Imperial College London

DrBethanDavies

Faculty of MedicineSchool of Public Health

Clinical Senior Lecturer in Epidemiology
 
 
 
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bethan.davies06

 
 
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Medical SchoolSt Mary's Campus

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Summary

 

Publications

Publication Type
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to

47 results found

Wang W, Gulliver J, Beevers S, Freni Sterrantino A, Davies B, Atkinson RW, Fecht Det al., 2024, Short-term nitrogen dioxide exposure and emergency hospital admissions for asthma in children: a case-crossover analysis in England, Journal of Asthma and Allergy, Vol: 17, Pages: 349-359, ISSN: 1178-6965

Background:There is an increasing body of evidence associating short-term ambient nitrogen dioxide (NO2) exposure with asthma-related hospital admissions in children. However, most studies have relied on temporally resolved exposure information, potentially ignoring the spatial variability of NO2. We aimed to investigate how daily NO2 estimates from a highly resolved spatio-temporal model are associated with the risk of emergency hospital admission for asthma in children in England.Methods:We conducted a time-stratified case-crossover study including 111,766 emergency hospital admissions for asthma in children (aged 0–14 years) between 1st January 2011 and 31st December 2015 in England. Daily NO2 levels were predicted at the patients’ place of residence using spatio-temporal models by combining land use data and chemical transport model estimates. Conditional logistic regression models were used to obtain the odds ratios (OR) and confidence intervals (CI) after adjusting for temperature, relative humidity, bank holidays, and influenza rates. The effect modifications by age, sex, season, area-level income deprivation, and region were explored in stratified analyses.Results:For each 10 µg/m³ increase in NO2 exposure, we observed an 8% increase in asthma-related emergency admissions using a five-day moving NO2 average (mean lag 0–4) (OR 1.08, 95% CI 1.06–1.10). In the stratified analysis, we found larger effect sizes for male (OR 1.10, 95% CI 1.07–1.12) and during the cold season (OR 1.10, 95% CI 1.08–1.12). The effect estimates varied slightly by age group, area-level income deprivation, and region.Significance:Short-term exposure to NO2 was significantly associated with an increased risk of asthma emergency admissions among children in England. Future guidance and policies need to consider reflecting certain proven modifications, such as using season-specific countermeasures for air pollution control, to protect the at-r

Journal article

Fuertes E, Jarvis D, Lam H, Davies B, Fecht D, Candeias J, Schmidt-Weber C, Douiri A, Slovick A, Scala E, Smith T, Shamji M, Buters J, Cecchi L, Till Set al., 2024, Phl p 5 levels more strongly associated than grass pollen counts with allergic respiratory health, Journal of Allergy and Clinical Immunology, Vol: 153, Pages: 844-851, ISSN: 0091-6749

Background:Studies have linked daily pollen counts to respiratory allergic health outcomes but few have considered allergen levels.Objective:This study assessed associations of grass pollen counts and allergen levels (Phl p 5) with 1) respiratory allergic health symptoms in a panel of 93 adults with moderate-severe allergic rhinitis and 2) daily asthma hospital admissions in London, UK.Methods:Daily symptom and medication scores were collected from adult participants in an allergy clinical trial. Daily counts of asthma hospital admissions in the London general population were obtained from Hospital Episode Statistics data. Daily grass pollen counts were measured using a volumetric air sampler, and novel Phl p 5 levels, using a Chemvol high-volume cascade impactor and ELISA analyses (May-August). Associations between the two pollen variables and daily health scores (dichotomized based on within-person 75th percentiles) were assessed using generalized estimating equation logistic models, and with asthma hospital admissions using Poisson regression models.Results:Daily pollen counts and Phl p 5 levels were each positively associated with reporting a high combined symptom and medication health score in separate models. However, in mutually adjusted models including terms for both pollen counts and Phl p 5 levels, associations remained for Phl p 5 levels (odds ratio [95% confidence intervals]: 1.18 [1.12, 1.24]) but were heavily attenuated for pollen counts (1.00 [0.93, 1.07]). Similar trends were not observed for asthma hospital admissions in London.Conclusion:Grass allergen (Phl p 5) levels are more consistently associated with allergic respiratory symptoms than grass pollen counts.

Journal article

Rashid T, Bennett JE, Muller DC, Cross AJ, Pearson-Stuttard J, Asaria P, Daby HI, Fecht D, Davies B, Ezzati Met al., 2024, Mortality from leading cancers in districts of England from 2002 to 2019: a population-based, spatiotemporal study, The Lancet Oncology, Vol: 25, Pages: 86-98, ISSN: 1213-9432

BACKGROUND: Cancers are the leading cause of death in England. We aimed to estimate trends in mortality from leading cancers from 2002 to 2019 for the 314 districts in England. METHODS: We did a high-resolution spatiotemporal analysis of vital registration data from the UK Office for National Statistics using data on all deaths from the ten leading cancers in England from 2002 to 2019. We used a Bayesian hierarchical model to obtain robust estimates of age-specific and cause-specific death rates. We used life table methods to calculate the primary outcome, the unconditional probability of dying between birth and age 80 years by sex, cancer cause of death, local district, and year. We reported Spearman rank correlations between the probability of dying from a cancer and district-level poverty in 2019. FINDINGS: In 2019, the probability of dying from a cancer before age 80 years ranged from 0·10 (95% credible interval [CrI] 0·10-0·11) to 0·17 (0·16-0·18) for women and from 0·12 (0·12-0·13) to 0·22 (0·21-0·23) for men. Variation in the probability of dying was largest for lung cancer among women, being 3·7 times (95% CrI 3·2-4·4) higher in the district with the highest probability than in the district with the lowest probability; and for stomach cancer for men, being 3·2 times (2·6-4·1) higher in the district with the highest probability than in the one with the lowest probability. The variation in the probability of dying was smallest across districts for lymphoma and multiple myeloma (95% CrI 1·2 times [1·1-1·4] higher in the district with the highest probability than the lowest probability for women and 1·2 times [1·0-1·4] for men), and leukaemia (1·1 times [1·0-1·4] for women and 1·2 times [1·0-1·5] for men). The Spearman rank correlation between probability

