Table 5.
—[Section 6.0] Stroke and MI Prophylaxis Studies
| Study/Year | Patient Population | Study Design | Method of Preference Elicitation | Therapy | Outcomes Considered | Summary of Results |
| Bergus et al24/2002 |
217 patients sampled from a GP office |
RCT comparing order of risk information on treatment decision |
Hypothetical scenario of a 40% carotid arterial stenosis |
A |
Stroke | Participants were randomized to receive either (1) benefits of therapy and then risks or (2) risks of therapy and them benefits. Approximately 77% of participants would accept aspirin with 1% stroke risk reduction, 40% rate of GI side effects, and 33% chance of bleeds (of which most would be minor bleeds). After reading identical introductory information about the use of aspirin, favorability ratings were similar between two groups. After being given more-detailed information (eg, risks, benefits), the study arm that received benefits before risks had significantly reduced favorability ratings than those who received information in the opposite order (reduction of 10.9/100 vs a reduction of 5.2/100). |
| GI side effects (bleeding, ulcers) |
Participants became less favorable to the intervention as they learned more about the risks (as rated on a scale of 0-100, where 100 is most favorable). Health risks associated with stroke were rated 78/100 in terms of the importance that this information plays on decision-making. Health risks associated with the intervention was rated 55/100, and health benefits associated with the intervention was rated 76.5/100. |
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| Man-Son-Hing et al25/2000 |
42 patients previously prescribed aspirin as part of an RCT |
Cross-sectional interviews (three scenarios with varying risks) |
PTOT VAS (HSU)/decision analysis |
A/NT |
Minor stroke | Given an increase in serious GI bleeds with aspirin of 2% over 5 y, the mean threshold risk reduction in MI required for patients to take aspirin using PTOT was 0.45% (0.31) and for stroke, 0.32% (0.28). Thus, the disutility patients placed on MI was on average more than four times that of bleeding, and for stroke, it was more than six times that of bleeding. Participant treatment thresholds elicited by the PTOT were consistently lower than using the decision analysis model. See Table 1 for additional HSUs. |
| Major stroke | ||||||
| Major GI bleed | ||||||
| MI | ||||||
| Daily pill | ||||||
| Man-Son-Hing et al26/2001 |
54 participants, 42 of whom had enrolled in an RCT to examine the efficacy of aspirin to prevent cardiovascular events and 12 who had not |
Cross-sectional interviews (three scenarios with varying risks) |
PTOT |
A/NT |
Minor stroke | There are significant differences in treatment thresholds for those enrolled in the APPLE (Aspirin for Primary Prevention in the Low-risk Elderly) pilot study (n = 42) vs those who were not (n = 12). |
| Major stroke | ||||||
| Major GI bleed | ||||||
| MI | ||||||
| Daily pill | ||||||
| Montori et al27/2003 | 206 patients with diabetes | Cross-sectional survey | Survey that included a 5-point Likert scale | A | GI bleed | Patients taking aspirin placed a statistically significantly higher value on avoiding cardiovascular events than treatment-associated side effects, whereas patients not taking aspirin placed an equal value on the two. On a 5-point Likert scale, participants not taking aspirin vs those taking aspirin rated the importance of avoiding heart attack with a score of 4.3 (IQR, 3.7-5) and 5 (IQR, 4.3-5; P<.001) and stroke with a score of 4.3 (IQR, 3.7-5) and 5 (IQR, 4.3-5; P<.0001). |
| Side effects | ||||||
| Stroke | ||||||
| MI |