Fisher, Deborah A.

AbstractBackgroundGuidelines include several options for average‐risk colorectal cancer (CRC) screening that vary in aspects such as invasiveness, recommended frequency, and precision. Thus, patient and provider preferences can help identify an appropriate screening strategy. This study elicited CRC screening preferences of physicians and individuals at average risk for CRC (IAR).MethodsIAR aged 45–75 years and licensed physicians (primary care or gastroenterology) completed an online discrete choice experiment (DCE). Participants were recruited from representative access panels in the US. Within the DCE, participants traded off preferences between screening type, screening frequency, true‐positive, true‐negative, and adenoma true positive (physicians only). A mixed logit model was used to obtain predicted choice probabilities for colonoscopy, multi‐target stool DNA (mt‐sDNA), fecal immunochemical test (FIT), and methylated septin 9 (mSEPT9) blood test.ResultsPreferences of IAR and physicians were affected by screening precision and screening type. IAR also valued more regular screening. Physicians preferred colonoscopy (96.8%) over mt‐sDNA (2.8%; p < 0.001), FIT (0.3%; p < 0.001) and mSEPT9 blood test (0.1%; p < 0.01). IAR preferred mt‐sDNA (38.8%) over colonoscopy (32.5%; p < 0.001), FIT (19.2%; p < 0.001), and mSEPT9 blood test (9.4%; p < 0.001). IAR naïve to screening preferred non‐invasive screening (p < 0.001), while the opposite was found for those who previously underwent colonoscopy or sigmoidoscopy.ConclusionsWhile physicians overwhelmingly preferred colonoscopy, preferences of IAR were heterogenous, with mt‐sDNA being most frequently preferred on average. Offering choices in addition to colonoscopy could improve CRC screening uptake among IAR.This study used a discrete choice experiment in the US to elicit preferences of physicians and individuals at average risk for colorectal cancer screening modalities and their characteristics.

65 Background: There is consensus that the proportion of the average-risk US population up-to-date with CRC screening (58-65%) is insufficient. However, estimates of average risk CRC screening rates are inconsistent and impacted by inclusion of higher-risk individuals, and differing study designs. Accurate measurement of population screening rates is key to addressing gaps in care and assessing the impact of newer CRC screening tests. Methods: The study included individuals aged 50-75 years in a large de-identified claims database, with continuous enrollment during year of analysis, and a variable length baseline enrollment of 1-10 years. Average-risk designation excluded higher risk diagnoses (CRC familial syndromes, colorectal polyp or history of colorectal polyp, history of/current CRC, family history of gastrointestinal cancer, and inflammatory bowel disease). Up-to-date status was assessed within guideline-based time periods: colonoscopy (10 years); FIT or FOBT (annually); mt-sDNA (3 years); flexible sigmoidoscopy/CT colonography (5 years). Analyses assessed the proportion estimated as up-to-date and examined the sensitivity to: a) patient population (average-risk only vs. including higher-risk); b) study design (yearly cross-sectional vs. cohort of 50-year-old patients; c) methods (percent in patients with 10 years of enrollment vs. Kaplan Meier (KM) of censored variable pre-screening period). Results: The cross-sectional analysis average-risk population included 5.3 million individuals. Estimates of the proportion of those up-to-date with screening guidelines for average-risk patients varied by study design, population, and estimation method. KM estimates among the average-risk population (50-75) showed 49-50% were up-to-date in each calendar year. Including higher-risk patients in the KM analysis resulted in 70% up-to-date among the mixed average+higher-risk population. Using a cohort study design (average-risk patients aged 60 with 10 years of baseline data), 65% were up-to-date by age 60. Conclusions: In the base case analysis only half of average risk individuals were up-to-date with CRC screening, a rate lower than typically cited. Sensitivity analyses resulted in substantially different estimates and demonstrate the importance of clearly communicating the methodology used to define the study population. Higher rates quoted in the lay press and medical publications may be based on mixed populations of average+higher-risk individuals or on study designs that do not represent the full population at risk.