Journal article

Atchison C, Davies B, Cooper E, Lound A, Whitaker M, Hampshire A, Azor A, Donnelly C, Chadeau M, Cooke G, Ward H, Elliott Pet al., 2023, Long-term impact of COVID-19 among 242,712 adults in England, Nature Communications, Vol: 14, ISSN: 2041-1723

The COVID-19 pandemic is having a lasting impact on health and well-being. We compare current self-reported health, quality of life and symptom profiles for people with ongoing symptoms following COVID-19 to those who have never tested positive for SARS-CoV-2 infection and those who have recovered from COVID-19. Overall, 276,840/800,000 (34·6%) of invited participants took part. Mental health and health-related quality of life were worse among participants with ongoing persistent symptoms post-COVID compared with those who had never had COVID-19 or had recovered. In this study, median duration of COVID-related symptoms (N = 130,251) was 1·3 weeks (inter-quartile range 6 days to 2 weeks), with 7·5% and 5·2% reporting ongoing symptoms ≥12 weeks and ≥52 weeks respectively. Female sex, ≥1 comorbidity and being infected when Wild-type variant was dominant were associated with higher probability of symptoms lasting ≥12 weeks and longer recovery time in those with persistent symptoms. Although COVID-19 is usually of short duration, some adults experience persistent and burdensome illness.

Journal article

Ward H, Atchison C, Whitaker M, Davies B, Ashby D, Darzi A, Chadeau-Hyam M, Riley S, Donnelly CA, Barclay W, Cooke GS, Elliott Pet al., 2023, Design and implementation of a national program to monitor the prevalence of SARS-CoV-2 IgG antibodies in England using self-testing: the REACT-2 study, American Journal of Public Health, Pages: e1-e9, ISSN: 0090-0036

Data System. The UK Department of Health and Social Care funded the REal-time Assessment of Community Transmission-2 (REACT-2) study to estimate community prevalence of SARS-CoV-2 IgG (immunoglobulin G) antibodies in England. Data Collection/Processing. We obtained random cross-sectional samples of adults from the National Health Service (NHS) patient list (near-universal coverage). We sent participants a lateral flow immunoassay (LFIA) self-test, and they reported the result online. Overall, 905 991 tests were performed (28.9% response) over 6 rounds of data collection (June 2020-May 2021). Data Analysis/Dissemination. We produced weighted estimates of LFIA test positivity (validated against neutralizing antibodies), adjusted for test performance, at local, regional, and national levels and by age, sex, and ethnic group and area-level deprivation score. In each round, fieldwork occurred over 2 weeks, with results reported to policymakers the following week. We disseminated results as preprints and peer-reviewed journal publications. Public Health Implications. REACT-2 estimated the scale and variation in antibody prevalence over time. Community self-testing and -reporting produced rapid insights into the changing course of the pandemic and the impact of vaccine rollout, with implications for future surveillance. (Am J Public Health. Published online ahead of print September 21, 2023:e1-e9. https://doi.org/10.2105/AJPH.2023.307381).

Journal article

Konstantinoudis G, Minelli C, Lam HCY, Fuertes E, Ballester J, Davies B, Vicedo-Cabrera AM, Gasparrini A, Blangiardo Met al., 2023, Asthma hospitalisations and heat exposure in England: a case-crossover study during 2002-2019, Thorax, Vol: 78, Pages: 875-881, ISSN: 0040-6376

BACKGROUND: Previous studies have reported an association between warm temperature and asthma hospitalisation. They have reported different sex-related and age-related vulnerabilities; nevertheless, little is known about how this effect has changed over time and how it varies in space. This study aims to evaluate the association between asthma hospitalisation and warm temperature and investigate vulnerabilities by age, sex, time and space. METHODS: We retrieved individual-level data on summer asthma hospitalisation at high temporal (daily) and spatial (postcodes) resolutions during 2002-2019 in England from the NHS Digital. Daily mean temperature at 1 km×1 km resolution was retrieved from the UK Met Office. We focused on lag 0-3 days. We employed a case-crossover study design and fitted Bayesian hierarchical Poisson models accounting for possible confounders (rainfall, relative humidity, wind speed and national holidays). RESULTS: After accounting for confounding, we found an increase of 1.11% (95% credible interval: 0.88% to 1.34%) in the asthma hospitalisation risk for every 1°C increase in the ambient summer temperature. The effect was highest for males aged 16-64 (2.10%, 1.59% to 2.61%) and during the early years of our analysis. We also found evidence of a decreasing linear trend of the effect over time. Populations in Yorkshire and the Humber and East and West Midlands were the most vulnerable. CONCLUSION: This study provides evidence of an association between warm temperature and hospital admission for asthma. The effect has decreased over time with potential explanations including temporal differences in patterns of heat exposure, adaptive mechanisms, asthma management, lifestyle, comorbidities and occupation.

Journal article

Whitaker M, Davies B, Atchison C, Barclay W, Ashby D, Darzi A, Riley S, Cooke G, Donnelly C, Chadeau M, Elliott P, Ward Het al., 2023, SARS-CoV-2 rapid antibody test results and subsequent risk of hospitalisation and death in 361,801 people, Nature Communications, Vol: 14, ISSN: 2041-1723

The value of SARS-CoV-2 lateral flow immunoassay (LFIA) tests for estimating individual disease risk is unclear. The REACT-2 study in England, UK, obtained self-administered SARS-CoV-2 LFIA test results from 361,801 adults in January-May 2021. Here, we link to routine data on subsequent hospitalisation (to September 2021), and death (to December 2021). Among those who had received one or more vaccines, a negative LFIA is associated with increased risk of hospitalisation with COVID-19 (HR: 2.73 [95% confidence interval: 1.15,6.48]), death (all-cause) (HR: 1.59, 95% CI:1.07, 2.37), and death with COVID-19 as underlying cause (20.6 [1.83,232]). For people designated at high risk from COVID-19, who had received one or more vaccines, there is an additional risk of all-cause mortality of 1.9 per 1000 for those testing antibody negative compared to positive. However, the LFIA does not provide substantial predictive information over and above that which is available from detailed sociodemographic and health-related variables. Nonetheless, this simple test provides a marker which could be a valuable addition to understanding population and individual-level risk.

