through December 31, 2009 (n = 32,601), excluding a single month (September 2009) in which KPNW was piloting a different type of ATC vendor.
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