Vahé Nafilyan

Vahé Nafilyan
King's College London | KCL · Department of Management

About

114
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Publications

Publications (114)
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Objective Evaluate the impact of bariatric surgery on monthly earnings and employee status among working-age adults, and examine variations across sociodemographic characteristics. Design Retrospective longitudinal cohort study using national, linked administrative datasets. Setting Hospital inpatient services in England between 1 April 2014 and 31...
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People suffering from common mental disorders (CMD) such as depression and anxiety are more likely to be economically inactive. Psychological therapies are highly effective at treating CMDs, but less is known about their impact on long-term labour market outcomes. Using national treatment programme data in England, NHS Talking Therapies (NHSTT), wi...
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Introduction Endometriosis is a chronic disease and the second most common gynaecological condition in the UK, affecting approximately 1.5 million women. It is characterised by the growth of endometrial tissue outside the uterus, causing varying symptoms and having far reaching socioeconomic impacts. We utilise population level hospital admissions...
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Background Higher levels of education are associated with slower cognitive decline and a lower risk of dementia, with some evidence of a causal relationship. However, the mechanisms explaining these associations are not well established. Methods We collected data on dementia knowledge using a cross-sectional household survey representative of the...
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Objective To describe which combinations of long term conditions were associated with a higher risk of hospital admission or death during winter 2021-22 (the third wave of the covid-19 pandemic) in adults in England. Design Population based cohort study. Setting Linked primary and secondary care data from the General Practice Extraction Service D...
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Objective and ApproachThe environment in and around children’s homes and schools can influence their health and educational outcomes. Better understanding of how these potentially modifiable environmental risk factors can affect children is crucial in enabling the creation of healthier and more equitable places. We aim to establish the Kids’ Enviro...
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Child mortality is a common measure of the overall health of society. Maternal characteristics, such as ethnicity and socioeconomic status are known to contribute to inequalities in health and mortality in babies and children. Overall, in the UK babies born to non-white mothers have a higher risk of mortality, and there is also a strong association...
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Objective and ApproachIn England, the National human papillomavirus (HPV) HPV Immunisation Programme was introduced for young girls in 2008. Whilst clinical trials have shown high vaccine effectiveness, real-world evidence is still accruing. Estimating vaccine effectiveness based on real-world data without randomised control trials is challenging,...
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In England, the National human papillomavirus (HPV) immunisation programme was introduced in 2008 to prevent cervical cancer. Girls aged 12 to 13 were offered routine vaccination, and those aged 14 to 18 years in 2008 were offered 'catch-up' vaccination. Using Census 2011, Hospital Episode Statistics and mortality data for the population of England...
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Background Evidence on the long-term employment consequences of SARS-CoV-2 infection is lacking. We used data from a large, community-based sample in the UK to estimate associations between Long Covid and employment outcomes. Methods This was an observational, longitudinal study using a pre–post design. We included survey participants from 3 Febru...
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Background Type 2 diabetes is a leading cause of morbidity and mortality but is often undiagnosed. Non-diabetic hyperglycaemia increases T2D risk, and its prevalence is increasing. Understanding the scale of undiagnosed T2D and NDH and identifying at-risk groups is important for detection and intervention. Methods We used the 2013-2019 Health Surve...
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Background The risk of suicide is complex and often a result of multiple interacting factors. Understanding which groups of the population are most at risk of suicide is important to inform the development of targeted public health interventions. Methods We used a novel linked dataset that combined the 2011 Census with the population-level mortali...
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The emergence of the COVID-19 vaccination has been critical in changing the course of the COVID-19 pandemic. To ensure protection remains high in vulnerable groups booster vaccinations in the UK have been targeted based on age and clinical vulnerabilities. We undertook a national retrospective cohort study using data from the 2021 Census linked to...
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We compare the impact of the first two waves of the COVID-19 pandemic on risk of age-standardized mortality by sex, UK country, and English region. Each wave is defined as lasting 26 weeks and are consecutive beginning in 2020 week 11. The expected rate is estimated from 2015 to 2019 mean and the projected mortality trend from the same period are u...
