Background:Electronic health records (EHRs) have the potential to be used to produce detailed disease burden estimates. In this study we created disease estimates using national EHR for three high burden conditions, compared estimates between linked and unlinked datasets and produced stratified estimates by age, sex, ethnicity, socio-economic deprivation and geographical region. Methods:EHRs containing primary care (Clinical Practice Research Datalink), secondary care (Hospital Episode Statistics) and mortality records (Office for National Statistics) were used. We used existing disease phenotyping algorithms to identify cases of cancer (breast, lung, colorectal and prostate), type 1 and 2 diabetes, and lower back pain. We calculated age-standardised incidence of first cancer, point prevalence for diabetes, and primary care consultation prevalence for low back pain. Results:7.2 million people contributing 45.3 million person-years of active follow-up between 2000-2014 were included. CPRD-HES combined and CPRD-HES-ONS combined lung and bowel cancer incidence estimates by sex were similar to cancer registry estimates. Linked CPRD-HES estimates for combined Type 1 and Type 2 diabetes were consistently higher than those of CPRD alone, with the difference steadily increasing over time from 0.26% (2.99% for CPRD-HES vs. 2.73 for CPRD) in 2002 to 0.58% (6.17% vs. 5.59) in 2013. Low back pain prevalence was highest in the most deprived quintile and when compared to the least deprived quintile the difference in prevalence increased over time between 2000 and 2013, with the largest difference of 27% (558.70 per 10,000 people vs 438.20) in 2013. Conclusions:We use national EHRs to produce estimates of burden of disease to produce detailed estimates by deprivation, ethnicity and geographical region. National EHRs have the potential to improve disease burden estimates at a local and global level and may serve as more automated, timely and precise inputs for policy making and global burden of disease estimation.

Background: Children born with major congenital anomalies (CAs) have lower academic achievement compared with their peers, but the existing evidence is restricted to a number of specific CAs. Objectives: To investigate academic outcomes at ages 11 and 16 in children with major isolated structural CAs and children with Down or Turner syndromes. Methods: This population-based cohort study linked data on approximately 11,000 school-aged children born with major CAs in 1994-2004 registered by four regional CA registries in England with education data from the National Pupil Database (NPD). The comparison group was a random sample of children without major CAs from the background population recorded in the NPD that were frequency matched (5:1) to children with CAs by birth year, sex and geographical area. Results: Overall, 71.9%, 73.0% and 80.9% of children with isolated structural CAs achieved the expected attainment level at age 11 compared to 78.3%, 80.6% and 86.7% of the comparison group in English language, Mathematics and Science, respectively. Children with nervous system CAs as a whole had the lowest proportion who achieved the expected attainment at age 11. At age 16, 46.9% of children with CAs achieved the expected level compared to 52.5% of their peers. Major CAs were associated with being up to 9% (95% confidence interval [CI] 8%, 11%) and 12% (95% CI 9%, 14%) less likely to achieve expected levels at ages 11 and 16, respectively, after adjustment for socioeconomic deprivation. Conclusions: Although many children with isolated CAs achieved the expected academic level at ages 11 and 16, they were at higher risk of underachievement compared to their peers. These stark yet cautiously encouraging results are important for counselling parents of children with specific CAs and also highlight the possible need for special education support to reduce potential academic difficulties.

