Understanding and Discouraging Overuse of Potentially Harmful Screening Tests

Following the example of others, we will measure intent to accept screening services with possible or clear net harm with a single item "I plan to get screened for (name of screening test) in the next year." Because the recommended screening intervals for services under study are variable and not all participants will be due for screening in the next year, we will additionally query participants about plans for screening within the recommended screening interval (e.g. osteoporosis screening--5 years; CRC--10 years). Responses will range from "strongly disagree" to strongly agree". All outcomes will be measured before and after participants receive the information sheet. All data will be collected at the one study visit.

Perceived risk or susceptibility of disease will be measured for each disease state under study using one item that reads, "How likely is that you will get (insert prostate cancer, osteoporosis, or colon cancer) in the next 10 years?" Answers will be on a likert scale from "not at all likely" to "very likely."

Perceived Disease Severity will be measured for each disease state under study using the Revised Illness Perceptions Questionnaire for Healthy People. It includes the following four questions: 1) x (insert prostate cancer, osteoporosis, or colon cancer) has serious financial consequences; 2) x strongly affects the way the patient sees himself as a person; 3) x causes difficulties to those close to the patient; 4) x is very serious. Answers will be on a 5-point scale from "strongly disagree" to "strongly agree."

Two questions central to understanding each exemplar service (i.e. prostate cancer screening, osteoporosis screening, colon cancer screening) were selected to assess specific knowledge. Response options include true, false, or don't know.

Questions for prostate cancer screening are:

• Some men can live long, normal lives with untreated prostate cancer.
• Problems with sexual function and urination are common side effects of prostate cancer treatments.

Questions for colon cancer screening are:

• Most polyps in the bowel never become cancer.
• Bleeding and perforations are complications of a colonoscopy.

Questions for Osteoporosis screening are:

• Broken hip bones are uncommon before age 65.
• Treatments for osteoporosis can sometimes result in bone damage.

Six questions will assess participants' attitudes about each screening service under study.

Questions include:

• Screening for x(insert prostate cancer, colon cancer, osteoporosis) in healthy persons my age is a good idea.
• There is little harm to screening for x.
• I owe it to people close to me to get screened for x.
• I owe it to my doctor to get screened for x.
• I would regret not being screened for x.
• I do not feel any special responsibility to get screened for x.

Response options range from "strongly disagree" to "strongly agree".

Decisional balance will be measured by a single item for each screening service under study. Participants will be asked, "Which best describes how you feel right now?" Participants will select one of the following answers: 1) The benefits of X (insert prostate cancer, colon cancer, osteoporosis) screening greatly outweigh the harms; 2) The benefits of X screening somewhat outweigh the harms; 3) The benefits and harms of X screening are about the same; 4) The harms of X screening somewhat outweigh the benefits; and 5) The harms of X screening greatly outweigh the benefits.

Values Clarity will be measured with three items for the values subscale of the decisional conflict scale.

Items include:

• I am clear about which benefits matter most to me;
• I am clear about which harms and side effects matter most to me;
• I am clear about which is more important to me (the benefits or the harms);

Response options range from strongly disagree to strongly agree.

General screening knowledge will be assessed using 8 items developed by investigators.

Questions include:

• Screening means detecting disease before someone can see or feel any problem.
• Some diseases detected by screening won't cause any problems in a person's lifetime.
• In some cases, screening can lead to treatment that is not necessary.
• Screening never harms anyone.
• An abnormal screening test means I have the health condition for sure.
• A normal screening test means that I have am free of the health condition for sure.
• Screening can only decrease your chances of getting sick or dying if effective treatments are available.
• Screening can only decrease your chances of getting sick or dying if you live long enough for treatments to work.

Response options are true, false, or don't know.

General Screening Attitudes will be assessed at baseline by 38 questions that were developed by investigators and assessed for content validity by panel of experts. Questions assess the following sub-constructs:

General approach to screening, Value of Screening, Need to Know about Disease, Early Detection/Treatment, Benefits, Harms, Anticipated Regret in Choosing for/against screening, Duty/Responsibility to be screened, Effect on screening on MD/patient relationship.

Response options range from "strongly disagree" to "strongly agree" on a 5-point scale.

At post intervention, a subset of 12 of the 38 questions (1-2 from each subconstruct) will be used to assess changes in general screening attitudes.

Multiple variables will be measured to examine whether they moderate the effect of the intervention on the primary outcome intent for screening.

These variables include:

• self-efficacy for screening (1 question)
• cues to action (6-questions on sources of health information)
• perceived ambiguity of recommendations for screening (1 question)
• personality traits (10-item personality index)
• optimism (3 question subscale of life orientation test)
• need for cognition (3 items from need for cognition scale)
• health numeracy (3 items from Schwarz and Woloshin numeracy score)
• prior screening status (1 item per service)
• study site
• health insurance status