Table 1

 Population based estimates of chlamydia associated complications

Outcome and study settingRefPeriodPopulationStudy designCasesAge (years)Incidence per 1000 woman years
†Data from city disease registry. Not clear if primary care cases are included. Authors estimated rate of chlamydial pelvic inflammatory disease as 1.7 cases per 1000 woman years.
‡Inpatient episodes only of pelvic inflammatory disease as a result of any cause.
§Hospital cases from hospital registers. All cases ascertained by patient report. Data collected at 1 year after intervention so assumed that each woman contributed 1 woman year of follow up. 45% lost to follow up. Includes pelvic inflammatory disease as a result of any cause.
¶Cases ascertained from health insurance records.
**From record linkage.
Pelvic inflammatory disease
    All womenOverallScreenedUnscreened
    Amsterdam, Netherlands81990Population basedDisease registerHospital†15–444.85....
    South Carolina, USA101996–8Military recruitsCohort studyClinical‡80%<25 at entry..4.65.1
    Aarhus, Denmark111997–8Population basedRandomised trialHospital§16–17 at entry6.52.411.5
All cases§
    Seattle, USA121990–2High risk womenRandomised trialAll cases¶18–34 at entry16.9‡9.621.6
    England and Wales131991–2Population basedCross sectionalPrimary care16–4616.7....
    Women with chlamydia
    Massachussetts, USA141988–1Population basedCohort studyAll cases¶20–29 at entry56.3†....
Ectopic pregnancyOverallChlamydia +Chlamydia -
N Jutland, Denmark151984–2003Population basedCohort studyHospital**15–43 at entry3.58.6