Evaluation design of a systematic, selective, internet-based, Chlamydiascreening implementation in the Netherlands, 2008-2010: implications of first results for the analysis

BMC Infectious Diseases

Research Article

Johannes SA Fennema¹  Rik H Koekenbier¹  Elfi EHG Brouwers²  Christian JPA Hoebe²  Sander M van Ravesteijn³  Hannelore M Götz³  Eline LM Op de Coul⁴  Ingrid VF van den Broek⁴  Jan EAM van Bergen⁵  Eva M de Feijter⁵ 

[1] Cluster of Infectious Diseases, Department of Research, Online Research and Prevention Unit, Amsterdam Health Service, Amsterdam, The Netherlands;Department of Infectious Diseases, South Limburg Public Health Service, Geleen, The Netherlands;Division of Infectious Disease Control, Rotterdam Rijnmond Public Health Service, Rotterdam, The Netherlands;Epidemiology & Surveillance Unit, Centre for Infectious Disease Control, National Institute of Public Health and the Environment, Bilthoven, The Netherlands;STI AIDS Netherlands, Amsterdam, The Netherlands;

关键词: Participation Rate;    Sexually Transmitted Infection;    Chlamydia Trachomatis;    Pelvic Inflammatory Disease;    Chlamydia Screening;   

DOI  :  10.1186/1471-2334-10-89

 received in 2009-09-30, accepted in 2010-04-07,  发布年份 2010

来源: Springer

【 摘 要 】

BackgroundA selective, systematic, Internet-based, Chlamydia Screening Implementation for 16 to 29-year-old residents started in three regions in the Netherlands in April 2008: in the cities of Amsterdam and Rotterdam and a more rural region, South Limburg. This paper describes the evaluation design and discusses the implications of the findings from the first screening round for the analysis. The evaluation aims to determine the effects of screening on the population prevalence of Chlamydia trachomatis after multiple screening rounds.MethodsA phased implementation or 'stepped wedge design' was applied by grouping neighbourhoods (hereafter: clusters) into three random, risk-stratified blocks (A, B and C) to allow for impact analyses over time and comparison of prevalences before and after one or two screening rounds. Repeated simulation of pre- and postscreening Chlamydia prevalences was used to predict the minimum detectable decline in prevalence. Real participation and positivity rates per region, block, and risk stratum (high, medium, and low community risk) from the 1st year of screening were used to substantiate predictions.ResultsThe results of the 1st year show an overall participation rate of 16% of 261,025 invitees and a positivity rate of 4.2%, with significant differences between regions and blocks. Prediction by simulation methods adjusted with the first-round results indicate that the effect of screening (minimal detectable difference in prevalence) may reach significance levels only if at least a 15% decrease in the Chlamydia positivity rate in the cities and a 25% decrease in the rural region after screening can be reached, and pre- and postscreening differences between blocks need to be larger.ConclusionsWith the current participation rates, the minimal detectable decline of Chlamydia prevalence may reach our defined significance levels at the regional level after the second screening round, but will probably not be significant between blocks of the stepped wedge design. Evaluation will also include other aspects and prediction models to obtain rational advice about future Chlamydia screening in the Netherlands.

【 授权许可】

Unknown   
© Broek et al; licensee BioMed Central Ltd. 2010. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.