Publications
47 results found
Ensor S, Davies B, Rai T, et al., 2019, The effectiveness of demand creation interventions for voluntary male medical circumcision for HIV prevention in Sub-Saharan Africa; a mixed methods systematic review, Journal of the International AIDS Society, Vol: 22, Pages: 40-53, ISSN: 1758-2652
IntroductionUNAIDS has recommended that in 14 countries across sub‐Saharan Africa (SSA), 90% of men aged 10 to 29 years should be circumcised by 2021 to help reduce transmission of HIV. To achieve this target demand creation programmes have been widely implemented to increase demand for Voluntary Medical Male Circumcision (VMMC). This review explores the effectiveness of demand creation interventions and factors affecting programme implementation.MethodsWe completed a mixed methods systematic review searching Medline, Embase, Global health, psycINFO and CINAHL databases in August 2018 with no time restrictions. Demand creation interventions conducted in SSA were categorized and quantitative data about VMMC uptake was used to compare relative and absolute effectiveness of interventions. Qualitative data were summarized into themes relevant to the delivery and impact of programmes.Results and discussionEighteen of the 904 titles were included in the review. Effective interventions were identified in each demand creation category: financial incentives, counselling or education, involvement of influencers and novel information delivery. Of the 11 randomized controlled trials (RCTs), the greatest absolute impact on VMMC prevalence was seen with a complex intervention including VMMC promotion training for religious leaders (compared to control: 23% (95% CI 22.8 to 23.8) absolute increase; odds ratio (OR) 3.2 (1.4 to 7.3)). Financial incentives generally produced the largest relative effects with men up to seven‐times more likely to undergo VMMC in the intervention arm compared to control (adjusted OR 7.1 (95% CI 2.4 to 20.8), 7.1% (3.7 to 10.5) absolute increase). Qualitative findings suggest that interventions are more impactful when they are judged appropriate and acceptable by the target population; delivered by people with relevant personal experience; and addressing broader social and cultural influences through partnership with and education of community leaders.Con
Papageorgiou V, Crittendon E, Davies B, et al., 2019, PROSPERO registration: Impact of pre-exposure prophylaxis (PrEP) on the risk of bacterial sexually transmitted infections (STIs) among cisgender women: a systematic review, PROSPERO International prospective register of systematic reviews
Ronn M, Mc Grath-Lone L, Davies B, et al., 2019, Evaluation of the performance of nucleic acid amplification tests (NAATs) in detection of chlamydia and gonorrhoea infection in vaginal specimens relative to patient infection status: a systematic review, BMJ Open, Vol: 9, ISSN: 2044-6055
OBJECTIVE: We aimed to assess the performance of NAATs using vaginal specimens in comparison to other urogenital specimens in their ability to detect chlamydia and gonorrhea infection in women.DESIGN: Systematic review.DATA SOURCES: EMBASE and Ovid MEDLINE databases through 3 October 2017.ELIGIBILITY CRITERIA FOR SELECTING STUDIES: We included studies that tested samples from the vagina and ≥1 other site (cervix and/or urine) with ≥2 NAATs for chlamydia and ≥2 NAATs or 1 NAAT and culture for gonorrhoea for each site.DATA EXTRACTION AND SYNTHESIS: We compared the performance of NAATs on specimens taken from the vagina to those from the cervix or urine in diagnosing chlamydia and gonorrhoea infection in women based on patient infection status (PIS). We analysed the performance using vaginal specimens compared to PIS. Performance is defined as the sensitivity of a NAAT using a specimen site and PIS status of the patient. We assessed risk of bias using modified QUADAS-2.RESULTS: Nine publications met the inclusion criteria (eight for chlamydia; six for gonorrhoea) and were narratively reviewed. Pooled summary estimates were not calculated due to the variable methodology and PIS definitions. Tests performed on vaginal specimens accomplished similar performance to cervical and urine specimens for chlamydia (range of performance estimates: vaginal 65-100%, cervical 59-97%, urine 57-100%) and gonorrhoea (vaginal 64-100%, cervical 85-100%, urine 67-94%). Vaginal specimens were estimated to have a performance >80% for chlamydia and gonorrhoea infections in all but one study.CONCLUSIONS: Performance of the NAATs for chlamydia and gonorrhea detection using vaginal specimens was similar to that of cervical and urine specimens relativeto PIS. As vaginal samples have a higher acceptability and lower cost, the study can support clinical testing guidelines by providing evidence that vaginal samples are a suitable alternative to traditional test sites.
