Systematic selection of screening participants by risk score in a chlamydia screening programme is feasible and effective

Abstract

Objectives Systematic screening for Chlamydia trachomatis by individual invitation can be optimised by filtering participants on risk profile, excluding people at no or low risk. The authors investigated this technique in a large-scale chlamydia screening programme in the Netherlands in one rural region where relatively low prevalence was expected (<2%). Methods Invitees were alerted by personal letter to log in to http://www.chlamydiatest.nl and fill in an 8-item questionnaire. Only invitees with sufficient score could proceed to request a test kit. The authors investigated the effect of selection on participation, positivity and acceptability in three screening rounds and on the number needed to invite and the number needed to screen. Results The selection led to exclusion of 36% of potential participants and a positivity rate of 4.8% among participants, achieving similar number needed to screen values in the rural and urban areas. Higher scores were clearly related to higher positivity rates. Persons who were excluded from participation did not have a lower response in the next round. The acceptability study revealed disappointment about exclusion of 30% of excluded participants but most approved of the screening set-up. Conclusions Systematic selection of screening participants by risk score is feasible and successful in realising higher positivity rates. A somewhat stricter selection could be applied in the rural and urban areas of the screening programme. Multiple-item selection with a cut-off total score may work better than, more commonly used, selection by single criteria, especially in low-risk populations. Acceptability of selection is high but could still be improved by better communication on expectations.

Deriving and Validating A Risk Estimation Tool for Screening Asymptomatic Chlamydia and Gonorrhea

“…This may enable clinicians to effectively determine whether triaging those with low-risk scores to receive "express" services (e.g., providing self-collected specimens) or referring others to more comprehensive services (e.g., complete physical examinations). 8 This process may help decrease wait times, improve clinical workflow, and reduce unnecessary clinician face time.…”

“…7 To maximize case finding in asymptomatic visits, selective screening (based on risk assessment and entails the screening of individuals who meet prespecified criteria) may be a prudent approach because it minimizes the costs associated with testing low-risk individuals. 8 The current body of knowledge indicates that risk prediction rules that capture a continuous risk spectrum are excellent tools for targeted screening. 9 A recent review critically appraising prediction rules used for sexual health service provision found that these have been explored in a variety of contexts including emergency departments, population-based settings and STI clinics.…”

Prediction ofChlamydia trachomatisinfection to facilitate selective screening on population and individual level: a cross-sectional study of a population-based screening programme

“…The score charts may be useful to select high-risk individuals as part of systematic screening programmes in urban areas, similar to the selection of individuals at high risk in less urban regions 10. Furthermore, the score charts may be used in guiding STI clinicians and GPs whom to offer opportunistic Ct testing—more selectively than using age group alone.…”

It matters what you measure: a systematic literature review examining whether young people in poorer socioeconomic circumstances are more at risk of chlamydia

“…A screening programme trialled in the Netherlands used information on young people's SEC to exclude those with low or no risk of chlamydia. The researchers concluded that this selective approach achieved higher positivity in their population compared with screening all young people 10. However, a more recent systematic review to examine socioeconomic associations with chlamydia concluded that the relationship is unclear and called for more research to build a ‘deeper understanding’ of chlamydia's relationship with social factors 11.…”