Complex antithrombotic therapy: determinants of patient preference and impact on medication adherence

Figures & data

Figure 1 Example of adaptive conjoint analysis trade-off question.

Note: “If these two treatment options were exactly the same except for the differences above, which would you prefer – the one on the LEFT, or the one on the RIGHT?”

Figure 2 Example of graphical representation of preferences for complex antithrombotic therapy (CAT) medication attributes.

Notes: “You have now finished all of the questions. The bars above show how important each of the seven medication characteristics are to you. The longer the bar is, the more important that characteristic was to you when you were answering the questions.”

Table 1 Patient characteristics (N=202)

Demographic characteristics
Average age (SD)	68.8 (7.0)
60–69 years	62.2%
70–79 years	28.9%
≥80 years	8.9%
Male	99.0%
White	84.1%
Black	10.9%
Other race	5.0%
Employed	14.9%
Annual household income >$40,000	31.8%
College graduate	17.9%
Excellent or very good health status	15.9%
Good health status	42.8%
Fair or poor health status	41.3%
Clinical characteristics
History of upper gastrointestinal event	6.5%
History of cerebrovascular accident	10.4%
History of myocardial infarction	24.9%
Transient ischemic attack	6.5%
Coronary artery disease	85.1%
PCI/CABG	40.3%
Medication characteristics
Current use of ACAP	0.5%
Current use of ASAC	33.8%
Current use of ASAP	57.2%
Current use of TRIP	8.5%
CAT duration <2 years	24.4%
CAT duration 3–5 years	29.3%
CAT duration >5 years	46.3%
NSAID use	9.5%
SSRI use	18.9%
PPI use	31.3%
H2-receptor blocker use	18.4%

Abbreviations: SD, standard deviation; PCI, percutaneous coronary intervention; CABG, coronary artery bypass graft; CAT, complex antithrombotic therapy; ACAP, combination therapy with anticoagulant and antiplatelet agent; ASAC, combination therapy with aspirin and anticoagulant; ASAP, combination therapy with aspirin and antiplatelet agent; TRIP, combination therapy with aspirin, antiplatelet agent and anticoagulant; NSAID, nonsteroidal anti-inflammatory drug; SSRI, selective serotonin reuptake inhibitor; PPI, proton pump inhibitor.

Figure 3 (A) Relative importance of CAT characteristics among patients age 60–69 years. (B) Relative importance of CAT characteristics among patients aged 70–79 years. (C) Relative importance of CAT characteristics among patients age >80 years.

Abbreviations: CAT, complex antithrombotic therapy; SD, standard deviation; MI, myocardial infarction; CVA, cerebrovascular accident; ICH, intracerebral hemorrhage; UGIE, upper gastrointestinal event.

Table 2 Patient utilities for CAT characteristics stratified by age cohort

Characteristic	Prevalence estimate	Utility,a mean (SD)
Age cohort: 60–69 years (n=123)
MI risk	9%	66.1 (11.0)
	10%	11.2 (6.9)
	13%	−77.3 (15.0)
CVA risk	7%	71.0 (8.3)
	13%	1.8 (5.3)
	19%	−72.8 (9.2)
ICH risk	3%	63.0 (12.8)
	11%	2.8 (5.2)
	24%	−65.9 (13.4)
UGIE risk	2%	40.2 (6.4)
	4%	2.6 (4.0)
	9%	−42.9 (8.6)
Stomach discomfort	11%	33.2 (7.0)
	20%	−1.6 (2.3)
	22%	−31.6 (7.4)
Number of medications	2 per day	29.4 (10.4)
	3 per day	0.9 (2.1)
Physical activity	No restrictions in activity	38.2 (13.2)
	Need to restrict activities	−38.2 (13.2)
Age cohort: 70–79 years (n=60)
MI risk	10%	62.1 (9.8)
	11%	7.5 (6.7)
	13%	−69.6 (14.3)
CVA risk	7%	79.7 (10.0)
	21%	−8.9 (4.9)
	25%	−70.7 (10.7)
ICH risk	3%	61.7 (11.9)
	11%	2.4 (5.9)
	24%	−64.1 (14.7)
UGIE risk	2%	42.3 (5.8)
	5%	1.8 (4.2)
	12%	−44.1 (7.4)
Stomach discomfort	11%	36.1 (9.2)
	20%	−1.8 (2.8)
	22%	−34.3 (9.0)
Number of medications	2 per day	27.3 (8.8)
	3 per day	0.9 (2.2)
Physical activity	No restrictions in activity	39.9 (13.2)
	Need to restrict activities	−39.9 (13.2)
Age cohort: ≥80 years (n=18)
MI risk	10%	55.1 (8.2)
	11%	6.9 (6.1)
	13%	−62.0 (10.7)
CVA risk	7%	81.9 (14.2)
	21%	−13.2 (6.9)
	25%	−68.7 (12.4)
ICH risk	3%	66.9 (12.0)
	11%	7.0 (5.11)
	24%	−74.0 (14.0)
UGIE risk	2%	43.2 (6.7)
	7%	1.5 (5.0)
	18%	−44.8 (7.1)
Stomach discomfort risk	11%	37.3 (14.1)
	20%	−2.8 (3.8)
	22%	−34.5 (12.5)
Number of medications	2 per day	25.6 (9.5)
	3 per day	−0.03 (1.6)
Physical activity	No restrictions in activity	40.2 (13.9)
	Need to restrict activities	−40.2 (13.9)

Note:

a In this context, “utility” is a number that represents the value a respondent associates with specific CAT regimen characteristics. A higher absolute value for utility indicates a greater rating of importance for the specific characteristics.

Abbreviations: CAT, complex antithrombotic therapy; MI, myocardial infarction; CVA, cerebrovascular accident; ICH, intracerebral hemorrhage; UGIE, upper gastrointestinal event.