Beardon S, Patel K, Davies B, et al., 2018, Informal Carers' Perspectives on the Delivery of Acute Hospital Care for Patients with Dementia: A Systematic Review, BMC Geriatrics, Vol: 23, ISSN: 1471-2318
Background: Providing high quality acute hospital care for patients with dementia is an increasing challenge asthe prevalence of the disease rises. Informal carers of people with dementia are a critical resource for improvinginpatient care, due to their insights into patients’ needs and preferences. We summarise informal carers’ perspectives ofacute hospital care to inform best practice service delivery.Methods: We conducted a systematic search of bibliographic databases and sought relevant grey literature. We usedthematic synthesis analysis to assimilate results of the studies and describe components of care that influence perceivedquality.Results: Twenty papers met the inclusion criteria. Findings identified four overarching components of care thatinfluenced carer experience and their perceptions of care quality: ‘Patient care’, ‘Staff interactions’, ‘Carer’s situation’ and‘Hospital environment’. Need for improvement was identified in staff training, provision of help with personal careneeds, and dignified treatment of patients. Carers need to be informed, involved and supported during hospitaladmission in order to promote the most positive experience.Conclusion: This review identifies common perspectives of informal carers of people with dementia in the acutehospital setting and highlights important areas to address to improve the experience of an admission for both carerand patient.
Davies B, Turner KME, Frolund M, et al., 2018, Pelvic inflammatory disease risk following negative results from chlamydia nucleic acid amplification tests (NAATs) versus non-NAATs in Denmark: A retrospective cohort study, PLoS Medicine, Vol: 15, ISSN: 1549-1277
BackgroundNucleic Acid Amplification Tests (NAATs) are the recommended test type for diagnosing Chlamydia trachomatis (chlamydia). However, less sensitive diagnostic methods—including direct immunofluorescence (IF) and enzyme-linked immunoassay (ELISA)—remain in use in lower resourced settings. We estimate the risk of pelvic inflammatory disease (PID) following undiagnosed infection in women tested with non-NAATs and estimate the health gain from using accurate diagnostic tests.Methods and findingsWe used Denmark’s national Chlamydia Study dataset to extract all chlamydia tests performed in women aged 15–34 years (1998–2001). Tests were categorised as non-NAAT (IF/ELISA) or NAAT and limited to each woman’s first test in the study period. We linked test data to hospital presentations for PID within 12 months from the Danish National Patient Register. The study included 272,105 women with a chlamydia test, just under half (44.78%, n = 121,857) were tested using NAATs. Overall, 6.38% (n = 17,353) tested positive for chlamydia and 0.64% (n = 1,732) were diagnosed with PID within 12 months. The risk of PID following a positive chlamydia test did not differ by test type (NAAT 0.81% [95% CI 0.61–1.00], non-NAAT 0.78% [0.59–0.96]). The risk of PID following a negative test was significantly lower in women tested with NAATs compared to non-NAATs (0.55% [0.51–0.59] compared to 0.69% [0.64–0.73]; adjusted odds ratio (AOR) 0.83 [0.75–0.93]). We estimate that 18% of chlamydia infections in women tested with a non-NAAT were undiagnosed and that the risk of progression from undiagnosed chlamydia infection to PID within 12 months was 9.52% (9.30–9.68). Using non-NAATs could lead to an excess 120 cases of PID per 100,000 women tested compared to using NAATs. The key limitations of this study are under ascertainment of PID cases, misclassification bias in chlamydia and PID exposure status, bias to the association
Davies B, turner KME, Leung S, et al., 2017, Comparison of the population excess fraction of chlamydia trachomatis infection on pelvic inflammatory disease at 12-months in the presence and absence of chlamydia testing and treatment: systematic review and retrospective cohort analysis, PLOS One, Vol: 12, ISSN: 1932-6203
