Concordance and discordance rates comparing wet mount with Gram stained specimens (A) after transport of the specimen in Stuart's medium (n = 646) and (B) in a subgroup comparing wet mount with fresh Gram stain (n = 238) in patients with or without bacterial vaginosis
| Discordant | |||||
|---|---|---|---|---|---|
| Number | Concordant (% of total) | Lower LBG on Gram (% of total) | Higher LBG on Gram (% of total) | Relative risk of higher LBG in Gram (95% CL) | |
| “Extended concordance”: the grade allocated by one technique differs maximally one level from, or is equal to, the grade allocated by the other technique. | |||||
| *p < 0.01; **p < 0.0001 (χ2 test). | |||||
| BV, bacterial vaginosis; CL, confidence limits; LB, lactobacillary morphotype; LBG, lactobacillary grades. | |||||
| (A) Wet mount compared with delayed Gram stained specimen | |||||
| All | 646 | 249 (39%) | 77 (12%) | 325 (50%) | 4.2 (3.3 to 5.2)** |
| Extended concordance | 646 | 559 (87%) | 11 (2.0%) | 81 (13%) | 7.4 (4.0 to 14)** |
| Women with BV excluded | 575 | 211 (37%) | 55 (10%) | 309 (54%) | 5.6 (4.3 to 7.3)** |
| Coarse-type LB excluded | 472 | 162 (34%) | 68 (14%) | 242 (51%) | 3.6 (2.8 to 4.5)** |
| (B) Wet mount compared with fresh Gram stained specimen | |||||
| All | 238 | 103 (43%) | 35 (15%) | 100 (42%) | 2.9 (2.0 to 4.0)** |
| Extended concordance | 238 | 217 (91%) | 7 (3%) | 14 (6%) | 2.0 (0.8 to 4.9) |
| Women with BV excluded | 219 | 91 (42%) | 28 (13%) | 100 (46%) | 3.6 (2.5 to 5.2)** |
| Coarse-type LB excluded | 183 | 86 (47%) | 27 (15%) | 70 (38%) | 2.5 (1.7 to 3.8)* |