Effectiveness of yearly, register based screening for chlamydia in the Netherlands: controlled trial with randomised stepped wedge implementation

Abstract

Objective To evaluate the effectiveness of register based, yearly chlamydia screening.Design Controlled trial with randomised stepped wedge implementation in three blocks.Setting Three regions of the Netherlands: Amsterdam, Rotterdam, and South Limburg.Participants 317 304 women and men aged 16-29 years listed on municipal registers at start of trial.Intervention From March 2008 to February 2011, the Chlamydia Screening Implementation programme offered yearly chlamydia screening tests. Postal invitations asked people to use an internet site to request a kit for self collection of samples, which would then be sent to regional laboratories for testing. Treatment and partner notification were done by the general practitioner or at a sexually transmitted infection clinic. Main outcome measuresPrimary outcomes were the percentage of chlamydia tests positive (positivity), percentage of invitees returning a specimen (uptake), and estimated chlamydia prevalence. Secondary outcomes were positivity according to sex, age, region, and sociodemographic factors; adherence to screening invitations; and incidence of self reported pelvic inflammatory disease. ResultsThe participation rate was 16.1% (43 358/269 273) after the first invitation, 10.8% after the second, and 9.5% after the third, compared with 13.0% (6223/48 031) in the control block invited at the end of round two of the intervention. Chlamydia positivity in the intervention blocks at the first invitation was the same as in the control block (4.3%) and 0.2% lower at the third invitation (odds ratio 0.96 (95% confidence interval 0.83 to 1.10)). No substantial decreases in positivity were seen after three screening rounds in any region or sociodemographic group. Among the people who participated three times (2.8% of all invitees), positivity fell from 5.9% to 2.9% (odds ratio 0.49 (0.47 to 0.50)). RESEARCHConclusions There was no statistical evidence of an impact on chlamydia positivity rates or estimated population prevalence from the Chlamydia Screening Implementation programme after three years at the participation levels obtained. The current evidence does not support a national roll out of this register based chlamydia screening programme.Trial registration NTR 3071 (Netherlands Trial Register, www. trialregister.nl). IntroductionChlamydia screening has been promoted as a means of controlling sexual transmission of Chlamydia trachomatis (chlamydia), [1][2][3] which is the most common notifiable infection in some high income countries.1 Before introducing a screening programme there should be evidence from high quality randomised controlled trials that the screening programme is effective in reducing mortality or morbidity. 4 The goals of chlamydia screening are to detect and treat asymptomatic infections, to limit ongoing transmission in the community, and to reduce the incidence of pelvic inflammatory disease.5 Pelvic inflammatory disease results from microorganisms, including C trachomatis, ascending to the upper genital tract and is a strong risk fact...

Who tests whom? A comprehensive overview ofChlamydia trachomatistest practices in a Dutch region among different STI care providers for urogenital, anorectal and oropharyngeal sites in young people: a cross-sectional study

“…It consisted of three screening rounds (from 2008 to 2010) among 16–29 year olds in three Dutch regions, including Parkstad. Details of chlamydia screening have been described elsewhere 5 17. Eligibility for chlamydia testing in Parkstad was dependent on an individual's chlamydia risk score, calculated using an eight-item questionnaire (assessing age, place of residence, education level, condom use at last intercourse, number of lifetime sex contacts, ethnic background, having a new sexual partner in the last six months and symptoms) 18…”

“…In addition to regular STI care as described above, CT screening programmes have been established, such as in the UK and the Netherlands 5 6. Each of these STI care providers or programmes will contribute to CT control, yet a comprehensive assessment of their relative contribution in terms of testing, diagnosis and the populations that they serve is thus far unavailable.…”

Population attributable fraction of pelvic inflammatory disease associated with chlamydia and gonorrhoea: a cross-sectional analysis of Australian sexual health clinic data

“…Success of direct prevention depends on the duration between chlamydia acquisition and PID development, which can be weeks 11 23. Some countries have conducted chlamydia screening or opportunistic testing trials focussing on young asymptomatic adults in community settings and included PID as an outcome measure9 14 24 25 Results from a UK trial (PID incidence in chlamydia-screened (1.3%) vs unscreened (1.9%)) suggested chlamydia screening might reduce PID incidence over 1 year9 while a Dutch trial reported a low 1 year PID incidence (1.9%) that did not alter over time 24. Furthermore, a Swedish population-based cohort found a low cumulative PID incidence (to age 35) (5.6% in women ever chlamydia positive vs 4% in chlamydia negative)26 and concluded the benefits of chlamydia screening may have been overestimated.…”

Testing and screening for chlamydia in general practice: a cross‐sectional analysis

“…Randomised-controlled trials (RCTs) have failed to consistently show a significant benefit from population-based screening programs in chlamydia-related morbidity. [3][4][5][6] Due to the sensitive nature of chlamydia screening and the difficulties with confirming a diagnosis of PID, RCTs have been difficult to perform and analyse. 3 But, chlamydia screening is widely and strongly advocated.…”