Background: The impact of Chlamydia trachomatis (chlamydia) control on the incidence of pelvic inflammatory disease (PID) is theoretically limited by the proportion of PID caused by chlamydia. We estimate the population excess fraction (PEF) of treated chlamydia infection on PID at 12-months in settings with widespread chlamydia control (testing and treatment) and compare this to the estimated PEF of untreated chlamydia. Methods: We used two large retrospective population-based cohorts of women of reproductive age from settings with widespread chlamydia control to calculate the PEF of treated chlamydia on PID at 12-months. We undertook a systematic review to identify further studies that reported the risk of PID in women who were tested for chlamydia (infected and uninfected). We used the same method to calculate the PEF in eligible studies then compared all estimates of PEF. Results: The systematic review identified a single study, a randomised controlled trial of chlamydia screening (POPI-RCT). In the presence of testing and treatment <10% of PID at 12-months was attributable to treated (baseline) chlamydia infections (Manitoba: 8.86%(95%CI 7.15-10.75); Denmark: 3.84%(3.26-4.45); screened-arm POPI-RCT: 0.99%(0.00-29.06)). In the absence of active chlamydia treatment 26.44% (11.57-46.32) of PID at 12-months was attributable to untreated (baseline) chlamydia infections (deferred-arm POPI-RCT). The PEFs suggest that eradicating baseline chlamydia infections could prevent 484 cases of PID at 12-months per 100,000 women in the untreated setting and 13-184 cases of PID per 100,000 tested women in the presence of testing and treatment. Conclusion: Testing and treating chlamydia reduced the PEF of chlamydia on PID by 65% compared to the untreated setting. But in the presence of testing and treatment over 90% of PID could not be attributed to a baseline chlamydia infection. More information is needed about the aetiology of PID to develop effective strategies for impro
Chandrasekaran L, Davies B, Eaton J, et al., 2016, Chlamydia diagnosis rate in England in 2012: an ecological study of local authorities, Sexually Transmitted Infections, Vol: 93, Pages: 226-228, ISSN: 1472-3263
Objectives Local authorities (LAs) in England commission chlamydia screening as part of the National Chlamydia Screening Programme. It is recommended that LAs achieve a chlamydia diagnosis rate of ≥2300 cases per 100 000 population aged 15–24. We describe national patterns in attainment of the chlamydia diagnosis rate recommendation and possible implications of using it to measure LA-level performance.Methods We used publicly available data sets from England (2012) to explore the association between LAs attaining the recommended chlamydia diagnosis rate and population size, socioeconomic deprivation, test setting and sex.Results We used data from 1 197 121 recorded chlamydia tests in females and 564 117 in males. The chlamydia diagnosis rate recommendation was achieved by 22% (72/324) of LAs overall (43% female population; 8% male population). LAs in the highest deprivation quintile were more likely to reach the recommendation than those in the least-deprived quintile for both sexes (women: unadjusted prevalence ratio (UPR) 7.43, 95% CI 3.65 to 15.11; men: UPR 7.00, 95% CI 1.66 to 29.58). The proportion of tests performed in genitourinary medicine clinics was negatively associated with attainment of the recommended diagnosis rate (UPR 0.95, 0.93 to 0.97).Conclusions Chlamydia diagnosis rate recommendations that reflect local area deprivation (as a proxy for disease burden) may be more appropriate than a single national target if the aim is to reduce health inequalities nationally. We suggest LAs monitor their chlamydia diagnosis rate, test coverage and test positivity across a range of measures (including setting and sex) and pre/post changes to commissioned services. Critical evaluation of performance against the recommendation should be reflected in local commissioning decisions.
