Linked Life Data

15800269

Source:http://linkedlifedata.com/resource/pubmed/id/15800269

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
2005-3-31
pubmed:abstractText
This analysis examined how unmeasured confounding affects estimates of the effectiveness of condoms in preventing sexually transmitted infections. Data were analyzed from a prospective cohort study of 1,122 female sexually transmitted disease clinic patients in Alabama (1992-1995), wherein participants were evaluated for sexually transmitted infections at six 1-month intervals. Associations between condom use and incident gonorrhea and chlamydia infection were compared between case-crossover and cohort analyses. In a case-crossover analysis of 228 follow-up visits ending in gonorrhea/chlamydia ("case intervals") and 743 self-matched follow-up visits not ending in gonorrhea/chlamydia ("noncase intervals") (183 women), consistent condom use without breakage or slippage was associated with significantly reduced risk of infection relative to nonuse (adjusted risk odds ratio = 0.49, 95% confidence interval: 0.26, 0.92). Conversely, a cohort analysis of 245 case intervals and 3,896 noncase intervals (919 women) revealed no significant reduction in infection risk from consistent use of condoms (adjusted risk odds ratio = 0.79, 95% confidence interval: 0.53, 1.17). Dose-response relations between the number of unprotected sex acts and infection were stronger in the case-crossover analysis (p for trend = 0.009) than in the cohort analysis (p for trend = 0.18). These findings suggest that epidemiologic studies confounded by unmeasured differences between condom users and nonusers underestimate condom effectiveness against these infections. The case-crossover method provides an additional technique for reducing unmeasured confounding in studies of condom effectiveness.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0002-9262
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
161
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
765-73
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Application of the case-crossover design to reduce unmeasured confounding in studies of condom effectiveness.
pubmed:affiliation
National Center for Chronic Disease Prevention and Health Promotion, Division of Reproductive Health, Centers for Disease Control and Prevention, Atlanta, GA 30341, USA. dlw7@cdc.gov
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S.