60 Background: Several colorectal cancer (CRC) screening options are considered in guidelines for individuals at average-risk (IAR). These options differ in aspects such as invasiveness, recommended frequency, and precision that need to be compared and weighed. This study elicited and compared the relative importance that physicians and IAR place on these screening aspects. Methods: Primary care physicians [PCPs] and gastroenterologists [GIs] who recommended/performed ≥1 screening one month prior to study and adult IAR completed a discrete choice experiment (DCE). Participants repeatedly chose between screening tests described by type of test, frequency, true-positive (TP), true-negative (TN), and adenoma TP (physicians only). The instrument was tested in qualitative (physicians: n=6; IAR: n=6) and quantitative pilots (physicians: n=100; IAR: n=202). A mixed logit model was used to estimate relative attribute importance (RAI) and predicted choice probabilities for colonoscopy, multi-target stool DNA (mt-sDNA), fecal immunochemical test (FIT), and methylated septin 9 (mSEPT9) blood test. Generalizability to the population was confirmed. Results: 1,249 IAR and 400 physicians participated. IAR were 46% male and the mean age was 58.9. Physicians were 79% male and their mean age was 53.4. Preferences were most affected by TP rates (IAR RAI=58%; physicians RAI=42%). Physicians also placed high importance (RAI=41%) on adenoma TP rates. TN rates (IAR RAI=33%; physician RAI=9%), frequency (IAR RAI=6%; physician RAI=2%) and type (IAR RAI=4%; physician RAI=6%) were less important. Despite both IAR and physicians placing most importance on precision, preferences for screening modalities differed. On average, physicians preferred colonoscopy, while IAR preferred mt-sDNA over colonoscopy (p<0.001). Both preferred mt-sDNA and colonoscopy over FIT (p<0.001), with a mSEPT9 blood test being least preferred (p<0.001). Preferences of IAR were heterogeneous with individuals who underwent colonoscopy or sigmoidoscopy screening preferring colonoscopy and the rest preferring mt-sDNA (p<0.001). Conclusions: While both GI and PCPs overwhelmingly preferred colonoscopy, preferences of IAR were heterogenous, with mt-sDNA being preferred on average other modalities. Offering choices in addition to colonoscopy could improve screening uptake. [Table: see text]

Abstract Colorectal cancer–screening models commonly assume 100% adherence, which is inconsistent with real-world experience. The influence of adherence to initial stool-based screening [fecal immunochemical test (FIT), multitarget stool DNA (mt-sDNA)] and follow-up colonoscopy (after a positive stool test) on colorectal cancer outcomes was modeled using the Colorectal Cancer and Adenoma Incidence and Mortality Microsimulation Model. Average-risk individuals without diagnosed colorectal cancer at age 40 undergoing annual FIT or triennial mt-sDNA screening from ages 50 to 75 were simulated. Primary analyses incorporated published mt-sDNA (71%) or FIT (43%) screening adherence, with follow-up colonoscopy adherence ranging from 40% to 100%. Secondary analyses simulated 100% adherence for stool-based screening and colonoscopy follow-up (S1), published adherence for stool-based screening with 100% adherence to colonoscopy follow-up (S2), and published adherence for both stool-based screening and colonoscopy follow-up after positive mt-sDNA (73%) or FIT (47%; S3). Outcomes were life-years gained (LYG) and colorectal cancer incidence and mortality reductions (per 1,000 individuals) versus no screening. Adherence to colonoscopy follow-up after FIT had to be 4%–13% higher than mt-sDNA to reach equivalent LYG. The theoretical S1 favored FIT versus mt-sDNA (LYG 316 vs. 297; colorectal cancer incidence reduction 68% vs. 64%; colorectal cancer mortality reduction 76% vs. 72%). The more realistic S2 and S3 favored mt-sDNA versus FIT (S2: LYG 284 vs. 245, colorectal cancer incidence reduction 61% vs. 50%, colorectal cancer mortality reduction 69% vs. 59%; S3: LYG 203 vs. 113, colorectal cancer incidence reduction 43% vs. 23%, colorectal cancer mortality reduction 49% vs. 27%, respectively). Incorporating realistic adherence rates for colorectal cancer screening influences modeled outcomes and should be considered when assessing comparative effectiveness. Prevention Relevance: Adherence rates for initial colorectal cancer screening by FIT or mt-sDNA and for colonoscopy follow-up of a positive initial test influence the comparative effectiveness of these screening strategies. Using adherence rates based on published data for stool-based testing and colonoscopy follow-up yielded superior outcomes with an mt-sDNA versus FIT-screening strategy.