Background During the COVID-19 pandemic, there was a reduction in hospital admissions for acute exacerbation of COPD (AECOPD), particularly due to viral triggers. However, with easing of lockdowns and reduced used of facemasks, the future pattern of AECOPD hospitalisation is unclear. Objective To assess the seasonal variation of AECOPD rate and triggers (viral, bacterial, eosinophilic) during a calendar year post pandemic (2022). Methodology We conducted an observational cohort study of patients hospitalised with AECOPD in Leicester, UK. Participants were prospectively recruited at time of admission and categorised as viral, bacterial, eosinophilic or others. Results 212 participants were recruited. Mean age was 67±10 years, 97(46%) were male, mean blood eosinophils count 0.22(±0.1) x109/L, with n=27(13%) on home oxygen. Admissions for AECOPD were highest in Spring 2022 (35.8% of all AECOPD) and lowest in winter months (14.6%). Bacterial (40.5%) and viral (24%) infections were the most common triggers. No difference was seen in triggers of exacerbation across seasons (p=0.48), though numerically viral triggers made up the highest proportion in Spring (25%) and Summer (27%) in contrast to Winter (13%) (see figure 1). Rhinovirus was the most frequent cause among all viral PCR-confirmed exacerbations (p=0.005). The proportion of patients hospitalised for >4 days was significantly different between triggers (Bacterial 72%, Viral 57%, Eosinophilic 54%, Others 47%, p=0.038). Conclusion Typical seasonal variation in hospitalisation for AECOPD was lost during 2022, following two years of pandemic lock-down and management. It remains to be seen if seasonality will return in future years

BACKGROUND:Congenital anomalies are a leading cause of childhood morbidity, but little is known about the long-term outcomes.OBJECTIVE:To quantify the burden of disease in childhood for children with congenital anomalies by assessing the risk of hospitalisation, the number of days spent in hospital and proportion of children with extended stays (≥10 days).METHODS:European population-based record-linkage study in 11 regions in eight countries including children with congenital anomalies (EUROCAT children) and without congenital anomalies (reference children) living in the same regions. The children were born between 1995 and 2014 and were followed to their tenth birthday or 31/12/2015. European meta-analyses of the outcome measures were performed by two age groups, <1 year and 1-4 years.RESULTS:99,416 EUROCAT children and 2,021,772 reference children were linked to hospital databases. Among EUROCAT children, 85% (95%-CI: 79-90%) were hospitalised in the first year and 56% (95%-CI: 51-61%) at ages 1-4 years, compared to 31% (95%-CI: 26-37%) and 25% (95%-CI: 19-31%) of the reference children. Median length of stay was 2-3 times longer for EUROCAT children in both age groups. The percentages of children with extended stays (≥10 days) in the first year were 24% (95%-CI: 20-29%) for EUROCAT children and 1% (95%-CI: 1-2%) for reference children. The median length of stay varied greatly between congenital anomaly subgroups, with children with gastrointestinal anomalies and congenital heart defects having the longest stays.CONCLUSIONS:Children with congenital anomalies were more frequently hospitalised and median length of stay was longer. The outlook improves after the first year. Parents of children with congenital anomalies should be informed about the increased hospitalisations required for their child's care and the impact on family life and siblings, and they should be adequately supported.

Innovative testing approaches and care pathways are required to meet global hepatitis B virus (HBV) and hepatitis C virus (HCV) elimination goals. Routine blood‐borne virus (BBV) testing in emergency departments (EDs) in high‐prevalence areas is suggested by the European Centre for Disease Prevention and Control (ECDC) but there is limited evidence for this. Universal HIV testing in our ED according to UK guidance has been operational since 2015. We conducted a real‐world service evaluation of a modified electronic patient record (EPR) system to include opportunistic opt‐out HBV/reflex‐HCV tests for any routine blood test orders for ED attendees aged ≥16 years. Reactive laboratory results were communicated directly to specialist clinical teams. Our model for contacting patients requiring linkage to care (new diagnoses/known but disengaged) evolved from initially primarily hospital‐led to collaborating with regional health and community service networks. Over 11 months, 81,088 patients attended the ED; 36,865 (45.5%) had a blood test. Overall uptake for both HBV and HCV testing was 75%. Seroprevalence was 0.9% for hepatitis B surface antigen (HBsAg) and 0.9% for HCV antigen (HCV‐Ag). 79% of 140 successfully contacted HBsAg+patients required linkage to care, of which 87% engaged. 76% of 130 contactable HCV‐Ag+patients required linkage, 52% engaged. Our results demonstrate effectiveness and sustainability of universal ED EPR opt‐out HBV/HCV testing combined with comprehensive linkage to care pathways, allowing care provision particularly for marginalized at‐risk groups with limited healthcare access. The findings support the ECDC BBV testing guidance and may inform future UK hepatitis testing guidance.

