Understanding relationships between chlamydial infection, symptoms and testing behavior: an analysis of data from Natsal-3
File(s)
Published version
Author(s)
Lewis, Joanna
White, Peter J
Type
Journal Article
Abstract
Background: Genital chlamydial infection is the most commonly-diagnosed sexually- transmitted infection worldwide, and can have serious long-term sequelae. Numerous countries invest substantially in testing but evidence for programs’ effectiveness is inconclusive. The effects of testing programs in different groups of people need to be understood. Methods: We analyzed data on sexual behavior and chlamydia testing from 16-24-year-olds in Britain’s third National Survey of Sexual Attitudes and Lifestyles, considering test setting, reason and result. We conducted descriptive analysis accounting for the survey design using design variables and nonresponse weightings, and Bayesian analysis using a mathematical model of chlamydial infection and testing. Results: Most men testing due to symptoms tested in sexual health settings (63.1%; 95% confidence interval 42.5-83.6%) but most women testing due to symptoms were tested by GPs (59.3%; 42.9-75.8%). Within behavioral groups, positivity of chlamydia screens (tests not prompted by symptoms or partner notification) was similar to population prevalence. Screening rates were higher in women and in those reporting more partners: median (95% credible interval) rates per year in those reporting 0, 1 and ≥2 new partners in the last year were 0.30(0.24-0.35), 0.45(0.37-0.53) and 0.59(0.48-0.71) (men) and 0.59(0.52-0.68), 0.88(0.74-1.03) 20 and 1.16(0.97-1.39) (women). Conclusions: The proportion of testing occurring in sexual health is not a proxy for the proportion prompted by symptoms. Test positivity depends on a combination of force of infection and screening rate and does not simply reflect prevalence or behavioral risk. The analysis highlights the value of recording testing reason and behavioral characteristics to inform cost-effective control.
Date Issued
2020-03
Date Acceptance
2019-08-01
Citation
Epidemiology, 2020, 31 (2), pp.263-271
ISSN
1044-3983
Publisher
Lippincott, Williams & Wilkins
Start Page
263
End Page
271
Journal / Book Title
Epidemiology
Volume
31
Issue
2
Copyright Statement
© 2019 The Author(s). Published by Wolters Kluwer Health, Inc.
This is an open access article distributed under the Creative Commons
Attribution License 4.0 (CCBY), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is
properly cited.
This is an open access article distributed under the Creative Commons
Attribution License 4.0 (CCBY), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is
properly cited.
Sponsor
National Institute for Health Research
Medical Research Council (MRC)
Identifier
https://journals.lww.com/epidem/FullText/2020/03000/Understanding_Relationships_Between_Chlamydial.15.aspx
Grant Number
HPRU-2012-10080
MR/R015600/1
Subjects
Epidemiology
0104 Statistics
1117 Public Health and Health Services
Publication Status
Published online
Date Publish Online
2019-11-25