Table 2

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
NumberConcordant (% 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
All646249 (39%)77 (12%)325 (50%)4.2 (3.3 to 5.2)**
Extended concordance646559 (87%)11 (2.0%)81 (13%)7.4 (4.0 to 14)**
Women with BV excluded575211 (37%)55 (10%)309 (54%)5.6 (4.3 to 7.3)**
Coarse-type LB excluded472162 (34%)68 (14%)242 (51%)3.6 (2.8 to 4.5)**
(B) Wet mount compared with fresh Gram stained specimen
All238103 (43%)35 (15%)100 (42%)2.9 (2.0 to 4.0)**
Extended concordance238217 (91%)7 (3%)14 (6%)2.0 (0.8 to 4.9)
Women with BV excluded21991 (42%)28 (13%)100 (46%)3.6 (2.5 to 5.2)**
Coarse-type LB excluded18386 (47%)27 (15%)70 (38%)2.5 (1.7 to 3.8)*