Evidence on the Benefits and Harms of Screening and Treating Pregnant Women Who Are Asymptomatic for Bacterial Vaginosis: An Update Review. Table 2

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Table 2. Outcomes Table: Benefits and Harms of Screening 1000 Pregnant Women at High Risk for Bacterial Vaginosis^a

Benefit and Relevant Factors	General High-Risk Group (95% CI)^b	More Selected High-Risk Group (95% CI)^c
Assumptions and estimates
Prevalence of bacterial vaginosis in population	0.25	0.25
Sensitivity of screening test	0.95	0.95
Specificity of screening test	0.95	0.95
Adherence to treatment	0.80	0.80
Effect sizes in patients with bacterial vaginosis^d
Delivery <37 weeks	-0.125 (-0.239 to -0.010)^50,57,e	+0.229 (+0.118 to +0.339)^58-60,e
Preterm, premature rupture of membranes	-0.036 (-0.114 to +0.042)^57,e	+0.237 (+0.115 to +0.360)^58,59,e
Delivery <34 weeks	-0.033 (-0.126 to +0.060)^50,57,e	+0.079 (-0.026 to +0.183)^58,59,e
Effect sizes in patients without bacterial vaginosis^d
Delivery <37 weeks	0.00	0.00
Preterm premature rupture of membranes	0.00	0.00
Delivery <34 weeks	-0.02	-0.06
Results, n
Unsuspected bacterial vaginosis	250	250
No bacterial vaginosis	750	750
Correctly diagnosed as having bacterial vaginosis	238	238
Has bacterial vaginosis and has completed therapy	190	190
Incorrectly diagnosed as having bacterial vaginosis	38	38
No bacterial vaginosis and has completed therapy	30	30
Has bacterial vaginosis and missed or did not complete therapy	60	60
Outcomes
Delivery <37 weeks	-24 (-45 to -2)	+44 (+22 to +64)
Preterm, premature rupture of membranes	-7 (-22 to +8)	+45 (+22 to +68)
Delivery <34 weeks	-7 (-25 to +11)	+13 (-7 to +33)

^a. The proportion of all patients who meet the criteria for high risk varies with practice setting, patient population, and the criteria used to define high risk. A negative sign (-) indicates a net increase in adverse outcomes (harm), whereas a positive sign (+) indicates a net decrease in adverse outcomes (benefit).
^b. Preterm delivery baseline risk <30%.
^c. Preterm delivery baseline risk >30%.
^d. Probability in control group—probability in treated group.
^e. We used effect size data from high-risk studies where available for specific outcomes.

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Table 2. Outcomes Table: Benefits and Harms of Screening 1000 Pregnant Women at High Risk for Bacterial Vaginosisa

Table 2. Outcomes Table: Benefits and Harms of Screening 1000 Pregnant Women at High Risk for Bacterial Vaginosis^a