Davies B, Turner K, Frolund M, et al., 2016, Risk of reproductive complications following chlamydia testing: a population-based retrospective cohort study in Denmark, Lancet Infectious Diseases, Vol: 16, Pages: 1057-1064, ISSN: 1473-3099
Background: Uncertainty in the risk of reproductive complications (pelvic inflammatory disease (PID), ectopic pregnancy (EP) and tubal factor infertility (TFI)) following chlamydia infection and repeat infection hampers the design of evidence-based chlamydia control programmes. We estimate the association between diagnosed chlamydia and episodes of hospital healthcare (in-patient, out-patient and emergency department) for a reproductive complication.Methods: We constructed and analysed a retrospective population-based cohort of women aged 15-44 years from administrative records in Denmark (1995-2012). Findings: The 516,720 women (103,344 positive, 182,879 negative, 230,497 never-tested) had a mean follow-up of 7.96 years. Compared to women with only negative tests, the risk of each complication was 30% higher in women with ≥1 positive test (adjusted hazard ratios (AHRs) PID 1·50(1·43-1·57); EP 1·31(1·25-1·38); TFI 1·37(1·24-1·52)) and 60% lower in women who were never-tested (AHRs PID 0·33(0·31-0·35); EP 0·42(0·39-0·44); TFI 0·29(0·25-0·33)). A positive test had a minor absolute impact on health as the difference in the lifetime incidence of complications was small between women who tested positive and those who tested negative (PID 0.6%; EP 0.2%; TFI 0·1%). Repeat infections increased the risk of PID by a further 20% (AHR 1·20(1·11-1·31)). Interpretation: A single diagnosed chlamydia infection increased the risk of all complications and a repeat diagnosed infection further increased the risk of PID. Therefore control programmes must prevent first and repeat infections to improve women’s reproductive health.
Davies B, Ward H, 2016, A pathway to chlamydia control: updated ECDC guidance, Sexually Transmitted Infections, Vol: 92, Pages: 483-484, ISSN: 1472-3263
In 2009, the European Centre for Disease Prevention and Control (ECDC) published guidance on chlamydia (Chlamydia trachomatis) control in Europe.1 In it we recommended that EU/EEA member states ensure the provision of basic resources and systems (for diagnosis, case and partner management) before embarking on any expanded screening programme. This guidance was based on evidence first that there was a huge variation in availability of clinical services for chlamydia across member states, and second that the evidence for population level programmes was missing.1 ,2 This month ECDC has released updated guidance that we developed with the support of ECDC experts following a programme of work to update the evidence, including an extensive review of the epidemiology and natural history of chlamydia and the clinical and cost-effectiveness of screening programmes.3 The team also repeated the survey of member states, and assessed the impact of the original guidance.4 ,5The survey showed that more countries had established essential diagnostic and management facilities and guidelines;6 it was hard to attribute this …
Davies B, Ward H, 2016, Guidance on chlamydia control in Europe 2015, Stockholm, Sweden, Publisher: European Centre for Disease Prevention and Control, TQ-01-16-029-EN-N
Executive summaryThis evidence-based guidance updates the 2009 ECDC Chlamydia control in Europe guidance [5]. It was developed by a technical expert group using evidence gathered by the Chlamydia control in Europe programme of work, which ECDC commissioned in 2011 and presented in three accompanying technical reports in 2014 and 2015. The work included a critical review and update of the scientific evidence on the epidemiology and natural history of chlamydia and the clinical and cost-effectiveness of screening programmes, an update of information aboutchlamydia prevention and control activities in EU/EEA Member States, and a review of the impact of the 2009 ECDC chlamydia control guidance. In 2014, an expert consultation provided in-depth information about the use of the 2009 guidance within countries and made suggestions for the revision of the guidance.The aim of this guidance is to support Member States to develop, implement or improve national or local strategies for chlamydia control. This guidance sets out the current evidence base behind the proposed options, highlights key gaps in knowledge, and suggests effective options for national chlamydia control strategies. It is directedprimarily at policy advisors but should be useful for programme managers and experts in sexual health, especially those at the European or national levels.The evidence-based options presented here should be interpreted and applied according to clinical, epidemiological, healthcare and resource environments: there is marked variation in current chlamydia controlstrategies across EU/EEA Member States which reflects differences in available resources, health priorities and uncertainties in the evidence-base for chlamydia control interventions. The evidence base for primary prevention activities is still deficient but expert opinion is that it is prudent to offer these interventions to all at-risk individuals.Diagnosing and treating cases of chlamydia can improve the health of the affect