Introduction: Earlier diagnosis and treatment may improve health-related outcomes for adults with chronic breathlessness. Aims: To investigate the impact of a structured diagnostic pathway versus usual care for adults with chronic breathlessness. Methods: Ten family practices were cluster randomised to a structured diagnostic pathway including a panel of early investigations (intervention group [IG]) or usual care (UC). Patients were opportunistically recruited if eligible: ≥40 years old, first presentation of chronic breathlessness and no prior diagnosis for symptoms. Patient reported outcome measures (PROMs) for breathlessness, mental health and health-related quality of life were collected at baseline and 12 months. Results: 48 patients (65% female, mean [SD] age 66[11] years, BMI 31.2[6.5], median [IQR] MRC dyspnoea scale 2 [2-3]) were recruited Nov 2019 to Feb 2021. 40/48 (83%) participants returned questionnaires at 12 months: n=19 UC, n=21 IG. The IG had a median (IQR) of 8 (7-9) tests compared with 5 (3-6) tests in UC within three months. A comparison of the PROMs between groups are shown in Figure 1. Conclusion: In this feasibility study, the IG underwent more investigations compared with UC and results indicate patient level benefit. However, the IG were more symptomatic at baseline. An adequately powered clinical trial is needed to investigate further.

Background Inpatients experiencing homelessness are often discharged to unstable accommodation or the street, which may increase the risk of readmission. Methods We conducted a cohort study of 2772 homeless patients discharged after an emergency admission at 78 hospitals across England between November 2013 and November 2016. For each individual, we selected a housed patient who lived in a socioeconomically deprived area, matched on age, sex, hospital, and year of discharge. Counts of emergency readmissions, planned readmissions, and Accident and Emergency (A&E) visits post-discharge were derived from national hospital databases, with a median of 2.8 years of follow-up. We estimated the cumulative incidence of readmission over 12 months, and used negative binomial regression to estimate rate ratios. Results After adjusting for health measured at the index admission, homeless patients had 2.49 (95% CI 2.29 to 2.70) times the rate of emergency readmission, 0.60 (95% CI 0.53 to 0.68) times the rate of planned readmission and 2.57 (95% CI 2.41 to 2.73) times the rate of A&E visits compared with housed patients. The 12-month risk of emergency readmission was higher for homeless patients (61%, 95% CI 59% to 64%) than housed patients (33%, 95% CI 30% to 36%); and the risk of planned readmission was lower for homeless patients (17%, 95% CI 14% to 19%) than for housed patients (30%, 95% CI 28% to 32%). While the risk of emergency readmission varied with the reason for admission for housed patients, for example being higher for admissions due to cancers than for those due to accidents, the risk was high across all causes for homeless patients. Conclusions Hospital patients experiencing homelessness have high rates of emergency readmission that are not explained by health. This highlights the need for discharge arrangements that address their health, housing and social care needs.

Background: Google Trends data are increasingly used by researchers as an indicator of population mental health, but few studies have investigated the validity of this approach. Methods: Relative search volumes (RSV) for the topics depression, anxiety, self-harm, suicide, suicidal ideation, loneliness, and abuse were obtained from Google Trends. We used graphical and time-series approaches to compare daily trends in searches for these topics against population measures of these outcomes recorded using validated scales (PHQ-9; GAD-7; UCLA-3) in a weekly survey (n=~70,000) of the impact COVID-19 on psychological and social experiences in the UK population (12/03/2020 to 21/08/ 2020). Results: Self-reported levels of depression, anxiety, suicidal ideation, self-harm, loneliness and abuse decreased during the period studied. There was no evidence of an association between self-reported anxiety, self-harm, abuse and RSV on Google Trends. Trends in reported depression symptoms and suicidal ideation declined over the study period, whereas Google topic RSV increased (p=0.03 and p=0.04 respectively). There was some evidence that suicidal ideation searches preceded reported self-harm (p=0.05), but graphical evidence suggested this was an inverse association. However, there was statistical and graphical evidence that self-report and Google searches for loneliness (p<0.001) tracked one another. Limitations: No age/sex breakdown of Google Trends data are available. Survey respondents were not representative of the UK population and no pre-pandemic data were available. Conclusion: Google Trends data do not appear to be a useful indicator of changing levels of population mental health during a public health emergency, but may have some value as an indicator of loneliness.

