The natural history of Chlamydia trachomatis infection in women: a multi-parameter evidence synthesis
Background and objectives: The evidence base supporting the National Chlamydia Screening Programme, initiated in 2003, has been questioned repeatedly, with little consensus on modelling assumptions, parameter values or evidence sources to be used in cost-effectiveness analyses. The purpose of this p...
| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | English |
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NIHR Journals Library
2016-03-01
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| Series: | Health Technology Assessment |
| Subjects: | |
| Online Access: | https://doi.org/10.3310/hta20220 |
| _version_ | 1828401147940962304 |
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| author | Malcolm J Price AE Ades Kate Soldan Nicky J Welton John Macleod Ian Simms Daniela DeAngelis Katherine ME Turner Paddy J Horner |
| author_facet | Malcolm J Price AE Ades Kate Soldan Nicky J Welton John Macleod Ian Simms Daniela DeAngelis Katherine ME Turner Paddy J Horner |
| author_sort | Malcolm J Price |
| collection | DOAJ |
| description | Background and objectives: The evidence base supporting the National Chlamydia Screening Programme, initiated in 2003, has been questioned repeatedly, with little consensus on modelling assumptions, parameter values or evidence sources to be used in cost-effectiveness analyses. The purpose of this project was to assemble all available evidence on the prevalence and incidence of Chlamydia trachomatis (CT) in the UK and its sequelae, pelvic inflammatory disease (PID), ectopic pregnancy (EP) and tubal factor infertility (TFI) to review the evidence base in its entirety, assess its consistency and, if possible, arrive at a coherent set of estimates consistent with all the evidence. Methods: Evidence was identified using ‘high-yield’ strategies. Bayesian Multi-Parameter Evidence Synthesis models were constructed for separate subparts of the clinical and population epidemiology of CT. Where possible, different types of data sources were statistically combined to derive coherent estimates. Where evidence was inconsistent, evidence sources were re-interpreted and new estimates derived on a post-hoc basis. Results: An internally coherent set of estimates was generated, consistent with a multifaceted evidence base, fertility surveys and routine UK statistics on PID and EP. Among the key findings were that the risk of PID (symptomatic or asymptomatic) following an untreated CT infection is 17.1% [95% credible interval (CrI) 6% to 29%] and the risk of salpingitis is 7.3% (95% CrI 2.2% to 14.0%). In women aged 16–24 years, screened at annual intervals, at best, 61% (95% CrI 55% to 67%) of CT-related PID and 22% (95% CrI 7% to 43%) of all PID could be directly prevented. For women aged 16–44 years, the proportions of PID, EP and TFI that are attributable to CT are estimated to be 20% (95% CrI 6% to 38%), 4.9% (95% CrI 1.2% to 12%) and 29% (95% CrI 9% to 56%), respectively. The prevalence of TFI in the UK in women at the end of their reproductive lives is 1.1%: this is consistent with all PID carrying a relatively high risk of reproductive damage, whether diagnosed or not. Every 1000 CT infections in women aged 16–44 years, on average, gives rise to approximately 171 episodes of PID and 73 of salpingitis, 2.0 EPs and 5.1 women with TFI at age 44 years. Conclusions and research recommendations: The study establishes a set of interpretations of the major studies and study designs, under which a coherent set of estimates can be generated. CT is a significant cause of PID and TFI. CT screening is of benefit to the individual, but detection and treatment of incident infection may be more beneficial. Women with lower abdominal pain need better advice on when to seek early medical attention to avoid risk of reproductive damage. The study provides new insights into the reproductive risks of PID and the role of CT. Further research is required on the proportions of PID, EP and TFI attributable to CT to confirm predictions made in this report, and to improve the precision of key estimates. The cost-effectiveness of screening should be re-evaluated using the findings of this report. Funding: The Medical Research Council grant G0801947. |
| first_indexed | 2024-12-10T09:43:00Z |
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| institution | Directory Open Access Journal |
| issn | 1366-5278 2046-4924 |
| language | English |
| last_indexed | 2024-12-10T09:43:00Z |
| publishDate | 2016-03-01 |
| publisher | NIHR Journals Library |
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| series | Health Technology Assessment |