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Objectives To examine the relationship between deprivation and Accident and Emergency department attendance. Design Retrospective cohort study. Setting England, United Kingdom, from 21 March 2021 to March 2022 Participants All individuals in the 2021 Census, aged 0 to 95 with an Emergency Department attendance record within the Emergency Care Datas...
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Background Little is known about the risk of Long Covid following reinfection with SARS-CoV-2. We estimated the likelihood of new-onset, self-reported Long Covid after a second SARS-CoV-2 infection, and compared to a first infection. Methods We included UK COVID-19 Infection Survey participants who tested positive for SARS-CoV-2 between 1 November...
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Background Hypertension is a leading cause of morbidity and mortality worldwide, yet a substantial proportion of cases are undiagnosed. Understanding the scale of undiagnosed hypertension and identifying groups most at risk is important to inform approaches to detection. Methods In this cross-sectional cohort study, we used data from the 2015 to 2...
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Introduction & Background Evidence is mounting that children’s physical environment (e.g. in and around the home, school, and neighbourhood) is critical for their long-term health and education. Early life exposure to factors such as indoor and outdoor air pollution, or a lack of access to greenspaces are associated with the development of long-ter...
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Objectives With suicide a major public health concern, it is vital research identifies predictors of suicide to support vulnerable groups who should be targeted for intervention. We use a novel linkage of 2011 Census and population level mortality data to assess which risk factors are important predictors of suicide. Methods Exposures of interest w...
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Background The annual winter season poses substantial challenges to the National Health Service (NHS) in England. Hospitalisation and mortality increase during winter, especially in people with multiple long-term conditions (MLTC or multimorbidity). We aimed to describe which combinations of long-term conditions (LTC) are associated with a higher r...
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Objective To estimate vaccine effectiveness for preventing covid-19 related hospital admission in individuals first infected with the SARS-CoV-2 virus during pregnancy compared with those of reproductive age who were not pregnant when first infected with the virus. Design Population based cohort study. Setting Office for National Statistics Publi...
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Background: The emergence of the COVID-19 vaccination has been critical in changing the course of the COVID-19 pandemic, with estimates suggesting vaccinations have prevented millions of deaths worldwide. To ensure protection remains high in groups at high-risk, booster vaccinations in the UK have been targeted based on age and clinical vulnerabili...
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Background Hypertension is a leading cause of morbidity and mortality worldwide, yet a substantial proportion of cases are undiagnosed. Understanding the scale of undiagnosed hypertension and identifying groups most at risk is important to inform approaches to detection. Methods We used data from the 2015 to 2019 Health Survey for England, an annu...
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Objective: To estimate the effectiveness of COVID-19 vaccination against hospitalisation for COVID-19 and death involving COVID-19 in England using linked population level data sources including the 2021 Census. Design: Retrospective cohort study. Setting: England, 21 March 2021 to 20 March 2022. Participants: Individuals alive and aged 16+ on 21 M...
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Background Excess mortality from all causes combined during the COVID-19 pandemic in England and Wales in 2020 was predominantly higher for essential workers. In 2021, the vaccination programme had begun, new SARS-CoV-2 variants were identified and different policy approaches were used. We have updated our previous analyses of excess mortality in E...
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Introduction Older people were at particular risk of morbidity and mortality during COVID-19. Consequently, they experienced formal (externally imposed) and informal (self-imposed) periods of social isolation and quarantine. This is hypothesised to have led to physical deconditioning, new-onset disability and frailty. Disability and frailty are not...
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Introduction At the start of the COVID-19 pandemic there was an urgent need to identify individuals at highest risk of severe outcomes, such as hospitalisation and death following infection. The QCOVID risk prediction algorithms emerged as key tools in facilitating this which were further developed during the second wave of the COVID-19 pandemic to...