Background: The 2020 Coronavirus pandemic is a major international public health challenge. Governments have taken public health protection measures to reduce the spread of the virus through non-pharmalogical measures. The impact of the pandemic and the public health response on individual and population mental health is unknown. Methods: We used Google Trends data (1 Jan 2020 - 30 Mar 2020) to investigate the impact of the pandemic and government measures to curb it on people’s concerns, as indexed by changes in search frequency for topics indicating mental distress, social and economic stressors and mental health treatment-seeking. We explored the changes of key topics in Google trends in Italy, Spain, USA, UK, and Worldwide in relation to sentinel events during the pandemic. Results: Globally there appears to be significant concerns over the financial and work-related consequences of the pandemic, with some evidence that levels of fear are rising. Conversely relative searching for topics related to depression and suicide fell after the pandemic was announced, with some evidence that searches for the latter have risen recently. Concerns over education and access to medication appear to be particular social stressors. Whilst searches for face-to-face treatments have declined, those for self-care have risen. Conclusions: Monitoring Google trends shows promise as a means of tracking changing public concerns. In weeks to come it may enable policy makers to assess the impact of their interventions including those aiming to limit negative consequences, such as government funded financial safety nets.

Objectives To identify: (i) risk of cardiovascular disease (CVD) in homeless versus housed individuals and (ii) interventions for CVD in homeless populations. Methods We conducted a systematic literature review in EMBASE until December 2018 using a search strategy for observational and interventional studies without restriction regarding languages or countries. Meta-analyses were conducted, where appropriate and possible. Outcome measures were all-cause and CVD mortality, and morbidity. Results Our search identified 17 articles (6 case-control, 11 cohort) concerning risk of CVD and none regarding specific interventions. Nine were included to perform a meta-analysis. The majority (13/17, 76.4%) were high quality and all were based in Europe or North America, including 765 459 individuals, of whom 32 721 were homeless. 12/17 studies were pre-2011. Homeless individuals were more likely to have CVD than non-homeless individuals (pooled OR 2.96; 95% CI 2.80 to 3.13; p<0.0001; heterogeneity p<0.0001; I 2 =99.1%) and had increased CVD mortality (age-standardised mortality ratio range: 2.6–6.4). Compared with non-homeless individuals, hypertension was more likely in homeless people (pooled OR 1.38–1.75, p=0.0070; heterogeneity p=0.935; I 2 =0.0%). Conclusions Homeless people have an approximately three times greater risk of CVD and an increased CVD mortality. However, there are no studies of specific pathways/interventions for CVD in this population. Future research should consider design and evaluation of tailored interventions or integrating CVD into existing interventions.

Background: The 2020 Coronavirus pandemic is a major international public health challenge. Governments have taken public health protection measures to reduce the spread of the virus through non-pharmalogical measures. The impact of the pandemic and the public health response on individual and population mental health is unknown. Methods: We used Google Trends data (1 Jan 2020 - 30 Mar 2020) to investigate the impact of the pandemic and government measures to curb it on people’s concerns, as indexed by changes in search frequency for topics indicating mental distress, social and economic stressors and mental health treatment-seeking. We explored the changes of key topics in Google trends in Italy, Spain, USA, UK, and Worldwide in relation to sentinel events during the pandemic. Results: Globally there appears to be significant concerns over the financial and work-related consequences of the pandemic, with some evidence that levels of fear are rising. Conversely relative searching for topics related to depression and suicide fell after the pandemic was announced, with some evidence that searches for the latter have risen recently. Concerns over education and access to medication appear to be particular social stressors. Whilst searches for face-to-face treatments have declined, those for self-care have risen. Conclusions: Monitoring Google trends shows promise as a means of tracking changing public concerns. In weeks to come it may enable policy makers to assess the impact of their interventions including those aiming to limit negative consequences, such as government funded financial safety nets.

