Background
Methods
Description of the example study
Model description
The prevalence of atherosclerosis and the risk of stroke
Model assumptions
Cost-effectiveness analysis
Input parameter | Value* | Range$ | Distribution | Source |
---|---|---|---|---|
Probability of early death (within 30 days) | EuroSCORE risk equation | [37] | ||
Probability death is due to fatal stroke event | 13.2% | 7.5 – 20.2% | Beta(14,92) | [25] |
Probability that a stroke event is not fatal | 80.8% | 75.3 – 85.8% | Beta(173,41) | [38] |
Probability that stroke is caused by emboli | 71.0% | 63.3 – 77.8% | Beta(107,44) | [38] |
Manual palpation: sensitivity | 31% | 22 – 40% | Beta(33,73) | [31] |
Manual palpation: specificity | 98% | 96 – 100% | Beta(179,4) | [31] |
Modified TEE: sensitivity | 97% | 94 – 100% | Beta(124,4) | [39] |
Modified TEE: specificity | 80% | 74 – 85% | Beta(173,44) | [39] |
Risk reduction of post-operative stroke due to adaptations when applying the modified TEE | 0.46 | 0.196 – 0.910 | LogNormal (−0.864, 0.392) | [25]† |
Probability of a major adaptation of surgery given a patient with atherosclerosis | 2.7% | 2.3 – 3.1% | Beta(163,5888) | [40] |
Risk of death (year 1–2 post-surgery): age < 61 years | 1.18% | 0.82 – 1.42% | Uniform | [41] ‡ |
Risk of death (year 1–5 post-surgery): age 61–70 years | 2.33% | 1.95 – 2.71% | Uniform | [41] ‡ |
Risk of death (year 1–5 post-surgery): age > 70 years | 4.35% | 3.49 – 5.24% | Uniform | [41] ‡ |
Utility of the ‘Post Stroke’ health state | 0.439 | 0.186 – 0.653 | Triangular | [42]^ |
Utility of the ‘No complications’ health state | 1 | - | - | Default |
Cost of death (Euros) | 2,736 | 1,368 – 5,471 | Uniform | Expert opinion [43] |
Diagnostic cost of modified TEE tool (Euros) | 212 | 184 –243 | Gamma | Manufacturer |
Cost of fatal stroke event (Euros) | 2,736 | 1,368 – 5,471 | Uniform | # |
Discount rate for costs | 4.0% | - | - | Dutch guidelines |
Discount rate for effects | 1.5% | - | - | Dutch guidelines |
Results
Pre-existing evidence on the accuracy of the two diagnostic strategies
Expected early mortality in cardiac surgical patients
Impact of diagnostic tests on surgical management, costs, and the risk of embolic stroke
Cost-effectiveness outcomes
Subgroup
|
Manual palpation strategy
|
Modified TEE strategy
| ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Gender | Age | % atherosclerosis | EuroSCORE predictedmortality risk | Chance ofminor adaptation | Chance ofmajor adaptation | Risk of stroke | Life-years after surgery | Chance of minor adaptation | Chance of majoradaptation | Risk of stroke | Life-yearsafter surgery | |||
non-fatal | fatal | non-fatal | fatal | |||||||||||
