Flow chart of the selection of the study population.

<p>Flow chart of the selection of the study population.</p

Characteristics and positivity of 87 tested peers, concordance with the 87 indices that gave them the test.

<p>^{^}percentages were calculated excluding missing information for 18 indices that did not provide information as they were untested</p><p>Characteristics and positivity of 87 tested peers, concordance with the 87 indices that gave them the test.</p

Number of test requests and tests by Chlamydia negative and positive indices.

<p>Number of test requests and tests by Chlamydia negative and positive indices.</p

<i>Chlamydia trachomatis</i> (CT) peer testing and associated factors among 369 indices who requested a CT test for themselves and got an extra test for a peer, and positivity among tested peers.

<p>CI: Confidence Interval; aOR: adjusted Odds Ratio, meaning that risk estimates were adjusted when applicable for initial screening result of the index, years of age of the index, sex of the index, timing of the screening test of the index, and whether the index retested.</p><p>*p<0.05</p><p>^{^}nationality was not included as a factor as nearly all participants had Dutch nationality</p><p>^# reported at retesting of the index</p><p><i>Chlamydia trachomatis</i> (CT) peer testing and associated factors among 369 indices who requested a CT test for themselves and got an extra test for a peer, and positivity among tested peers.</p

Proportion of test requests, returns, overall testing and <i>Chlamydia trachomatis</i> (CT) positivity and associated factors in1072 young people invited by SMS for a retest.

<p>*p<0.05,</p><p>^# p<0.10</p><p>CI: Confidence Interval; aOR: adjusted Odds Ratio, meaning that risk estimates were adjusted when applicable for initial screening result of the index, age of the index, sex of the index, timing of the screening test of the index</p><p>^{^}nationality was not included as a factor as nearly all participants had Dutch nationality</p><p>Proportion of test requests, returns, overall testing and <i>Chlamydia trachomatis</i> (CT) positivity and associated factors in1072 young people invited by SMS for a retest.</p

Perpetrator of NVS by assault and NVS by penetration in most recent occurrence.

<p>Perpetrator of NVS by assault and NVS by penetration in most recent occurrence.</p

Poisson regression models for pertussis testing, stratified by age.

<p>Significance levels: * = 0.05; ** = 0.01; *** = 0.001. Only significant predictors are reported.</p

Is the current pertussis incidence only the results of testing? A spatial and space-time analysis of pertussis surveillance data using cluster detection methods and geographically weighted regression modelling - Fig 1

<p>Spatial distribution of a) pertussis testing, b) incidence and c) test-positivity, 2007–2013.</p

Significant (p<0.05) coefficients per HCV cluster for model 1.

<p>Significant (p<0.05) coefficients per HCV cluster for model 1.</p

Results of the geographically weighted Poisson regression of pertussis incidence among the total population.

<p>Results of the geographically weighted Poisson regression of pertussis incidence among the total population.</p