| spelling | doaj.art-5cba4b4a87454b9e9416cafa008336bc2022-12-22T01:53:56ZengNIHR Journals LibraryHealth Technology Assessment1366-52782046-49242016-03-01202210.3310/hta2022006/98/02The natural history of Chlamydia trachomatis infection in women: a multi-parameter evidence synthesisMalcolm J Price0AE Ades1Kate Soldan2Nicky J Welton3John Macleod4Ian Simms5Daniela DeAngelis6Katherine ME Turner7Paddy J Horner8Institute of Applied Health Research, University of Birmingham, Birmingham, UKSchool of Social and Community Medicine, University of Bristol, Bristol, UKPublic Health England (formerly Health Protection Agency), Colindale, London, UKSchool of Social and Community Medicine, University of Bristol, Bristol, UKSchool of Social and Community Medicine, University of Bristol, Bristol, UKPublic Health England (formerly Health Protection Agency), Colindale, London, UKPublic Health England (formerly Health Protection Agency), Colindale, London, UKSchool of Social and Community Medicine, University of Bristol, Bristol, UKSchool of Social and Community Medicine, University of Bristol, Bristol, UKBackground and objectives: The evidence base supporting the National Chlamydia Screening Programme, initiated in 2003, has been questioned repeatedly, with little consensus on modelling assumptions, parameter values or evidence sources to be used in cost-effectiveness analyses. The purpose of this project was to assemble all available evidence on the prevalence and incidence of Chlamydia trachomatis (CT) in the UK and its sequelae, pelvic inflammatory disease (PID), ectopic pregnancy (EP) and tubal factor infertility (TFI) to review the evidence base in its entirety, assess its consistency and, if possible, arrive at a coherent set of estimates consistent with all the evidence. Methods: Evidence was identified using ‘high-yield’ strategies. Bayesian Multi-Parameter Evidence Synthesis models were constructed for separate subparts of the clinical and population epidemiology of CT. Where possible, different types of data sources were statistically combined to derive coherent estimates. Where evidence was inconsistent, evidence sources were re-interpreted and new estimates derived on a post-hoc basis. Results: An internally coherent set of estimates was generated, consistent with a multifaceted evidence base, fertility surveys and routine UK statistics on PID and EP. Among the key findings were that the risk of PID (symptomatic or asymptomatic) following an untreated CT infection is 17.1% [95% credible interval (CrI) 6% to 29%] and the risk of salpingitis is 7.3% (95% CrI 2.2% to 14.0%). In women aged 16–24 years, screened at annual intervals, at best, 61% (95% CrI 55% to 67%) of CT-related PID and 22% (95% CrI 7% to 43%) of all PID could be directly prevented. For women aged 16–44 years, the proportions of PID, EP and TFI that are attributable to CT are estimated to be 20% (95% CrI 6% to 38%), 4.9% (95% CrI 1.2% to 12%) and 29% (95% CrI 9% to 56%), respectively. The prevalence of TFI in the UK in women at the end of their reproductive lives is 1.1%: this is consistent with all PID carrying a relatively high risk of reproductive damage, whether diagnosed or not. Every 1000 CT infections in women aged 16–44 years, on average, gives rise to approximately 171 episodes of PID and 73 of salpingitis, 2.0 EPs and 5.1 women with TFI at age 44 years. Conclusions and research recommendations: The study establishes a set of interpretations of the major studies and study designs, under which a coherent set of estimates can be generated. CT is a significant cause of PID and TFI. CT screening is of benefit to the individual, but detection and treatment of incident infection may be more beneficial. Women with lower abdominal pain need better advice on when to seek early medical attention to avoid risk of reproductive damage. The study provides new insights into the reproductive risks of PID and the role of CT. Further research is required on the proportions of PID, EP and TFI attributable to CT to confirm predictions made in this report, and to improve the precision of key estimates. The cost-effectiveness of screening should be re-evaluated using the findings of this report. Funding: The Medical Research Council grant G0801947.https://doi.org/10.3310/hta20220chlamydia trachomatisnatural historyinfectionwomenmulti-parameter evidence synthesispelvic inflammatory diseaseectopic pregnancyinfertility |
| spellingShingle | Malcolm J Price AE Ades Kate Soldan Nicky J Welton John Macleod Ian Simms Daniela DeAngelis Katherine ME Turner Paddy J Horner The natural history of Chlamydia trachomatis infection in women: a multi-parameter evidence synthesis Health Technology Assessment chlamydia trachomatis natural history infection women multi-parameter evidence synthesis pelvic inflammatory disease ectopic pregnancy infertility |
| title | The natural history of Chlamydia trachomatis infection in women: a multi-parameter evidence synthesis |
| title_full | The natural history of Chlamydia trachomatis infection in women: a multi-parameter evidence synthesis |
| title_fullStr | The natural history of Chlamydia trachomatis infection in women: a multi-parameter evidence synthesis |
| title_full_unstemmed | The natural history of Chlamydia trachomatis infection in women: a multi-parameter evidence synthesis |
| title_short | The natural history of Chlamydia trachomatis infection in women: a multi-parameter evidence synthesis |
| title_sort | natural history of chlamydia trachomatis infection in women a multi parameter evidence synthesis |
| topic | chlamydia trachomatis natural history infection women multi-parameter evidence synthesis pelvic inflammatory disease ectopic pregnancy infertility |
| url | https://doi.org/10.3310/hta20220 |
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