Table 3.
Results of Decision Models Testing Performing Versus Not Performing Direct Drug Challengesa in Patients With a Penicillin Allergy Label
| Model Characteristics | Cost Associated With Performing Allergy Testsb,c | Cost Associated With Not Performing Allergy Testsb,c | Incremental Net Benefitb,d | Minimum % Delabeled So That Testing is Cost-savinge | Probabilistic Sensitivity Analysis Results | |||||
|---|---|---|---|---|---|---|---|---|---|---|
| Patient Type | Cases in Which a Direct DC Was Performed | Region | % of Simulations With Testing as Best Strategy | Average Incremental Net Benefit | Median Incremental Net Benefit (25th–75th Percentile) | % Delabeled So That Testing Is the Best Strategy in > 50% of Simulationsf | ||||
| Inpatients | NIR | All | $4888 | $5379 | $492 | 16.6% | 76.4% | $492 | $197 ($10–$472) | 33% |
| US | $13 657 | $15 449 | $1792 | 5.2% | 86.0% | $1764 | $418 ($134–$1063) | 19% | ||
| Europe | $5719 | $6314 | $595 | 14.0% | 81.3% | $582 | $183 ($39–$406) | 35% | ||
| Portugal | $4123 | $4536 | $414 | 19.9% | 82.2% | $410 | $192 ($44–$424) | 36% | ||
| All | All | $4851 | $5362 | $511 | 13.5% | 78.4% | $521 | $224 ($29–$501) | 26% | |
| US | $9291 | $10 634 | $1343 | 5.5% | 86.4% | $1339 | $412 ($150–$934) | 16% | ||
| Europe | $3495 | $3924 | $429 | 15.9% | 83.7% | $432 | $187 ($50–$388) | 31% | ||
| Portugal | $2870 | $3211 | $341 | 19.8% | 84.0% | $342 | $196 ($53–$394) | 30% | ||
| Outpatients | NIR | All | $3518 | $5887 | $2369 | 5.4% | 84.6% | $2368 | $1292 ($323–$3020) | 10% |
| US | $2952 | $3307 | $355 | 27.8% | 84.0% | $358 | $260 ($70–$537) | 35% | ||
| Europe | $3360 | $9538 | $6178 | 2.0% | 61.4% | $5809 | $552 (−$395 to 3867) | 20% | ||
| Portugal | $1542 | $40 367 | $2495 | 5.1% | 59.4% | $2670 | $246 (−$253 to $1842) | 40% | ||
| All | All | $3480 | $6124 | $2644 | 3.8% | 85.7% | $2665 | $1443 ($380–$3466) | 7% | |
| US | $2890 | $3307 | $417 | 18.8% | 88.1% | $410 | $309 ($115–$578) | 23% | ||
| Europe | $2793 | $9538 | $6745 | 1.5% | 62.8% | $6566 | $664 (−$393 to $4520) | 15% | ||
| Portugal | $1355 | $4037 | $2682 | 3.8% | 61.5% | $2767 | $291 (−$232 to $1948) | 28% |
In cases not reporting a nonimmediate reaction, skin tests were performed and, if negative, followed by a drug challenge.
Abbreviations: $, United States dollars; NIR, nonimmediate reaction; US, United States.
aDirect drug challenges correspond to drug challenges without prior skin tests.
bBase case analyses results.
cSum of costs involving (1) performance of penicillin allergy tests and (2) consequences (as expressed in monetary units) resulting from healthcare use.
dAn incremental net benefit > 0 indicates that penicillin allergy testing is cost-saving.
eCorresponds to the minimum percentage of patients with negative penicillin allergy testing that needs to be effectively treated as nonallergic so that testing becomes cost-saving (incremental net benefit > 0).
fCorresponds to the minimum percentage of patients with negative penicillin allergy testing that needs to be effectively treated as nonallergic so that at least half of simulations performed by probabilistic sensitivity analysis identify penicillin allergy testing as cost-saving.