Table 3 Treatment preferences for CAT strategies (N=201) stratified by age cohort

Scenario	Patients preferring each treatment option (%)
	ACAP	ASAP	ASAC	TRIP
Age cohort: 60–69 years (n=123)
Base case	72.2	4.3	23.5	0
Most convenient regimena	73.4	0.1	26.5	0.01
Most CV benefitb	39.1	46.2	14.8	0
Risk of UGIE decreasedc	1.3	3.8	95.0	0
Most CV benefit, least bleeding riskd	0.5	98.8	0.5	0.2
Age cohort: 70–79 years (n=60)
Base case	0.06	15.7	84.3	0
Most convenient regimena	0.5	0.8	98.7	0.01
Most CV benefite	16.8	35.7	47.5	0
Risk of UGIE decreasedc	0	16.1	83.9	0
Most CV benefit, least bleeding riskf	0.3	99.4	0.3	0.07
Age cohort: ≥80 years (n=18)
Base case	0.02	26.2	73.8	0
Most convenient regimena	0.4	4.8	94.8	0.01
Most CV benefite	6.8	56.2	37.0	0
Risk of UGIE decreasedc	0	11.9	88.1	0
Most CV benefit, least bleeding riskf	0.2	99.6	0.2	0.05

Notes:

a Most convenient dosing schedule = two medications per day; no restrictions in activity.

b MI risk decreased to 9% and CVA risk decreased to 7%.

c UGIE risk decreased to 3%.

d Most CV benefit = MI risk decreased to 9% and CVA risk decreased to 7%; least bleeding risks = ICH risk decreased to 3% and UGIE risk decreased 3%.

e MI risk decreased to 10% and CVA risk decreased to 7%.

f Most CV benefit = MI risk decreased to 10% and CVA risk decreased to 7%; least bleeding risks = ICH risk decreased to 3% and UGIE risk decreased 3%.

Abbreviations: CAT, complex antithrombotic therapy; ACAP, combination therapy with anticoagulant and antiplatelet agent; ASAC, combination therapy with aspirin and anticoagulant; ASAP, combination therapy with aspirin and antiplatelet agent; TRIP, combination therapy with aspirin, antiplatelet agent and anticoagulant; CV, cardiovascular; ICH, intracerebral hemorrhage; MI, myocardial infarction; CVA, cerebrovascular accident; UGIE, upper gastrointestinal event.

Figure 4 Change in medication adherence from baseline to 1-year after completing the preference-elicitation survey, stratified by whether participants were receiving their preferred CAT therapy (N=190).

Abbreviation: CAT, complex antithrombotic therapy.

Table S1 Patient perception of preference-elicitation exercise (N=56)

Domain: increased patient engagement with clinicians

“[The patient elicitation exercise] got me thinking about stuff that I never thought about before. Maybe I’ll start reading what I’m taking instead of depending on the doctor to tell me so and so […] cuz I have stopped taking some stuff that had given me like flu symptoms”. [pt 33]

“I believe [the exercise] is interesting number one. It’s informative. I never thought about all of this at one time. In other words, one of two things crossed my mind but never all of them. Based actually on the same thing, just a different way of putting each thing … Makes you think”. [pt 17]

“[…] the most difficult part of [the exercise] was the choice of one bad thing increasing with a decrease in a good thing happening. You know, not agood thing, but a different bad thing. Yeah, that [the trade-off] was a little difficult”. [pt 47]

“I think it’s good that you make me address these things … I think there’s a lot more that we need to start paying attention to”. [pt 24]

Domain: increased patient awareness of treatment preferences

“[The preference elicitation exercise] gave me more insight into what I am feeling about the medications that I’m taking, and how I’m feeling about the differences between the strokes, the heart attacks, the bleeds, and things like that. To be honest about it, I hadn’t really ever thought about it that much. So, this has gave me some kind of insight”. [pt 25]

“I can see where the benefit of knowing these things is better than the risk of not knowing about these health conditions, because I have them andI need to be more conscious about doing the things that I need to do and that I will be on these medicines for the rest of my life …”. [pt 4]

“[The preference elicitation exercise] shows what is more important to me … As far as my activities and the results that can happen … it shows that someone’s trying to see what the patient’s main concerns are”. [pt 9]

“I think [the preference elicitation exercise] is something that is beneficial. It really determines how you feel about your condition and the medications you take”. [pt 45]

“I just don’t want to have a heart attack and I don’t want to have a stroke, and they’re both up there (on graphical representation of preferences).

I don’t know that much about bleeding in the brain but it just didn’t sound good to me at all. I think knowing that the medicine I’m taking is going tokeep me from having either a stroke or heart attack, and so I’m going to keep taking [it]”. [pt 33]

Domain: increased activation

“My biggest concern is bleeding into the brain … and second up is the stroke and the heart attack … Yeah, [I] definitely think [the preference elicitation exercise] is worthwhile – to be given this information and be able to use it in my decision”. [pt 36]

“I would definitely have to ask [the physician] to monitor the ones I deem necessary in [the preference elicitation exercise] … I would question him about it and make sure he monitors it”. [pt 23]

“I am telling [the physician] my concerns when I have a checkup as far as the medications that I take”. [pt 9]

“If these percentages (on graphical representation of preferences) are anywhere near right, I’m gonna be talking to my doctor a little bit better”. [pt 17]

“I have never questioned a doctor and their medications … But I’ve, I think I’ve gotten to a point maybe I need to from now on”. [pt 24]

“Well, if there’s a decision to be made about what to do about my particular condition, this information and the way I feel on the survey would come into bearing on [the] decision that I would make with my physicians”. [pt 47]

Abbreviation: pt, patient.