Heterogeneity in risk of pelvic inflammatory diseases after Chlamydia infection: a population-based study in manitoba, Canada

Bethan Davies, Helen Ward, Stella Leung, Katy M E Turner, Geoff P Garnett, James F Blanchard, B Nancy Yu

Research output: Contribution to journalArticle (Academic Journal)peer-review

21 Citations (Scopus)


BACKGROUND: The association between chlamydia infection and pelvic inflammatory disease (PID) is a key parameter for models evaluating the impact of chlamydia control programs. We quantified this association using a retrospective population-based cohort.

METHODS: We used administrative health data sets to construct a retrospective population-based cohort of women and girls aged 12-24 years who were resident in Manitoba, Canada, between 1992 and 1996. We performed survival analysis on a subcohort of individuals who were tested for chlamydia to estimate the risk of PID diagnosed in a primary care, outpatient, or inpatient setting after ≥1 positive chlamydia test.

RESULTS: A total of 73 883 individuals contributed 625 621 person years of follow-up. Those with a diagnosis of chlamydia had an increased risk of PID over their reproductive lifetime compared with those who tested negative (adjusted hazard ratio [AHR], 1.55; 95% confidence interval [CI], 1.43-1.70). This risk increased with each subsequent infection: the AHR was 1.17 for first reinfection (95% CI, 1.06-1.30) and 1.35 for the second (95% CI, 1.04-1.75). The increased risk of PID from reinfection was highest in younger individuals (AHR, 4.55 (95% CI, 3.59-5.78) in individuals aged 12-15 years at the time of their second reinfection, compared with individuals older than 30 years).

CONCLUSIONS: There is heterogeneity in the risk of PID after a chlamydia infection. Describing the progression to PID in mathematical models as an average rate may be an oversimplification; more accurate estimates of the cost-effectiveness of screening may be obtained by using an individual-based measure of risk. Health inequalities may be reduced by targeting health promotion interventions at sexually active girls younger than 16 years and those with a history of chlamydia.

Original languageEnglish
Pages (from-to)S549-55
JournalJournal of Infectious Diseases
Volume210 Suppl 2
Publication statusPublished - 1 Dec 2014

Bibliographical note

© The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America.


Dive into the research topics of 'Heterogeneity in risk of pelvic inflammatory diseases after Chlamydia infection: a population-based study in manitoba, Canada'. Together they form a unique fingerprint.

Cite this