Journal article

Wang W, Dack S, Mudway I, Walder H, Davies B, Kamanyire R, Fecht Det al., 2023, Brownfield land and health: a systematic review of the literature, PLoS One, Vol: 18, Pages: 1-15, ISSN: 1932-6203

BackgroundBrownfield land is vacant or derelict land that was previously used for industrial or commercial purposes. Brownfield land is increasingly being targeted for housing development, however, depending on the previous use and remediation activity, it might pose potential risks to the health of residents on or in the vicinity of redeveloped sites. This systematic review of the literature synthesises the empirical evidence on the associations between brownfield land and health.MethodsWe systematically searched EMBASE, MEDLINE, Global Health, Web of Science, Scopus and GreenFile using a study protocol registered on PROSPERO (CRD42022286826). The search strategy combined the keywords “brownfield” and its interchangeable terms such as “previously developed land”, and any health outcomes such as “respiratory diseases” and “mortality”. Publications identified from the search were screened for eligibility by two authors, and data were extracted from the selected articles. Study quality was assessed based on the Newcastle-Ottawa Scale.ResultsOf the 1,987 records retrieved, 6 studies met the inclusion criteria; 3 ecological studies, 2 cross-sectional studies, and 1 longitudinal study. There was considerable heterogeneity in the exposure metrics and health outcomes assessed. All studies found significant positive associations between brownfield land proximity or density with at least one health relevant outcome, including poorer self-reported general health, increased mortality rates, increased birth defects, increased serum metal levels, and accelerated immune ageing.ConclusionsBrownfield land may negatively affect the health of nearby residents. The epidemiological evidence on health effects associated with brownfield land in local communities, however, remains inconclusive and limited. Further studies are required to build the evidence base to inform future housing policies and urban planning.

Journal article

Chamberlain RC, Fecht D, Davies B, Laverty AAet al., 2023, Health effects of Low Emission and Congestion Charging Zones: a systematic review, The Lancet Public Health, Vol: 8, Pages: e559-e574, ISSN: 2468-2667

Background: Low Emission Zones (LEZ) and Congestion Charging Zones (CCZ) have beenimplemented in several cities globally. We systematically reviewed the evidence on the impacts ofthese air pollution and congestion reduction schemes on a range of physical health outcomes.Methods: We searched MEDLINE, Embase, Web of Science, IDEAS, Greenfile, and TRID databasesthrough 4 January 2023. We included studies that evaluated the effect of the implementation of aLEZ or CCZ on air pollution-related health outcomes, including cardiovascular and respiratorydiseases, birth outcomes, dementia, lung cancer and diabetes, or road traffic injuries (RTI) usinglongitudinal study designs. We excluded studies without empirical health data. Two authorsindependently assessed papers for inclusion. Results were narratively synthesised and visualisedusing harvest plots. Risk of bias was assessed using the Graphic Appraisal Tool for Epidemiologicalstudies for correlation studies. The protocol was registered with PROSPERO (CRD42022311453).Findings: Of 2,279 studies screened, sixteen were included. Eight studies assessed LEZ in London,Milan, Tokyo, and several German cities, seven assessed the London CCZ and one the StockholmCCZ. Several LEZ studies identified positive effects on air pollution-related outcomes, with reductionsin at least some cardiovascular disease subcategories in five out of six studies investigating thisoutcome, although results for other health outcomes were less consistent. Six out of seven studieson the London CCZ reported reductions in total and/or car RTIs, although one reported an increasein cyclist/motorcyclist injuries and one reported an increase in serious/fatal injuries.Interpretation: Studies were limited in number and varied in design, intervention, and outcomes.Current evidence suggests LEZ schemes reduce air pollution related health outcomes, with thestrongest impact on cardiovascular disease. Evidence on CCZ is mainly limited to London butsuggests they reduce o

Journal article

Bennett J, Rashid T, Zolfaghari A, Doyle Y, Suel E, Pearson-Stuttard J, Davies B, Fecht D, Muller ES, Nathvani RS, Sportiche N, Daby H, Johnson E, Li G, Flaxman S, Toledano M, Asaria M, Ezzati Met al., 2023, Changes in life expectancy and house prices in London from 2002 to 2019: Hyper-resolution spatiotemporal analysis of death registration and real estate data, The Lancet Regional Health Europe, Vol: 27, Pages: 1-13, ISSN: 2666-7762

Background:London has outperformed smaller towns and rural areas in terms of life expectancy increase. Our aim was to investigate life expectancy change at very-small-area level, and its relationship with house prices and their change.Methods:We performed a hyper-resolution spatiotemporal analysis from 2002 to 2019 for 4835 London Lower-layer Super Output Areas (LSOAs). We used population and death counts in a Bayesian hierarchical model to estimate age- and sex-specific death rates for each LSOA, converted to life expectancy at birth using life table methods. We used data from the Land Registry via the real estate website Rightmove (www.rightmove.co.uk), with information on property size, type and land tenure in a hierarchical model to estimate house prices at LSOA level. We used linear regressions to summarise how much life expectancy changed in relation to the combination of house prices in 2002 and their change from 2002 to 2019. We calculated the correlation between change in price and change in sociodemographic characteristics of the resident population of LSOAs and population turnover.Findings:In 134 (2.8%) of London's LSOAs for women and 32 (0.7%) for men, life expectancy may have declined from 2002 to 2019, with a posterior probability of a decline >80% in 41 (0.8%, women) and 14 (0.3%, men) LSOAs. The life expectancy increase in other LSOAs ranged from <2 years in 537 (11.1%) LSOAs for women and 214 (4.4%) for men to >10 years in 220 (4.6%) for women and 211 (4.4%) for men. The 2.5th-97.5th-percentile life expectancy difference across LSOAs increased from 11.1 (10.7–11.5) years in 2002 to 19.1 (18.4–19.7) years for women in 2019, and from 11.6 (11.3–12.0) years to 17.2 (16.7–17.8) years for men. In the 20% (men) and 30% (women) of LSOAs where house prices had been lowest in 2002, mainly in east and outer west London, life expectancy increased only in proportion to the rise in house prices. In contrast, in the 30% (men) and