1 | Men | 55 yr | 10% | 1.04% | 3.03% | 0.08% | 1.01% | 0.24% | 23.06 | 9.43% | 0.26% | 0.84% | 0.23% | `23.10 |
2 | Men | 55 yr | 15% | 1.08% | 4.54% | 0.13% | 1.04% | 0.24% | 23.05 | 14.14% | 0.39% | 0.86% | 0.23% | 23.10 |
3 | Women | 55 yr | 10% | 1.41% | 3.04% | 0.08% | 1.36% | 0.32% | 26.09 | 9.43% | 0.26% | 1.14% | 0.31% | 26.16 |
4 | Women | 55 yr | 15% | 1.46% | 4.54% | 0.13% | 1.40% | 0.33% | 26.08 | 14.14% | 0.39% | 1.16% | 0.31% | 26.15 |
5
|
Men
|
65 yr
|
20%
| 1.61% | 6.07% | 0.17% | 1.53% | 0.36% | 15.17 | 18.84% | 0.52% | 1.25% | 0.33% | 15.22 |
6 | Men | 65 yr | 30% | 1.71% | 9.10% | 0.25% | 1.61% | 0.38% | 15.15 | 28.29% | 0.78% | 1.29% | 0.33% | 15.20 |
7
|
Women
|
65 yr
|
20%
| 2.14% | 6.06% | 0.17% | 2.05% | 0.48% | 17.49 | 18.84% | 0.52% | 1.67% | 0.44% | 17.56 |
8 | Women | 65 yr | 30% | 2.28% | 9.10% | 0.25% | 2.15% | 0.50% | 17.44 | 28.27% | 0.78% | 1.71% | 0.44% | 17.53 |
9 | Men | 75 yr | 40% | 3.18% | 12.15% | 0.34% | 2.94% | 0.69% | 8.73 | 37.72% | 1.04% | 2.31% | 0.59% | 8.80 |
10 | Men | 75 yr | 50% | 3.36% | 15.13% | 0.42% | 3.10% | 0.72% | 8.70 | 47.13% | 1.31% | 2.39% | 0.60% | 8.77 |
11 | Women | 75 yr | 40% | 4.13% | 12.13% | 0.34% | 3.83% | 0.90% | 10.44 | 37.70% | 1.04% | 3.02% | 0.77% | 10.55 |
12 | Women | 75 yr | 50% | 4.34% | 15.21% | 0.42% | 4.02% | 0.94% | 10.40 | 47.11% | 1.31% | 3.09% | 0.78% | 10.53 |
Subgroup
|
Manual palpation strategy
|
Modified TEE strategy
| Modified TEE vs Manual palpation | |||||||
---|---|---|---|---|---|---|---|---|---|---|
Gender | Age | % atherosclerosis | Expectedcosts (€) | Expected effects(QALY) | Expectedcosts(€) | Expectedeffects(QALY) | Expectedincremental costs (€) | Expectedincrementaleffects (QALY) | ExpectedICER(€ / QALY) | |
1 | Men | 55 yr | 10% | 25,896 | 14.31 | 25,943 | 14.32 | 47 | 0.01 | 4,651 |
2 | Men | 55 yr | 15% | 25,936 | 14.31 | 25,970 | 14.32 | 34 | 0.01 | 3,376 |
3 | Women | 55 yr | 10% | 25,984 | 15.34 | 25,993 | 15.36 | 10 | 0.02 | 481 |
4 | Women | 55 yr | 15% | 26,012 | 15.33 | 26,009 | 15.36 | −3 | 0.03 | −103* |
5
|
Men
|
65 yr
|
20%
| 26,589 | 10.75 | 26,581 | 10.77 | −8 | 0.02 | −420* |
6 | Men | 65 yr | 30% | 26,671 | 10.74 | 26,639 | 10.76 | −32 | 0.02 | −1,603* |
7
|
Women
|
65 yr
|
20%
| 26,720 | 11.83 | 26,662 | 11.86 | −58 | 0.03 | −1,946* |
8 | Women | 65 yr | 30% | 26,815 | 11.80 | 26,722 | 11.84 | −93 | 0.04 | −2,318* |
9 | Men | 75 yr | 40% | 27,629 | 7.01 | 27,479 | 7.04 | −149 | 0.03 | −4,973* |
10 | Men | 75 yr | 50% | 27,733 | 6.99 | 27,547 | 7.03 | −186 | 0.04 | −4,648* |
11 | Women | 75 yr | 40% | 28,563 | 8.10 | 28,182 | 8.15 | −380 | 0.05 | −7,608* |
12 | Women | 75 yr | 50% | 28,719 | 8.08 | 28,264 | 8.14 | −455 | 0.06 | −7,579* |