Table 2.
Diagnostic performance of D-dimer in patients with suspected DVT (N = 444) according to age groups.
| Age < 60 years | Age ≥ 60 years | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| No. DVT | Sensitivity [%] | Specificity [%] | PPV [%] | NPV [%] | No. DVT | Sensitivity [%] | Specificity [%] | PPV [%] | NPV [%] | ||
| Total sample | 92/224 | 76.1 (66.1/84.4) | 40.9 (32.4/49.8) | 47.3 (39.0/55.7) | 71.1 (59.5/80.9) | 112/220 | 92.9 (86.4/96.9) | 13.0 (7.3/20.08) | 52.5 (45.3/59.6) | 63.6 (40.7/82.8) | |
| Sex | Male | 50/95 | 82.0 (68.6/91.4) | 37.8 (23.8/53.5) | 59.4 (46.9/71.1) | 65.4 (44.3/82.8) | 64/105 | 95.3 (86.9/99.0) | 17.1 (7.2/32.1) | 64.2 (53.7/73.8) | 70.0 (34.8/93.3) |
| Female | 42/129 | 69.0 (52.9/82.4) | 42.5 (32.0/53.6) | 36.7 (26.1/48.3) | 74.0 (59.7/85.4) | 48/115 | 89.6 (77.3/96.5) | 10.4 (4.3/20.3) | 41.7 (32.1/51.9) | 58.3 (27.7/84.8) | |
| Aetiology | Unprovoked | 42/174 | 69.0 (52.9/82.4) | 40.9 (32.4/49.8) | 27.1 (19.0/36.6) | 80.6 (69.1/89.2) | 44/152 | 90.9 (78.3/97.5) | 13.0 (7.3/20.8) | 29.9 (22.3/38.4) | 77.8 (52.4/93.6) |
| Provoked | 47/179 | 83.0 (69.2/92.4) | 40.9 (32.4/49.8) | 33.3 (24.9/42.6) | 87.1 (76.1/94.3) | 67/175 | 94.0 (85.4/98.3) | 13.0 (7.3/20.8) | 40.1 (32.4/48.2) | 77.8 (52.4/93.6) | |
| Number of segments with thrombi | 1 | 54/186 | 61.1 (46.9/74.1) | 40.9 (32.4/49.8) | 29.7 (21.4/39.1) | 72.0 (60.4/81.8) | 72/180 | 90.3 (81.0/96.0) | 13.0 (7.3/20.8) | 40.9 (33.2/48.9) | 66.7 (43.0/85.4) |
| ≥2 | 38/170 | 97.4 (86.2/99.9) | 40.9 (32.4/49.8) | 32.2 (23.8/41.5) | 98.2 (90.3/100) | 40/148 | 97.5 (86.8/99.9) | 13.0 (7.3/20.8) | 29.3 (21.8/37.8) | 93.3 (68.1/99.8) | |
| Pretest probability | Low-to-moderate | 71/195 | 73.2 (61.4/83.1) | 41.1 (32.4/50.3) | 41.6 (32.9/50.8) | 72.9 (60.9/82.8) | 90/179 | 94.4 (87.5/98.2) | 13.5 (7.2/22.4) | 52.5 (44.5/60.4) | 70.6 (44.4/89.7) |
| High | 21/29 | 85.7 (63.7/97.0) | 37.5 (8.5/75.5) | 78.3 (56.3/92.5) | 50.0 (11.8/88.2) | 22/40 | 86.4 (65.1/97.1) | 11.1 (1.4/34.7) | 54.3 (36.6/71.2) | 40.0 (5.3/85.3) | |
| Site | Proximal | 46/178 | 91.3 (79.2/97.6) | 40.9 (32.4/49.8) | 35.0 (26.5/44.2) | 93.1 (83.3/98.1) | 49/157 | 98.0 (89.1/99.9) | 13.0 (7.3/20.8) | 33.8 (26.1/42.2) | 93.3 (68.1/99.8) |
| Isolated distal | 46/178 | 60.9 (45.4/74.9) | 40.9 (32.4/49.8) | 26.4 (18.3/35.9) | 75.0 (63.4/84.5) | 63/171 | 88.9 (78.4/95.4) | 13.0 (7.3/20.8) | 37.3 (29.6/45.6) | 66.7 (43.0/85.4) | |
Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) are provided as relative frequency with according 95% confidence interval for a D-dimer threshold of 0.5 mg/L FEU. Absolute frequency (no.) of DVT cases is denoted for all subgroups. Reference group for the stratified analysis of DVT cases by aetiology, site, and number of venous segments with thrombotic material was patients without DVT. Classification of pre-test probability: low-to-moderate: Wells score 0–2; high: Wells score > 2. DVT, deep vein thrombosis.