Journal article

Jefferson E, Cole C, Mumtaz S, Cox S, Giles TC, Adejumo S, Urwin E, Lea D, Macdonald C, Best J, Masood E, Milligan G, Johnston J, Horban S, Birced I, Hall C, Jackson AS, Collins C, Rising S, Dodsley C, Hampton J, Hadfield A, Santos R, Tarr S, Panagi V, Lavagna J, Jackson T, Chuter A, Beggs J, Martinez-Queipo M, Ward H, von Ziegenweidt J, Burns F, Martin J, Sebire N, Morris C, Bradley D, Baxter R, Ahonen-Bishopp A, Smith P, Shoemark A, Valdes AM, Ollivere B, Manisty C, Eyre D, Gallant S, Joy G, McAuley A, Connell D, Northstone K, Jeffery K, Di Angelantonio E, McMahon A, Walker M, Semple MG, Sims JM, Lawrence E, Davies B, Baillie JK, Tang M, Leeming G, Power L, Breeze T, Murray D, Orton C, Pierce I, Hall I, Ladhani S, Gillson N, Whitaker M, Shallcross L, Seymour D, Varma S, Reilly G, Morris A, Hopkins S, Sheikh A, Quinlan Pet al., 2022, A hybrid architecture (CO-CONNECT) to facilitate rapid discovery and access to data across the United Kingdom in response to the COVID-19 pandemic: development study, Journal of Medical Internet Research, Vol: 24, ISSN: 1438-8871

Background:COVID-19 data have been generated across the United Kingdom as a by-product of clinical care and public health provision, as well as numerous bespoke and repurposed research endeavors. Analysis of these data has underpinned the United Kingdom’s response to the pandemic, and informed public health policies and clinical guidelines. However, these data are held by different organizations, and this fragmented landscape has presented challenges for public health agencies and researchers as they struggle to find relevant data to access and interrogate the data they need to inform the pandemic response at pace.Objective:We aimed to transform UK COVID-19 diagnostic data sets to be findable, accessible, interoperable, and reusable (FAIR).Methods:A federated infrastructure model (COVID - Curated and Open Analysis and Research Platform [CO-CONNECT]) was rapidly built to enable the automated and reproducible mapping of health data partners’ pseudonymized data to the Observational Medical Outcomes Partnership Common Data Model without the need for any data to leave the data controllers’ secure environments, and to support federated cohort discovery queries and meta-analysis.Results:A total of 56 data sets from 19 organizations are being connected to the federated network. The data include research cohorts and COVID-19 data collected through routine health care provision linked to longitudinal health care records and demographics. The infrastructure is live, supporting aggregate-level querying of data across the United Kingdom.Conclusions:CO-CONNECT was developed by a multidisciplinary team. It enables rapid COVID-19 data discovery and instantaneous meta-analysis across data sources, and it is researching streamlined data extraction for use in a Trusted Research Environment for research and public health analysis. CO-CONNECT has the potential to make UK health data more interconnected and better able to answer national-level research questions while m

Journal article

Chamberlain RC, Fecht D, Davies B, Laverty AAet al., 2022, Effects of low emission zones and congestion charging zones on physical health outcomes: a systematic review., Lancet, Vol: 400 Suppl 1

BACKGROUND: Road traffic impacts human health through air pollution and road safety issues. Low emission zones (LEZs) and congestion charging zones (CCZs) have therefore been implemented in several cities globally. We systematically reviewed the evidence on the effects of these pollution or congestion reduction schemes on specific physical health outcomes associated with air pollution or traffic exposure. METHODS: We searched MEDLINE, Embase, Web of Science, IDEAS, Greenfile, and TRID databases from database inception to Feb 22, 2022, using search terms such as "low emission/congestion charge/zone" and "cardiovascular/respiratory/injury". Searches were limited to English-language records. We included studies that evaluated the effect of a LEZ or CCZ on air pollution-related outcomes (ie, cardiovascular disease, respiratory disease, birth outcomes, dementia, lung cancer, diabetes) or road traffic injuries, using longitudinal study designs. We excluded studies without empirical health data. Two authors independently assessed papers for inclusion. Results were narratively synthesised and summarised using harvest plots. Risk of bias was assessed using the Graphic Appraisal Tool for Epidemiological studies for correlation studies. This systematic review was registered with PROSPERO, number CRD42022311453. FINDINGS: Of 2068 post-deduplication records screened, fifteen studies were included, with two further studies included from references of eligible studies. Nine (53%) of 17 studies assessed LEZs in London, Milan, Tokyo, and several German cities, seven (41%) assessed the London CCZ, and one (6%) assessed the Stockholm CCZ. Each predefined health outcome was considered by at least one study. Six (75%) of eight LEZ studies considering pollution-related outcomes identified reductions in at least one outcome, with all five on cardiovascular disease identifying reductions for at least one disease subcategory. Of seven London CCZ studies, six (86%) report

Journal article

Chamberlain RC, Fecht D, Davies B, Laverty AAet al., 2022, Effects of low emission zones and congestion charging zones on physical health outcomes: a systematic review.

