Table 1.
Attributes and levels used in stated-preference survey.
| Attribute, as presented to respondent (analysis short form) | Levels, as presented to respondent | Analysis short form of level name |
|---|---|---|
| A. How is it done? (process) | You place 2 stool samples on to special cards for 3 consecutive days and return them to your doctor for testing. | stool |
| A flexible tube is inserted into your rectum and through your colon. This is done at the hospital. | scope | |
| Air and a white liquid are injected into your colon through a tube inserted into your rectum. X-rays are taken as the liquid moves through your colon. This is done at the hospital. | barium enema | |
| You have a CT scan. This is done at the hospital. | CT | |
| B. Is there pain or discomfort? (pain) | You feel no pain or discomfort. | none |
| You may feel pain or discomfort like intense cramps. | mild | |
| You will be given a sedative so that you should only feel pressure or mild discomfort, but you will feel sleepy and need to relax for the rest of the day. | sedative | |
| C. How often will the screening test be done? (frequency) | You will have the screening test only once. | once |
| You will have the screening test every 10 years. | q 10y | |
| You will have the screening test every 5 years. | q 5y | |
| You will have the screening test every year. | annual | |
| D. What do I do to prepare? (preparation) | For 5 days you must avoid certain foods (such as red meat and some vegetables) and medications (such as aspirin and vitamin C). | diet |
| Before the test you must take a laxative to clean your colon. After the laxative, you can only have clear liquids until after your test. | laxative | |
| One hour prior to the test you must have an enema to empty the last part of your colon. | enema | |
| No preparation is required. | none | |
| E. If this screening test result is abnormal, will an additional test be needed to confirm whether you have cancer? (follow-up) | No. | none |
| Yes, you will undergo another test on a different day. | yes | |
| F. If 10 people without cancer get this screening test, how many of them will the test say do have cancer? (specificity) | The screening test will say that 5 out of 10 people without cancer do have cancer. | 50% |
| The screening test will say that 2 out of 10 people without cancer do have cancer. | 80% | |
| The screening test will say that 1 out of 10 people without cancer do have cancer. | 90% | |
| G. If 10 people with cancer get this screening test, how many of them will the test say do not have cancer? (sensitivity) | The screening test will say that 6 out of 10 people with cancer do not have cancer. | 40% |
| The screening test will say that 3 out of 10 people with cancer do not have cancer. | 70% | |
| The screening test will say that 1 out of 10 people with cancer do not have cancer. | 90% | |
| H. How many people who get this screening test have a complication? (complication risk) | No one who gets this screening test will have a complication. | none |
| 1 out of 100 people who get this screening test will have a complication. | 1/100 | |
| 1 out of 1,000 people who get this screening test will have a complication. | 1/1,000 to 1/10,000* | |
| 1 out of 10,000 people who get this screening test will have a complication. | ||
| I. What is the cost of the screening test to me? (cost) | $25 | $25 |
| $100 | $100 | |
| $500 | $500 | |
| $1000 | $1000 |
*
Respondents ranked 1/1,000 higher than 1/10,000, therefore we merged these two levels