Table 3.
Overall and covariate analysis for D-dimer testing stratified by use of conventional and age adjusted cut-off levels in patients with a non-high clinical probability of venous thromboembolism (all age categories except <50 years)
| Analyses | No of cohorts | Sensitivity (95% CI) | Specificity (95% CI) | |||
|---|---|---|---|---|---|---|
| Conventional cut-off (%) | Age adjusted cut-off (%) | Conventional cut-off (%) | Age adjusted cut-off (%) | |||
| Overall analyses: age-categories >50 years | 13 | 99.3 (98.4 to 99.7) | 97.8 (95.9 to 98.9) | 36.1 (30.8 to 41.7) | 48.8 (42.9 to 54.7) | |
| Prevalence in cohort (overall): | ||||||
| <23% | 7 | 99.4 (98.2 to 99.8) | 97.9 (95.3 to 99.1) | 37.5 (30.4 to 45.2) | 49.9 (42.0 to 57.7) | |
| >23% | 6 | 99.1 (97.0 to 99.7) | 97.7 (94.2 to 99.1) | 34.2 (26.7 to 42.5) | 47.8 (39.1 to 56.5) | |
| P value | — | 0.64 | 0.89 | 0.56 | 0.73 | |
| D-dimer assay: | ||||||
| Only ELFA | 3 | 100 (NA) | 99.6 (98.2 to 99.9) | 28.69 (20.6 to 38.5) | 40.8 (30.8 to 51.7) | |
| Quantitative latex assay (and ELFA)† | 10 | 98.7 (97.5 to 99.3) | 96.4 (94.6 to 97.6) | 35.6 (32.9 to 42.5) | 51.3 (45.2 to 57.4) | |
| P value | — | 0.97 | 0.005 | 0.08 | 0.10 | |
| Clinical suspicion: | ||||||
| Pulmonary embolism | 7 | 99.2 (97.9 to 99.7) | 97.5 (94.7 to 98.8) | 34.0 (27.7 to 40.9) | 45.7 (38.5 to 53.1) | |
| Deep vein thrombosis | 6 | 99.8 (97.8 to 99.97) | 99.3 (96.6 to 99.8) | 36.0 (34.0 to 38.0) | 48.0 (45.8 to 50.2) | |
| P value | — | 0.31 | 0.15 | 0.58 | 0.55 | |
ELFA=enzyme linked fluorescent assay; NA=not applicable.
*Covariate analysis for setting was not possible as only one study was performed in primary care.
†This stratum contains studies wherein quantitative latex agglutination assays were used, or latex agglutination assays indifferently with ELFA assays.