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Background: Since 2008, the Improving Access to Psychological Therapies (IAPT) programme has offered adults in England evidence-based psychological treatments for common mental disorders (CMDs) such as depression and anxiety disorders. However, inequalities in access have not been explored at the national level. Methods: Using a unique individua...
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Background: Little is known about the risk of Long Covid following reinfection with SARS-CoV-2. We estimated the likelihood of new-onset, self-reported Long Covid after a second SARS-CoV-2 infection, and compared to a first infection. Methods: We included UK COVID-19 Infection Survey participants who tested positive for SARS-CoV-2 between 1 Novembe...
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Objective To examine sociodemographic inequalities in people with SARS-CoV-2 during the second (alpha) and third (delta) waves of the covid-19 pandemic. Design Retrospective, population based cohort study. Setting Resident population of England. Participants 39 006 194 people aged 10 years and older who were enumerated in the 2011 census, regist...
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Several studies have reported associations between COVID-19 vaccination and risk of cardiac diseases, especially in young people; the impact on mortality, however, remains unclear. We use national, linked electronic health data in England to assess the impact of COVID-19 vaccination and positive SARS-CoV-2 tests on the risk of cardiac and all-cause...
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Background: Evidence on the long-term employment consequences of SARS-CoV-2 infection is lacking. We used data from a large, community-based sample in the UK to estimate associations between Long Covid and subsequent employment outcomes. Methods: This was an observational, longitudinal study using a pre-post design. We included UK COVID-19 Infectio...
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Background: The risk of COVID-19 severity and mortality differs markedly by age, socio-demographic characteristics and pre-existing health status. Various studies have suggested that higher air pollution exposures also increase the likelihood of dying from COVID-19. Objectives: To assess the association between long-term outdoor air pollution (NO2,...
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Background The diagnosis of a severe physical health condition can cause psychological distress and lead to severe depression. The association between severe physical health conditions and the risk of suicide, and how the risk of suicide changes in the months following diagnosis, are not clear. Methods We estimated whether a diagnosis of severe ph...
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There are important differences in the risk of SARS-CoV-2 infection and death depending on occupation. Infections in healthcare workers have received the most attention, and there are clearly increased risks for intensive care unit workers who are caring for COVID-19 patients. However, a number of other occupations may also be at an increased risk,...
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Background Ethnic minority groups in England have been disproportionately affected by the COVID-19 pandemic and have lower vaccination rates than the White British population. We examined whether ethnic differences in COVID-19 mortality in England have continued since the vaccine rollout and to what extent differences in vaccination rates contribut...
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This paper provides novel evidence on how a sharp increase in labor force participation among older women affects the provision of informal care to their older parents. Based on data from Understanding Society – The UK Household Longitudinal Study, we use an instrumental variable approach that exploits a unique reform that increased the female Stat...
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Background: Parental leave policies have been hypothesized to benefit mothers' mental health. We assessed the impact of a 6-week extension of parental leave in Denmark on maternal mental health. Methods: We linked individual-level data from Danish national registries on maternal sociodemographic characteristics and psychiatric diagnoses. A regre...
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Objective: To estimate vaccine effectiveness (VE) for preventing COVID-19 hospital admission in women first infected with SARS-CoV-2 during pregnancy, and assess how this compares to VE among women of reproductive age who were not pregnant when first infected. Design: Population-based cohort study using national, linked Census and administrative da...
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This cohort study of adults in England evaluates the association of sociodemographic and clinical risk factors with death from COVID-19 among individuals who completed primary vaccination and received a messenger RNA (mRNA) booster.
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Background Monitoring differences in COVID-19 vaccination uptake in different groups is crucial to help inform the policy response to the pandemic. A key data gap is the absence of data on uptake by occupation. This study investigates differences in vaccination rates by occupation in England, using nationwide population-level data. Methods We calc...
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Estimating real-world vaccine effectiveness is vital to assess the COVID-19 vaccination programme and to inform the ongoing policy response. However, estimating vaccine effectiveness using observational data is inherently challenging because of the non-randomised design and potential for unmeasured confounding. We used a Regression Discontinuity De...
