GRADE test accuracy evidence summary for VWF:RCo in patients with suspected VWD
| Sensitivity: 0.83-1.00 Specificity: 0.87-0.95 | Prevalences: 3%, 20%, 50% |
| Sensitivity: 0.83-1.00 Specificity: 0.87-0.95 | Prevalences: 3%, 20%, 50% |
| Outcome . | Studies (n); patients (n) . | Study design . | Factors that may decrease certainty of evidence . | Effect per 1000 patients tested . | Test accuracy CoE . | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Risk of bias . | Indirectness . | Inconsistency . | Imprecision . | Publication bias . | Pretest probability of 3%* . | Pretest probability of 20%† . | Pretest probability of 50%§ . | ||||
| True positives (patients with VWD) | 4;337 | Cohort & case-control type studies | Serious‡ | Not serious | Not serious | Not serious | None | 25-30 | 166-200 | 415-500 | ⨁⨁⨁◯ MODERATE |
| False negatives (patients incorrectly classified as not having VWD) | 0-5 | 0-34 | 0-85 | ||||||||
| True negatives (patients without VWD) | 4;584 | Cohort & case-control type studies | Serious‡ | Not serious | Not serious | Not serious | None | 844-922 | 696-760 | 435-475 | ⨁⨁◯◯ LOW |
| False positives (patients incorrectly classified as having VWD) | 48-126 | 40-104 | 25-65 | ||||||||
| Outcome . | Studies (n); patients (n) . | Study design . | Factors that may decrease certainty of evidence . | Effect per 1000 patients tested . | Test accuracy CoE . | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Risk of bias . | Indirectness . | Inconsistency . | Imprecision . | Publication bias . | Pretest probability of 3%* . | Pretest probability of 20%† . | Pretest probability of 50%§ . | ||||
| True positives (patients with VWD) | 4;337 | Cohort & case-control type studies | Serious‡ | Not serious | Not serious | Not serious | None | 25-30 | 166-200 | 415-500 | ⨁⨁⨁◯ MODERATE |
| False negatives (patients incorrectly classified as not having VWD) | 0-5 | 0-34 | 0-85 | ||||||||
| True negatives (patients without VWD) | 4;584 | Cohort & case-control type studies | Serious‡ | Not serious | Not serious | Not serious | None | 844-922 | 696-760 | 435-475 | ⨁⨁◯◯ LOW |
| False positives (patients incorrectly classified as having VWD) | 48-126 | 40-104 | 25-65 | ||||||||
Typically seen in patients investigated for VWD because of a personal history of bleeding symptoms (eg, mucocutaneous bleeding) (Quiroga, 2007).46
Typically seen in patients investigated for VWD as a first-degree relative of a patient with VWD.
Serious patient selection risk of bias due to case-control design. Also, 3 of the 4 studies (Boender [2018],47 Vangenechten [2018],48 and Sagheer [2016])49 investigated test accuracy for classifying type 2 VWD patients (using a ratio of 0.6), not for diagnosing VWD. The majority of included studies were judged to be low risk of bias for test and reference standard interpretation. Although there was unclear reporting regarding flow and timing in some studies, the certainty of evidence was generally not downgraded for risk of bias. The patient selection risk of bias was moderate/high in all studies.
Typically seen in patients investigated for VWD because of a personal history of abnormal laboratory test (eg, increased Partial Thromboplastin Time (PTT)).