TABLE 4.
Method | Country and experience (no. of laboratories) | VME rate (% [no. of VMEs/total no. resistant]) | Sensitivity (95% CI) | ME rate (% [no. of MEs/total no. susceptible]) | Specificity (95% CI) |
---|---|---|---|---|---|
Disk diffusion | Sweden (10) | 1.9 (5/270) | 0.98 (0.95–0.99) | 0 (0/30) | 1 (0.86–1) |
Norway (13) | 10 (36/351) | 0.90 (0.86–0.93) | 2.6 (1/39) | 0.97 (0.85–1) | |
Denmark (5) | 8.9 (12/135) | 0.91 (0.85–0.95) | 6.7 (1/15) | 0.93 (0.66–1) | |
Experienced (13) | 2.6 (9/351) | 0.97 (0.95–0.99) | 0 (0/39) | 1 (0.89–1) | |
Inexperienced (15) | 11 (44/405) | 0.89 (0.86–0.92) | 4.4 (2/45) | 0.96 (0.84–0.99) | |
Agar screen | Sweden (1) | 3.7 (1/27) | 0.9 (0.79–1) | 0 (0/3) | 1 (0.31–1) |
Norway (13) | 6.8 (24/351) | 0.93 (0.90–0.95) | 0 (0/39) | 1 (0.89–1) | |
Denmark (4) | 6.5 (7/108) | 0.94 (0.87–0.97) | 25 (3/12) | 0.75 (0.43–0.93) | |
Experienced (13) | 6.8 (24/351) | 0.93 (0.90–0.95) | 0 (0/39) | 1 (0.89–1) | |
Inexperienced (5) | 5.9 (8/135) | 0.94 (0.88–0.97) | 20 (3/15) | 0.8 (0.51–0.95) |
In VMEs, strains were classified as susceptible when containing the van genotype. In MEs, strains were classified as resistant when containing no van genotype.