Table 1. Summary of Evidence^I,1-4

Arrow 1:

Key Questions: Does screening reduce adverse health outcomes?
Nonpregnant women: Evidence code^a: I, II-3
Nonpregnant women: Quality of evidence^b: Good: one randomized controlled trial indicates screening reduces pelvic inflammatory disease.
Pregnant women: Evidence code^a: II-2, II-3
Pregnant women: Quality of evidence^b: Fair: no new studies; 2 studies used in prior recommendations indicate improved birth outcomes when pregnant women are screened and treated, although the control group was based on temporal changes in treatment standards in one key study, differences between cases and controls were not different in another study.
Men: Evidence code^a: III
Men: Quality of evidence^b: Poor: no studies of effectiveness of screening in preventing acute infections or complications.

Arrow 2:

Key Questions: Does screening reduce the prevalence of infection?
Evidence code^a: II-3
Quality of evidence^b: Poor-fair: uncontrolled studies based on time trends after initiation of screening, studies from many populations and settings report declining rates.

Key Questions: Are risk factors useful for selective screening?
Nonpregnant women: Evidence code^a: II-2
Nonpregnant women: Quality of evidence^b: Fair: few studies in low prevalence, community populations, studies agree on age.
Pregnant women: Evidence code^a: III
Pregnant women: Quality of evidence^b: Poor: very few studies based on small populations, descriptive.
Men: Evidence code^a: III
Men: Quality of evidence^b: Poor: subjects mainly from sexually transmitted disease clinics, jail, etc, descriptive.

Key Questions: What screening tests should be performed?
Nonpregnant women: Evidence code^a: II-1
Nonpregnant women: Quality of evidence^b: Fair: many studies about test performance under study conditions, not well tested in large screening populations with low prevalence.
Pregnant women: Evidence code^a: II-1
Pregnant women: Quality of evidence^b: Fair: few studies about test performance under study conditions, not tested in large screening populations.
Men: Evidence code^a: II-1
Men: Quality of evidence^b: Fair: many studies about test performance under study conditions, not well tested in large screening populations with low prevalence.

Arrow 3:

Key Questions: What are the implications of recurrent infection?
Nonpregnant women: Evidence code^a: II-2
Nonpregnant women: Quality of evidence^b: Fair: studies include high-risk subjects, lack of internal control groups, report descriptive data.

^[a]Study design categories (Guide to Clinical Preventive Services56).
^[b]Quality of evidence ratings based on criteria developed by the third U.S. Preventive Services Task Force.
^[I]I: Randomized, controlled trials.
^[1]II-1: Controlled trials without randomization.
^[2]II-2: Cohort or case-control analytic studies.
^[3]II-3: Multiple time series, dramatic uncontrolled experiments.
^[4]III: Opinions of respected authorities, descriptive epidemiology.

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