Ward H, Davies B, Ronn M, 2015, Chlamydia control in Europe: Qualitative evaluation of the impact of the2009 ECDC guidance document Chlamydia control in Europe, Stockholm, Sweden, Publisher: European Centre for Disease Prevention and Control, TQ-02-15-038-EN-N
In 2011, the European Centre for Disease Prevention and Control (ECDC) commissioned a programme of work to improve knowledge about the impact of chlamydia and chlamydia control in Europe. The aim of this project was to critically review and update the scientific evidence on the epidemiology and natural history of chlamydia and the clinical and cost-effectiveness of screening, update information about chlamydia prevention and control activities in EU/EEA Member States, and review the impact of the 2009 ECDC chlamydia control guidance. This technical report describes the evaluation of the impact of the 2009 guidance document on policymaking in Member States and presents recommendations for a revised version of the guidance. It includes an overview of the responses collected during the 2012 survey on chlamydia control activities in EU/EEA Member States. Different user types – with regard to the guideline document – were identified and described in this report. In addition, a qualitative analysis of the discussions at the March 2014 meeting was conducted. The meeting had brought together experts from Member States who discussed their experiences with the guidance document.This report concludes with evidence-based recommendations for the revision of the 2009 guidance document.
Davies B, 2014, The association between Chlamydia trachomatis and pelvic inflammatory disease: findings from observational studies
Davies B, Ward H, Leung S, et al., 2014, Heterogeneity in Risk of Pelvic Inflammatory Diseases After Chlamydia Infection: A Population-Based Study in Manitoba, Canada, Journal of Infectious Diseases, Vol: 210, Pages: S549-S555, ISSN: 1537-6613
Background. The association between chlamydia infection and pelvic inflammatory disease (PID) is a key parameterfor models evaluating the impact of chlamydia control programs. We quantified this association using aretrospective population-based cohort.Methods. We used administrative health data sets to construct a retrospective population-based cohort ofwomen and girls aged 12–24 years who were resident in Manitoba, Canada, between 1992 and 1996. We performedsurvival analysis on a subcohort of individuals who were tested for chlamydia to estimate the risk of PID diagnosed ina primary care, outpatient, or inpatient setting after ≥1 positive chlamydia test.Results. A total of 73 883 individuals contributed 625 621 person years of follow-up. Those with a diagnosis ofchlamydia had an increased risk of PID over their reproductive lifetime compared with those who tested negative(adjusted hazard ratio [AHR], 1.55; 95% confidence interval [CI], 1.43–1.70). This risk increased with each subsequentinfection: the AHR was 1.17 for first reinfection (95% CI, 1.06–1.30) and 1.35 for the second (95% CI,1.04–1.75). The increased risk of PID from reinfection was highest in younger individuals (AHR, 4.55 (95% CI,3.59–5.78) in individuals aged 12–15 years at the time of their second reinfection, compared with individualsolder than 30 years).Conclusions. There is heterogeneity in the risk of PID after a chlamydia infection. Describing the progression toPID in mathematical models as an average rate may be an oversimplification; more accurate estimates of the costeffectivenessof screening may be obtained by using an individual-based measure of risk. Health inequalities may bereduced by targeting health promotion interventions at sexually active girls younger than 16 years and those with ahistory of chlamydia.
Davies B, Anderson S-J, Turner KME, et al., 2014, How robust are the natural history parameters used in chlamydia transmission dynamic models? A systematic review, THEORETICAL BIOLOGY AND MEDICAL MODELLING, Vol: 11
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Davies B, Turner K, Ward H, 2013, Risk of Pelvic Inflammatory Disease After Chlamydia Infection in a Prospective Cohort of Sex Workers, SEXUALLY TRANSMITTED DISEASES, Vol: 40, Pages: 230-234, ISSN: 0148-5717
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Saikat S, Kreis I, Davies B, et al., 2013, The impact of PFOS on health in the general population: a review, ENVIRONMENTAL SCIENCE-PROCESSES & IMPACTS, Vol: 15, Pages: 329-335, ISSN: 2050-7887
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