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Objectives During the COVID-19 pandemic, higher mortality among some ethnic minority groups was identified and has become the subject of significant public and government interest, highlighting an urgent requirement to quantify the reliability of ethnicity classification across health administrative data sets, which are utilised in health analysis...
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OBJECTIVE: To assess the risk of COVID-19 death following infection from Omicron BA.1 relative to Delta (B.1.617.2). DESIGN: Retrospective cohort study. SETTING: England, UK, 1 December 2021 to 30 December 2021. PARTICIPANTS: 1,035,149 people aged 18-100 years who tested positive for SARS-CoV-2 in the national surveillance programme, and had an inf...
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Background Ethnic differences in the risk of severe COVID-19 may be linked to household composition. We quantified the association between household composition and risk of severe COVID-19 by ethnicity for older individuals. Methods With the approval of NHS England, we analysed ethnic differences in the association between household composition an...
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Objective: To assess the risk of covid-19 death after infection with omicron BA.1 compared with delta (B.1.617.2). Design: Retrospective cohort study. Setting: England, United Kingdom, from 1 December 2021 to 30 December 2021. Participants: 1 035 149 people aged 18-100 years who tested positive for SARS-CoV-2 under the national surveillance...
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Background Although most adults infected with SARS-CoV-2 fully recover, a proportion have ongoing symptoms, or post-COVID conditions (PCC), after infection. The objective of this analysis was to estimate the number of US adults with activity-limiting PCC on November 1, 2021. Methods We modeled the prevalence of PCC using reported infections occurr...
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Objective: This study aimed to understand whether the proportionate mortality of COVID-19 for various occupational groups has varied over the pandemic. Methods: We used the Office for National Statistics (ONS) mortality data for England and Wales. The deaths (20-64 years) were classified as either COVID-19-related using ICD-10 codes (U07.1, U07....
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OBJECTIVE: To estimate associations between COVID-19 vaccination and Long Covid symptoms in adults who were infected with SARS-CoV-2 prior to vaccination. DESIGN: Observational cohort study using individual-level interrupted time series analysis. SETTING: Random sample from the community population of the UK. PARTICIPANTS: 28,356 COVID-19 Infection...
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Introduction The QCOVID algorithm is a risk prediction tool for infection and subsequent hospitalisation/death due to SARS-CoV-2. At the time of writing, it is being used in important policy-making decisions by the UK and devolved governments for combatting the COVID-19 pandemic, including deliberations on shielding and vaccine prioritisation. Ther...
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Ethnicity information is often missing from health data, impeding action on inequalities. Recording and using ethnicity data will require training, efforts at standardization, and policy changes, while engaging with patients and the public.
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Objective To estimate associations between covid-19 vaccination and long covid symptoms in adults with SARS-CoV-2 infection before vaccination. Design Observational cohort study. Setting Community dwelling population, UK. Participants 28 356 participants in the Office for National Statistics COVID-19 Infection Survey aged 18-69 years who receive...
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Background: Exposure to SARS-CoV-2, subsequent development of COVID-19 and death from COVID-19 may vary by occupation, and the risks may be higher for those categorised as 'essential workers'. Methods: We estimated excess mortality by occupational group and sex separately for each month in 2020 and for the entire 12 months overall. Results: Mo...
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Background: The UK began an ambitious COVID-19 vaccination programme on 8 December 2020. This study describes variation in vaccination uptake by sociodemographic characteristics between December 2020 and August 2021. Methods: Using population-level administrative records linked to the 2011 Census, we estimated monthly first dose vaccination rate...
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Ethnic differences in the risk of severe COVID-19 may be linked to household composition. We quantified the association between household composition and risk of severe COVID-19 by ethnicity for older individuals. With the approval of NHS England, we analysed ethnic differences in the association between household composition and severe COVID-19 in...
