Evaluation design of a systematic, selective, internet-based, Chlamydia screening implementation in the Netherlands, 2008-2010: implications of first results for the analysis
Evaluation design of a systematic, selective, internet-based, Chlamydia screening implementation in the Netherlands, 2008-2010: implications of first results for the analysis
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DOI：
10.1186/1471-2334-10-89
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发表时间：
2010-04-07
影响因子：
3.7
通讯作者：
de Coul, Eline L. M. Op
中科院分区：
文献类型：
--
作者：
van den Broek, Ingrid V. F.;Hoebe, Christian J. P. A.;de Coul, Eline L. M. Op
背景：2008年4月，荷兰开始在三个地区--阿姆斯特丹和鹿特丹以及更偏向农村的南林堡--对16至29岁的居民进行有选择、有系统、基于互联网的衣原体筛查。本文描述了评估设计，并讨论了第一轮筛选结果对分析的影响。该评估旨在确定多轮筛查后筛查对沙眼衣原体人群流行率的影响。方法：采用分阶段实施或“阶梯式楔形设计”，将社区(下称：群)分成三个随机的风险分层区(A、B和C)，以便进行随时间的影响分析，并比较筛查前或筛查后的流行率。对筛查前和筛查后衣原体流行率的重复模拟被用来预测可检测到的最小流行率下降。结果：第一年的调查结果显示，261,025名受邀者的总参与率为16%，阳性率为4.2%，不同地区、不同社区之间的实际参与率和阳性率有显著差异。根据第一轮筛查结果调整的模拟方法预测结果表明，只有在筛查后城市和农村地区衣原体阳性率至少下降15%和农村地区下降25%的情况下，筛查效果才可能达到显著水平，筛查前和筛查后的差异需要更大。结论：在目前的参与率下，第二轮筛查后地区水平衣原体流行率的最小可检测下降可能达到我们定义的显著水平，但在分级楔形设计的区组之间可能不会有显著差异。评估还将包括其他方面和预测模型，以获得有关荷兰未来衣原体筛查的合理建议。
Background: A 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.Methods: A 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.Results: The 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.Conclusions: With 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.