BACKGROUND: Road traffic impacts human health through air pollution and road safety issues. Low emission zones (LEZs) and congestion charging zones (CCZs) have therefore been implemented in several cities globally. We systematically reviewed the evidence on the effects of these pollution or congestion reduction schemes on specific physical health outcomes associated with air pollution or traffic exposure. METHODS: We searched MEDLINE, Embase, Web of Science, IDEAS, Greenfile, and TRID databases from database inception to Feb 22, 2022, using search terms such as "low emission/congestion charge/zone" and "cardiovascular/respiratory/injury". Searches were limited to English-language records. We included studies that evaluated the effect of a LEZ or CCZ on air pollution-related outcomes (ie, cardiovascular disease, respiratory disease, birth outcomes, dementia, lung cancer, diabetes) or road traffic injuries, using longitudinal study designs. We excluded studies without empirical health data. Two authors independently assessed papers for inclusion. Results were narratively synthesised and summarised using harvest plots. Risk of bias was assessed using the Graphic Appraisal Tool for Epidemiological studies for correlation studies. This systematic review was registered with PROSPERO, number CRD42022311453. FINDINGS: Of 2068 post-deduplication records screened, fifteen studies were included, with two further studies included from references of eligible studies. Nine (53%) of 17 studies assessed LEZs in London, Milan, Tokyo, and several German cities, seven (41%) assessed the London CCZ, and one (6%) assessed the Stockholm CCZ. Each predefined health outcome was considered by at least one study. Six (75%) of eight LEZ studies considering pollution-related outcomes identified reductions in at least one outcome, with all five on cardiovascular disease identifying reductions for at least one disease subcategory. Of seven London CCZ studies, six (86%) report

Poster

Papageorgiou V, Crittendon E, Coukan F, Davies B, Ward Het al., 2022, Impact of daily, oral pre-exposure prophylaxis on the risk of bacterial sexually transmitted infections among cisgender women: a systematic review and narrative synthesis [version 2; peer review: 2 approved], Wellcome Open Research, Vol: 7, Pages: 1-21, ISSN: 2398-502X

Background: There are concerns that the use of pre-exposure prophylaxis (PrEP) may result in an increased incidence of sexually transmitted infections (STIs). Evidence for this is mixed and has mostly been based on reviews focussed on gay and bisexual men and transgender women, while none have summarised evidence in cisgender women.Methods: We conducted a systematic review to explore whether daily, oral PrEP use is associated with changes in bacterial STI occurrence (diagnoses or self-reported) and/or risk among HIV seronegative cisgender women (ciswomen). The quality of evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) tool.Results: We included 11 full text articles in a narrative synthesis, with the studies published between 2012 and 2021. The studies were mostly based in Africa (n=7, 63.6%) and reported on 3168 ciswomen using PrEP aged 16–56 years. Studies had marked differences in variables, including measurements and definitions (e.g., STI type) and limited data available looking specifically at ciswomen, principally in studies with both male and female participants. The limited evidence suggests that PrEP use is not associated with increased STI rates in ciswomen generally; however, adolescent girls and young women in Sub Saharan Africa have a higher prevalence of bacterial STIs prior to PrEP initiation, compared to adult ciswomen and female sex workers.Conclusions: We suggest future PrEP research make efforts to include ciswomen as study participants and report stratified results by gender identity to provide adequate data to inform guidelines for PrEP implementation.PROSPERO registration: CRD42019130438

Journal article

Papageorgiou V, Davies B, Cooper E, Singer A, Ward Het al., 2022, Influence of material deprivation on clinical outcomes among people living with HIV in high-income countries: a systematic review and meta-analysis, AIDS and Behavior, Vol: 26, Pages: 2026-2054, ISSN: 1090-7165

Despite developments in HIV treatment and care, disparities persist with some not fully benefiting from improvements in the HIV care continuum. We conducted a systematic review to explore associations between social determinants and HIV treatment outcomes (viral suppression and treatment adherence) in high-income countries. A random effects meta-analysis was performed where there were consistent measurements of exposures. We identified 83 observational studies eligible for inclusion. Social determinants linked to material deprivation were identified as education, employment, food security, housing, income, poverty/deprivation, socioeconomic status/position, and social class; however, their measurement and definition varied across studies. Our review suggests a social gradient of health persists in the HIV care continuum; people living with HIV who reported material deprivation were less likely to be virologically suppressed or adherent to antiretrovirals. Future research should use an ecosocial approach to explore these interactions across the lifecourse to help propose a causal pathway.

Journal article

Chamberlain R, Fecht D, Davies B, Laverty Aet al., 2022, PROSPERO registration: Impacts of Low Emission and Congestion Charging Zones on physical health outcomes: a systematic review.

Other

Georgiou Delisle T, D'Souza N, Davies B, Benton S, Chen M, Ward H, Abulafi M, NICE FIT Steering Committeeet al., 2022, Faecal immunochemical test for suspected colorectal cancer symptoms: patient survey of usability and acceptability., BJGP Open, Vol: 6

BACKGROUND: Recent evidence suggests that the faecal immunochemical test (FIT) can rule out colorectal cancer (CRC) in symptomatic patients. To date, there is no research on usability and perception of FIT for these patients. AIM: To measure variation in attitudes and perception of FIT in patients with suspected CRC symptoms. DESIGN & SETTING: A cross-sectional survey of a subset of participants of the NICE FIT study. METHOD: A questionnaire was co-developed with patients covering four themes on a Likert scale: FIT feasibility, faecal aversion, patient knowledge, and future intentions. Questionnaire and FIT kits were sent to patients with suspected CRC symptoms participating in the NICE FIT study. Logistic regression explored differences in patients' test perception by ethnic group, language, age, location, deprivation, FIT use, and previous experience. RESULTS: A total of 1151 questionnaires were analysed; 90.2% (95% confidence interval [CI] = 88.3% to 91.8%) of patients found faecal collection straightforward, 76.3% (95% CI = 73.7% to 78.6%) disagreed FIT was unhygienic, and 78.1% (95% CI = 75.6% to 80.4%) preferred FIT to colonoscopy. Preference for FIT over colonoscopy was weaker in patients aged 40-64 years than those >65 years (odds ratio [OR] 0.60; 95% CI = 0.43 to 0.84). Intention to use FIT again was stronger in patients who successfully used FIT than those unsuccessful (OR 11.08; 95% CI = 2.74 to 44.75), and white compared with non-white patients assessed (OR 3.20; 95% CI = 1.32 to 7.75). CONCLUSION: While most patients found FIT practical and hygienic, perception differences were found. Strategies to engage patients with more negative FIT perception should underpin symptomatic FIT pathways.