Homelessness is increasing globally. The risk and burden of cardiovascular disease (CVD) are higher in homeless than in housed individuals but the population-based analyses, required for planning of effective interventions and policies, are lacking. Using national electronic health records (EHRs), we investigated prevalence, incidence and outcomes across a range of CVDs among homeless individuals. Using linked UK primary care EHR and validated phenotypes, we identified homeless individuals aged ≥16 years between 1998 and 2019, and age- and sex-matched housed controls in a 1:5 ratio. For twelve CVDs (stable angina; unstable angina; myocardial infarction; sudden cardiac death or cardiac arrest; unheralded coronary death; heart failure; transient ischaemic attack; ischaemic stroke or stroke not further specified; subarachnoid haemorrhage; intracerebral haemorrhage; peripheral arterial disease; abdominal aortic aneurysm), we estimated prevalence, incidence and 1-year mortality risks, comparing homeless and housed groups. We identified 8492 homeless individuals and 32134 matched controls. Comorbidities and risk factors were more prevalent in the homeless group, e.g. smoking: 78.1% vs 48.3% and atrial fibrillation: 9.9% vs 8.6%, p<0.001. CVD prevalence (11.6% and 6.5%), incidence (e.g. incidence rate ratio, 3.36, 1.99–5.66 and 2.18, 1.50–3.16 in men and women, respectively, aged <35 years), and 1-year mortality risk were higher (adjusted hazard ratio 2.30, 1.70–3.12), and onset was earlier (difference: 4.6, 2.8–6.3 years, p<0.001), in homeless, compared with housed people. Other than cerebrovascular and peripheral vascular diseases in women (where numbers of events were small), homeless individuals had higher incidence of CVD in all three arterial territories than housed people. CVD in homeless individuals has high prevalence, incidence and 1-year mortality risk with early onset, and high burden of risk factors. Health and social care strategies in inclusion health should reflect this high burden of treatable risk factors and disease. Incidence of CVD in homeless individuals Type of funding source: Public grant(s) – National budget only. Main funding source(s): National Institute of Health Research

Background: The coronavirus disease 2019 (COVID-19) pandemic is the largest acute public health emergency of this century. Government intervention to contain the virus focuses on non-pharmacological approaches such as physical distancing/lockdown (stay-at-home orders). As the situation develops, the impact of these measures on mental health and coping strategies in individuals and the population is unknown. Methods: We used Google Trends data (01 Jan 2020 to 09 Jun 2020) to explore the changing pattern of public concern in the UK to government measures as indexed by changes in search frequency for topics related to mental distress as well as coping and resilience. We explored the changes of specific topics in relation to key dates during the pandemic. In addition, we examined terms whose search frequency increased most. Results: Following lockdown, public concerns - as indexed by relative search trends - were directly related to COVID-19 and practicalities such as ‘furlough’ (paid leave scheme for people in employment) in response to the pandemic. Over time, searches with the most substantial growth were no longer directly or indirectly related to COVID-19. In contrast to relatively stable rates of searches related to mental distress, the topics that demonstrated a sustained increase were those associated with coping and resilience such as exercise and learning new skills. Conclusions: Google Trends is an expansive dataset which enables the investigation of population-level search activity as a proxy for public concerns. It has potential to enable policy makers to respond in real time to promote adaptive behaviours and deliver appropriate support.

