Information With or Without Numbers For Optimizing Reasoning About Medical Decisions (INFORM)

Describing the Comparative Effectiveness of Colorectal Cancer Screening Tests: The Impact of Quantitative Information

Experts believe that increasing the low uptake of screening for colorectal cancer (CRC) requires educating patients about all approved tests and helping them choose one that fits their preferences. As one motto puts it: "The best test is the one that gets done." Screening tests range from more invasive and very sensitive for polyps and cancer (colonoscopy) to less invasive and less sensitive (e.g., fecal immunochemical testing (FIT)). But it is unclear how best to educate patients about the options and the tradeoffs involved. Some guidelines recommend that decision aids, a promising tool in this area, provide patients with detailed quantitative information, including baseline risk, risk reduction, and chance of negative outcomes. But this sort of "comparative effectiveness" data can confuse patients, especially those with limited mathematical ability. Previous studies have not measured the effect of providing quantitative information to patients with varying levels of ability or interest or asked them whether such data is essential for their decision-making. The investigators will conduct a clinical trial to determine the impact on patients who view a decision aid (DA) that includes quantitative information versus a DA without such data. The investigators will also seek to determine whether numeracy moderates the effect of quantitative information.

decision aid, cancer screening, colorectal neoplasm, decision making, risk communication, numeracy, health literacy

Subjects view: A computer-based presentation regarding colorectal cancer (CRC) and screening for CRC with colonoscopy and stool testing. Includes excerpts from a video from the American Cancer Society. Computer-based presentation providing quantitative information regarding (a) the lifetime average probability of getting and dying from CRC, (b) the reduction in morbidity and mortality provided by colonoscopy and stool tests, (c) the sensitivity of colonoscopy and stool tests for finding cancer, (d) the false negative values of colonoscopy and stool tests for finding cancer, (e) the risk of heavy bleeding or colon injury from colonoscopy, and (f) the chance of having a positive stool test.

Subjects view: A computer-based presentation regarding colorectal cancer (CRC) and screening for CRC with colonoscopy and stool testing. Includes excerpts from a video from the American Cancer Society. Computer-based presentation providing verbal information regarding (a) the lifetime average probability of getting and dying from CRC, (b) the reduction in morbidity and mortality provided by colonoscopy and stool tests, (c) the sensitivity of colonoscopy and stool tests for finding cancer, (d) the false negative values of colonoscopy and stool tests for finding cancer, (e) the risk of heavy bleeding or colon injury from colonoscopy, and (f) the chance of having a positive stool test.

Completion of colonoscopy, fecal immunochemical testing (FIT), or other CRC screening test within 6 months of enrollment, based on documentation in the participants' electronic health record. If a patient completed both screening tests and the colonoscopy was a follow-up to a positive FIT, they were considered having completed a FIT only. If the FIT was negative and the patient still had a colonoscopy, they were considered to have completed both tests.

Multiple choice question assessing subject's intention in getting a CRC screening test in the next 6 months. The response options were: 5=Definitely, 4=Probably, 3=May or may not, 2=Probably not, and 1=Definitely not. Higher positive change means CRC screening intention increased. Increased intention to be screened is a better outcome.

1 day (baseline [before viewing decision aid] and post-intervention [immediately after viewing decision aid])

Multiple choice questions assessing subject's perception of how likely they are to get colon cancer in the next 5 years, in the next 10 years, and sometime during their lifetime. Each had response options: 4=very likely, 3=somewhat likely, 2=somewhat unlikely, and 1=very unlikely. The mean of the 3 questions was calculated (each combined score has a range of 1 to 4) at baseline and post-intervention and then change from baseline was calculated using the mean at post-intervention minus the mean at baseline. The range for change could be from -3 to 3 with higher values meaning an increase in perceived risk which is a better outcome.

1 day (baseline [before viewing decision aid] and post-intervention [immediately after viewing decision aid])

Perceived Benefits of Colorectal Cancer Screening With Fecal Immunochemical Test (FIT) and Colonoscopy: Change From Baseline to Post-intervention

Assessed separately for colonoscopy (4 questions) and FIT (4 questions), using items drawn from validated scales for measuring benefits and self-efficacy of colonoscopy and FIT. All items had Likert-type response options where 5=strongly agree to 1=strongly disagree. Mean values were calculated within each set of questions (each combined score has a range of 1 to 5) at baseline and post-intervention and then change from baseline was calculated using the mean at post-intervention minus the mean at baseline. The range for change could be -4 to 4 with higher values meaning perceived benefits increased which is a better outcome.

1 day (baseline [before viewing decision aid] and post-intervention [immediately after viewing decision aid])

Perceived Barriers to Colorectal Cancer Screening With Fecal Immunochemical Test (FIT) or Colonoscopy: Change From Baseline to Post-intervention

Assessed separately for colonoscopy (11 questions) and FIT (9 questions), using items drawn from validated scales for measuring barriers and self-efficacy of colonoscopy and FIT. All items had Likert-type response options where 5=strongly agree to 1=strongly disagree. Mean values were calculated within each set of questions (each combined score has a range of 1 to 5) at baseline and post-intervention and then change from baseline was calculated using the mean at post-intervention minus the mean at baseline. The range for change could be -4 to 4 with lower values meaning perceived barriers decreased which is a better outcome.

1 day (baseline [before viewing decision aid] and post-intervention [immediately after viewing decision aid])

Knowledge of Colorectal Cancer (CRC) and Colorectal Cancer Screening: Change in Number of Correct Answers From Baseline to Post-intervention

Qualitative knowledge is assessed with five multiple choice and five true/false questions regarding general information (including risk factors, screening test options, and test frequency) of CRC and CRC screening. Knowledge scores were derived by summing correct responses to the 10 individual knowledge questions (range, 0-10), and change from baseline was calculated using the knowledge score at post-intervention minus the knowledge score at baseline. The range for change could be 0 to 10 with higher values meaning an increase in knowledge which is a better outcome.

1 day (baseline [before viewing decision aid] and post-intervention [immediately after viewing decision aid])

Decision conflict is assessed using the16-item Decision Conflict Scale. Scores will range from 0 (low decision conflict) to 100 (high decision conflict). Negative change means decision conflict decreased. A decrease in decision conflict is a better outcome.

1 day (baseline [before viewing decision aid] and post-intervention [immediately after viewing decision aid])

Subjective numeracy was determined using the Subjective Numeracy Scale (SNS), a validated instrument that involves 8 Likert-type questions regarding the participant's preference for or dislike of numeric information and their perception of their ability to understand it. Each item has a six-point response option from 1-6. The higher the number, the higher the subjective numeracy. All participants were divided into two groups: above (high numeracy) and below (low numeracy) the median for their total subjective numeracy score.

Inclusion Criteria: Have not had colonoscopy performed in last 10 years, sigmoidoscopy in last 5 years, or fecal occult blood testing (including FIT) in last 1 year and have a scheduled appointment or due to schedule an appointment with a healthcare practitioner at our performance sites. Exclusion Criteria: undergoing workup for symptoms consistent with colon cancer, such as weight loss or rectal bleeding have a diagnosis or medical history conferring elevated risk for CRC including polypectomy or colon cancer, inflammatory bowel disease, certain inherited syndromes, or a significant family history of CRC are unable to speak and read English.