Journal article

Wilson J, Wallace H, Loftus-Keeling M, Ward H, Davies B, Vargas-Palacios A, Hulme C, Wilcox Met al., 2021, Swab-yourself trial with economic monitoring and testing for infections collectively (SYSTEMATIC): Part 1. A diagnostic accuracy, and cost-effectiveness, study comparing clinician-taken versus self-taken rectal and pharyngeal samples for the diagnosis of gonorrhoea and chlamydia, Clinical Infectious Diseases, Vol: 73, Pages: e3172-e3180, ISSN: 1058-4838

BackgroundUrogenital testing misses extragenital Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT). Extragenital self-sampling is frequently undertaken despite no robust RCT evidence of efficacy. We compared clinician-taken rectal and pharyngeal samples with self-taken samples for diagnostic accuracy and cost in MSM and females.MethodsProspective, convenience, sample in UK sexual health clinic. Randomised order of clinician and self-samples from pharynx and rectum, plus first catch urine (MSM) and vulvovaginal swabs (females), for NG/CT detection.ResultsOf 1793 participants (1284 females, 509 MSM), 116 had NG detected (75 urogenital site, 83 rectum, 72 pharynx); 9.4% infected females and 67.3% MSM were urogenital negative. 276 had CT detected (217 urogenital site, 249 rectum, 63 pharynx); 13.1% infected females and 71.8% MSM were urogenital negative. Sexual history did not identify those with rectal infections. Clinician-rectal and self-rectal positive percent agreements (PPA) for NG detection were 92.8% and 97.6%; clinician-rectal, and self-rectal PPA for CT detection were 95.6% and 97.2%. There was no difference in diagnostic accuracy between clinician and self-taken samples.Clinicians performed swabs quicker than participants so costs were lower. However, in asymptomatic people, non-qualified clinicians would oversee self-swabbing and these costs would be lower than clinician’s.ConclusionsThere was no difference in diagnostic accuracy of clinician compared with self-taken extragenital samples. Sexual history did not identify those with rectal infections so individuals should have extragenital clinician, or self-taken, samples. Clinician swabs cost less than self-swabs but in asymptomatic people, or doing home testing, their costs would be lower than clinician swabs.

Journal article

Delisle TG, D'Souza N, Davies B, Benton S, Chen M, Ward H, Abulafi Met al., 2021, PATIENT PERCEPTION OF FIT IN THE DIAGNOSTIC PATHWAY FOR COLORECTAL CANCER: A MIXED METHOD STUDY, Publisher: BMJ PUBLISHING GROUP, Pages: A166-A166, ISSN: 0017-5749

Conference paper

Rashid T, Bennett J, Paciorek C, Doyle Y, Pearson-Stuttard J, Flaxman S, Fecht D, Toledano M, Li G, Daby H, Johnson E, Davies B, Ezzati Met al., 2021, Life expectancy and risk of death in 6,791 English communities from 2002 to 2019: high-resolution spatiotemporal analysis of civil registration data, The Lancet Public Health, Vol: 6, Pages: e805-e816, ISSN: 2468-2667

Background: There is limited data with high spatial granularity on how mortality and longevity have changed in English communities. We estimated trends from 2002 to 2019 in life expectancy and probabilities of death at different ages for all 6,791 English middle-layer super output areas (MSOAs).Methods: We used de-identified data for all deaths in England from 2002 to 2019 with information on age, sex and MSOA of residence, and population counts by age, sex and MSOA. We used a Bayesian hierarchical model to obtain estimates of age-specific death rates by sharing information across age groups, MSOAs and years. We used life table methods to calculate life expectancy at birth and probabilities of death in different ages by sex and MSOA.Results: In 2002-2006 and 2006-2010, the vast majority of MSOAs experienced a life expectancy increase for both sexes. In 2010-2014, female life expectancy decreased in 351 (5%) of MSOAs. By 2014-2019, the number of MSOAs with declining life expectancy was 1,270 (19%) for women and 784 (12%) for men. The life expectancy increase from 2002 to 2019 was smaller where life expectancy had been lower in 2002, mostly northern urban MSOAs, and larger where life expectancy had been higher in 2002, mostly MSOAs in and around London. As a result of these trends, the gap between the 1st and 99th percentiles of MSOA life expectancy for women increased from 10.7 (95% credible interval 10.4-10.9) in 2002 to reach 14.2 (13.9-14.5) years in 2019, and from 11.5 (11.3-11.7) years to 13.6 (13.4-13.9) years for men. Interpretation: In many English communities, life expectancy declined in the years prior to the Covid-19 pandemic. To ensure that this trend does not continue there is a need for pro-equity economic and social policies, and greater investment on public health and healthcare.