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Background: We aimed to determine whether children and adults with poorly controlled or more severe asthma have greater risk of hospitalisation and/or death from COVID-19. Methods: We used individual-level data from the Office for National Statistics Public Health Data Asset, based on the 2011 census in England, and the General Practice Extracti...
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Objectives: To assess whether there is a change in the incidence of cardiac and all-cause death in young people following COVID-19 vaccination or SARS-CoV-2 infection in unvaccinated individuals. Design: Self-controlled case series. Setting: National, linked electronic health record data in England. Study population: Individuals aged 12-29 who had...
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Objective To examine socio-demographic disparities in SARS-CoV-2 case rates during the second (Alpha) and third (Delta) waves of the COVID-19 pandemic. Design Retrospective, population-based cohort study. Setting Resident population of England. Participants 39,006,194 people aged 10 years and over who were enumerated at the 2011 Census, register...
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Objective To assess the risk of death involving COVID-19 following infection from Omicron (B.1.1.539/BA.1) relative to Delta (B.1.617.2). Design Retrospective cohort study. Setting England, UK, 1 December 2021 to 25 January 2022. Participants 1,035,163 people aged 18-100 years who tested positive for SARS-CoV-2 in the national surveillance progr...
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Background It is unclear whether receiving two COVID-19 vaccinations before SARS-CoV-2 infection reduces the risk of developing Long Covid symptoms. We examined whether the likelihood of symptoms 12 weeks after infection differed by vaccination status. Methods We included COVID-19 Infection Survey participants aged 18-69 years who tested positive...
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Background: it is unclear whether receiving two COVID-19 vaccinations before SARS-CoV-2 infection reduces the risk of developing Long Covid symptoms. We examined whether the likelihood of symptoms 12 weeks after infection differed by vaccination status. Methods: we included COVID-19 Infection Survey participants aged 18-69 years who tested positiv...
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Introduction COVID-19 risk prediction algorithms can be used to identify at-risk individuals from short-term serious adverse COVID-19 outcomes such as hospitalisation and death. It is important to validate these algorithms in different and diverse populations to help guide risk management decisions and target vaccination and treatment programs to t...
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Objectives: To assess whether ethnic differences in COVID-19 mortality in England have continued into the third wave and to what extent differences in vaccination rates contributed to excess COVID-19 mortality after accounting for other risk factors. Design: Cohort study of 28.8 million adults using data from the Office for National Statistics Pub...
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Objective: To assess the association between household size and risk of non-severe or severe COVID-19. Design: A longitudinal observational study. Setting: This study utilised UK Biobank linked to national SARS-CoV-2 laboratory test data. Participants: 401,910 individuals with available data on household size in UK Biobank. Main outcome mea...
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Obesity and ethnicity are known risk factors for COVID-19 outcomes, but their combination has not been extensively examined. We investigate the association between body mass index (BMI) and COVID-19 mortality across different ethnic groups using linked national Census, electronic health records and mortality data for adults in England from the star...
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Background: Despite generally high coronavirus disease 2019 (COVID-19) vaccination rates in the UK, vaccination hesitancy and lower take-up rates have been reported in certain ethnic minority communities. Methods: We used vaccination data from the National Immunisation Management System (NIMS) linked to the 2011 Census and individual health reco...
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Objectives To estimate occupational differences in COVID-19 mortality and test whether these are confounded by factors such as regional differences, ethnicity and education or due to non-workplace factors, such as deprivation or prepandemic health. Methods Using a cohort study of over 14 million people aged 40–64 years living in England, we analys...
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Objective: To estimate associations between COVID-19 vaccination and Long Covid symptoms in adults who were infected with SARS-CoV-2 prior to vaccination. Design: Observational cohort study using individual-level interrupted time series analysis. Setting: Random sample from the community population of the UK. Participants: 28,356 COVID-19 Infection...
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Background: Monitoring differences in COVID-19 vaccination uptake in different groups is crucial to help inform the policy response to the pandemic. A key gap is the absence of data on uptake by occupation. Methods: Using nationwide population-level d