Journal article

Davies B, Araghi M, Moshe M, Gao H, Bennet K, Jenkins J, Atchison C, Darzi A, Ashby D, Riley S, Barclay W, Elliott P, Ward H, Cooke Get al., 2021, Acceptability, usability and performance of lateral flow immunoassay tests for SARS-CoV-2 antibodies: REACT-2 study of self-testing in non-healthcare key workers, Open Forum Infectious Diseases, Vol: 8, ISSN: 2328-8957

Background Seroprevalence studies are essential to understand the epidemiology of SARS-CoV-2. Various technologies, including laboratory assays and point-of-care self-tests, are available for antibody testing. The interpretation of seroprevalence studies requires comparative data on the performance of antibody tests. Methods In June 2020, current and former members of the UK Police forces and Fire service performed a self-test lateral flow immunoassay (LFIA), had a nurse-performed LFIA and provided a venous blood sample for ELISA . We present the prevalence of antibodies to SARS-CoV-2; the acceptability and usability of self-test LFIAs; and determine the sensitivity and specificity of LFIAs compared to laboratory ELISA. Results In this cohort of 5189 current and former members of the Police service and 263 members of the Fire service, 7.4% (396/5,348; 95% CI, 6.7-8.1) were antibody positive. Seroprevalence was 8.9% (6.9-11.4) in those under 40 years, 11.5% (8.8-15.0) in those of non-white ethnicity and 7.8% (7.1-8.7) in those currently working. Self-test LFIA had an acceptability of 97.7% and a usability of 90.0%. There was substantial agreement between within-participant LFIA results (kappa 0.80; 0.77-0.83). The LFIAs had a similar performance: compared to ELISA, sensitivity was 82.1% (77.7-86.0) self-test and 76.4% (71.9-80.5) nurse-performed with specificity of 97.8% (97.3-98.2) and 98.5% (98.1-98.8) respectively. Conclusion A greater proportion of this non-healthcare key worker cohort showed evidence of previous infection with SARS-CoV-2 than the general population at 6.0% (5.8-6.1) following the first wave in England. The high acceptability and usability reported by participants and similar performance of self-test and nurse-performed LFIAs indicate that the self-test LFIA is fit for purpose for home-testing in occupational and community prevalence studies.

Journal article

Davies B, Parkes B, Bennett J, Fecht D, Blangiardo M, Ezzati M, Elliott Pet al., 2021, Community factors and excess mortality in first wave of the COVID-19 pandemic in England, Nature Communications, ISSN: 2041-1723

Risk factors for increased risk of death from Coronavirus Disease 19 (COVID-19) have been identified but less is known on characteristics that make communities resilient or vulnerable to the mortality impacts of the pandemic. We applied a two-stage Bayesian spatial model to quantify inequalities in excess mortality at the community level during the first wave of the pandemic in England. We used geocoded data on all deaths in people aged 40 years and older during March-May 2020 compared with 2015-2019 in 6,791 local communities. Here we show that communities with an increased risk of excess mortality had a high density of care homes, and/or high proportion of residents on income support, living in overcrowded homes and/or high percent of people with a non-White ethnicity (including Black, Asian and other minority ethnic groups). Conversely, after accounting for other community characteristics, we found no association between population density or air pollution and excess mortality. Overall, the social and environmental variables accounted for around 15% of the variation in mortality at community level. Effective and timely public health and healthcare measures that target the communities at greatest risk are urgently needed if England and other industrialised countries are to avoid further widening of inequalities in mortality patterns as the pandemic progresses.

Journal article

Konstantinoudis G, Padellini T, Bennett J, Davies B, Ezzati M, Blangiardo Met al., 2021, Response to "re: long-term exposure to air-pollution and COVID-19 mortality in England: a hierarchical spatial analysis", Environment International, Vol: 150, ISSN: 0160-4120

Journal article

Konstantinoudis G, Padellini T, Bennett J, Davies B, Blangiardo Met al., 2021, Long-term exposure to air-pollution and COVID-19 mortality in England: a hierarchical spatial analysis, Environment International, Vol: 146, ISSN: 0160-4120

Recent studies suggested a link between long-term exposure to air-pollution and COVID-19 mortality. However, due to their ecological design based on large spatial units, they neglect the strong localised air-pollution patterns, and potentially lead to inadequate confounding adjustment. We investigated the effect of long-term exposure to NO2 and PM2.5 on COVID-19 mortality in England using high geographical resolution. In this nationwide cross-sectional study in England, we included 38,573 COVID-19 deaths up to June 30, 2020 at the Lower Layer Super Output Area level (n = 32,844 small areas). We retrieved averaged NO2 and PM2.5 concentration during 2014–2018 from the Pollution Climate Mapping. We used Bayesian hierarchical models to quantify the effect of air-pollution while adjusting for a series of confounding and spatial autocorrelation. We find a 0.5% (95% credible interval: −0.2%, 1.2%) and 1.4% (95% CrI: −2.1%, 5.1%) increase in COVID-19 mortality risk for every 1 μg/m3 increase in NO2 and PM2.5 respectively, after adjusting for confounding and spatial autocorrelation. This corresponds to a posterior probability of a positive effect equal to 0.93 and 0.78 respectively. The spatial relative risk at LSOA level revealed strong patterns, similar for the different pollutants. This potentially captures the spread of the disease during the first wave of the epidemic. Our study provides some evidence of an effect of long-term NO2 exposure on COVID-19 mortality, while the effect of PM2.5 remains more uncertain.

Journal article

Matthews NR, Davies B, Ward H, 2020, Global health education in UK medical schools: a review of undergraduate university curricula, BMJ Global Health, Vol: 5, Pages: 1-12, ISSN: 2059-7908

IntroductionIn recognition of our increasingly globalised world, global health is now arequired component of the medical school curriculum in the UK. We reviewthe current provision of global health education (GHE) in UK medical schoolsto identify gaps in compulsory teaching.MethodsWe conducted a review of the literature to inform a two-part electronic surveyof global health compulsory teaching, optional teaching and pre-electivetraining. Surveys were sent to all 33 UK medical schools for completion by thefaculty lead on global health and the nominated final year studentrepresentative.ResultsSurveys were returned by 29 (88%) medical school faculty and 15 (45%)medical student representatives; 24 (83%) faculty and 10 (67%) studentsreported including GHE in the core curriculum, however, there was widevariation in learning outcomes covered. On average 75% of faculty and 82%of students reported covering recommended global health themes ‘Globalburden of disease’, ‘Socioeconomic and environmental determinants ofhealth’, Human rights and ethics’, and ‘Cultural diversity and health’, whilstonly 48% of faculty and 33% of students reported teaching on ‘Healthsystems’ and ‘Global health governance’. Almost all institutions offeredoptional global health programmes and most offered some form of preelective training, although content and delivery were variable.ConclusionOver the last decade, the inclusion of global health in the core curriculum ofUK medical schools has increased dramatically. Yet, despite interest amongststudents, significant gaps are apparent in current GHE. Governing bodies inmedical education should establish a comprehensive national strategy to helpimprove access to fundamental GHE for all medical students.

Journal article

Delisle TG, D'Souza N, Davies B, Ward H, Abulafi Met al., 2020, Patient acceptability of a home colorectal cancer rule out test, International Surgical Congress of the Association-of-Surgeons-of-Great-Britain-and-Ireland (ASGBI), Publisher: WILEY, Pages: 55-55, ISSN: 0007-1323

Conference paper

Wilson JD, Wallace HE, Loftus-Keeling M, Ward H, Davies B, Vargas-Palacios A, Hulme C, Wilcox MHet al., 2020, Swab-yourself trial with economic monitoring and testing for infections collectively (SYSTEMATIC): Part 2. A diagnostic accuracy, and cost-effectiveness, study comparing rectal, pharyngeal and urogenital samples analysed individually, versus as a pooled specimen, for the diagnosis of gonorrhoea and chlamydia., Clin Infect Dis

BACKGROUND: Sexual history does not accurately identify those with extragenital Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT) so universal extragenital sampling is recommended. Nucleic acid amplification tests (NAATs) are expensive. If urogenital, plus rectal and pharyngeal, samples are analysed the diagnostic cost is trebled. Pooling samples into one NAAT container would cost the same as urogenital samples alone. We compared clinician triple samples analysed individually with self-taken pooled samples for diagnostic accuracy, and cost, in MSM and females. METHODS: Prospective, convenience, sample in UK sexual health clinic. Randomised order of clinician and self-samples from pharynx, rectum, plus first catch urine (FCU) in MSM and vulvovaginal swabs (VVS) in females, for NG and CT detection. RESULTS: Of 1793 participants (1284 females, 509 MSM), 116 had NG detected (75 urogenital, 83 rectum, 72 pharynx). 276 had CT detected (217 urogenital, 249 rectum, 63 pharynx).There was no difference in sensitivities between clinician triple samples and self-pooled specimens for NG (99.1%, 98.3%) but clinician samples analysed individually identified 3% more chlamydia infections than pooled (99.3%, 96.0%; p=0.027). However, pooled specimens identified more infections than VVS/FCU alone. Pooled specimens missed 2 NG and 11 CT infections, whereas VVS/FCU missed 41 NG and 58 CT infections. Self-taken pooled specimens were the most cost-effective. CONCLUSIONS: Just FCU/VVS testing missed many infections. Self-taken pooled samples were as sensitive as clinician triple samples for identifying NG, but clinician samples analysed individually identified 3% more CT infections than pooled. The extragenital sampling was achievable at no additional diagnostic cost to the FCU/VVS. TRIAL REGISTRATION: ClinicalTrials.gov NCT02371109.

Journal article

Bruton J, Jones K, Jenkins R, Davies B, Ward H, Toledano Met al., 2020, Enabling participation of Black and Minority Ethnic (BME) and seldom-heard communities in health research: A case study from the SCAMP adolescent cohort study, Research for All, Vol: 4, Pages: 207-219, ISSN: 2399-8121

Aim: To investigate barriers and facilitators to BME parental consent for children’s involvement in data-sharing aspects of study on mobile phone and wireless device use (SCAMP). To co-produce solutions to increase participation. Methods: Focus groups, telephone interviews, community event, PPI Café; symposium with public, participants and researchers. Results: Barriers were concerns about the research, practical constraints, poor communication. Facilitators were value of research, benefits to others. Solutions to increase participation were community support and clear, simple communication. Overall, trust in the research and the researchers was a key focus of enabling participation.Sharing recommendations: Symposium generated ideas about improving participation including tailoring participant information, engaging with local advocates, involving people in research design and delivery.Key words: Seldom heard, BME, research participation, co-production, PPI, parental consent

Journal article

Papageorgiou V, Singer A, Cooper E, Davies B, Ward Het al., 2020, PROSPERO Registration: A systematic review of social determinants and HIV treatment outcomes among people living with HIV in high-income countries, PROSPERO International prospective register of systematic reviews

Other

Luna Puerta L, Kendall W, Davies B, Day S, Ward Het al., 2020, The reported impact of public involvement in biobanks: a scoping review, Health Expectations, Vol: 23, ISSN: 1369-6513

BackgroundBiobanks increasingly employ public involvement and engagement strategies, though few studies have explored their impact. This review aims to (a) investigate how the impact of public involvement in biobanks is reported and conceptualized by study authors; in order to (b) suggest how the research community might re‐conceptualize the impact of public involvement in biobanks.MethodsA systematic literature search of three electronic databases and the INVOLVE Evidence Library in January 2019. Studies commenting on the impact of public involvement in a biobank were included, and a narrative review was conducted.Results and discussionForty‐one studies covering thirty‐one biobanks were included, with varying degrees of public involvement. Impact was categorized according to where it was seen: ‘the biobank’, ‘people involved’ and ‘the wider research community’. Most studies reported involvement in a ‘functional’ way, in relation to improved rates of participation in the biobank. Broader forms of impact were reported but were vaguely defined and measured. This review highlights a lack of clarity of purpose and varied researcher conceptualizations of involvement. We pose three areas for further research and consideration by biobank researchers and public involvement practitioners.ConclusionsFunctional approaches to public involvement in biobanking limit impact. This conceptualization of involvement emerges from an entrenched technical understanding that ignores its political nature, complicated by long‐standing disagreement about the values of public involvement. This study urges a re‐imagination of impact, re‐conceptualized as a two‐way learning process. More support will help researchers and members of the public to undergo such reflective exercises.

Journal article

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