Aims The risk and burden of cardiovascular disease (CVD) are higher in homeless than in housed individuals but population-based analyses are lacking. The aim of this study was to investigate prevalence, incidence and outcomes across a range of specific CVDs among homeless individuals. Methods and results Using linked UK primary care electronic health records (EHRs) and validated phenotypes, we identified homeless individuals aged >= 16 years between 1998 and 2019, and age- and sex-matched housed controls in a 1:5 ratio. For 12 CVDs (stable angina; unstable angina; myocardial infarction; sudden cardiac death or cardiac arrest; unheralded coronary death; heart failure; transient ischaemic attack; ischaemic stroke; subarachnoid haemorrhage; intracerebral haemorrhage; peripheral arterial disease; abdominal aortic aneurysm), we estimated prevalence, incidence, and 1-year mortality post-diagnosis, comparing homeless and housed groups. We identified 8492 homeless individuals (32 134 matched housed individuals). Comorbidities and risk factors were more prevalent in homeless people, e.g. smoking: 78.1% vs. 48.3% and atrial fibrillation: 9.9% vs. 8.6%, P < 0.001. CVD prevalence (11.6% vs. 6.5%), incidence (14.7 vs. 8.1 per 1000 person-years), and 1-year mortality risk [adjusted hazard ratio 1.64, 95% confidence interval (CI) 1.29-2.08, P < 0.001] were higher, and onset was earlier (difference 4.6, 95% CI 2.8-6.3 years, P < 0.001), in homeless, compared with housed people. Homeless individuals had higher CVD incidence in all three arterial territories than housed people. Conclusion CVD in homeless individuals has high prevalence, incidence, and 1-year mortality risk post-diagnosis with earlier onset, and high burden of risk factors. Inclusion health and social care strategies should reflect this high preventable and treatable burden, which is increasingly important in the current COVID-19 context. [GRAPHICS] .

Background: The coronavirus disease 2019 (COVID-19) pandemic is the largest acute public health emergency of this century Government intervention to contain the virus focuses on non-pharmacological approaches such as physical distancing/lockdown (stay-at-home orders) As the situation develops, the impact of these measures on mental health and coping strategies in individuals and the population is unknown Methods: We used Google Trends data (01 Jan 2020 to 09 Jun 2020) to explore the changing pattern of public concern in the UK to government measures as indexed by changes in search frequency for topics related to mental distress as well as coping and resilience We explored the changes of specific topics in relation to key dates during the pandemic In addition, we examined terms whose search frequency increased most Results: Following lockdown, public concerns - as indexed by relative search trends - were directly related to COVID-19 and practicalities such as ‘furlough’ (paid leave scheme for people in employment) in response to the pandemic Over time, searches with the most substantial growth were no longer directly or indirectly related to COVID-19 In contrast to relatively stable rates of searches related to mental distress, the topics that demonstrated a sustained increase were those associated with coping and resilience such as exercise and learning new skills Conclusions: Google Trends is an expansive dataset which enables the investigation of population-level search activity as a proxy for public concerns It has potential to enable policy makers to respond in real time to promote adaptive behaviours and deliver appropriate support

Background: Homeless hospital inpatients are often discharged to unstable accommodation or the street, which may increase the risk of readmission. Methods: We conducted a cohort study of 3,222 homeless patients discharged alive from hospitals across England between 2013 and 2016, with mean 2.4 years of follow-up. A comparison group of housed patients living in deprived areas was matched 1:1 on age group, sex, hospital and year of discharge. Counts of emergency re-admissions, planned re-admissions and A&E visits post-discharge were derived from national hospital databases. We reported readmission risk and used negative binomial regression to estimate rate ratios. Findings: After adjusting for health at study baseline, homeless patients had 3.77 (95% CI 3.46-4.10) times the rate of emergency readmission, 0.71 (0.63-0.81) times the rate of planned readmission, and 3.76 (3.53-4.01) times the rate of A&E visits compared to housed patients. The 12-month risks of readmission for homeless patients were 59% (57%-61%) for emergency readmission and 92% (91%-93%) for A&E visits, and these risks were similar regardless of the cause of the index admission. In contrast, the 12-month readmission risks for deprived housed patients were 20% (19%-21%) for emergency readmission and 57% (55%-59%) for A&E visits, varying widely according to the cause of index admission. The 12-month risk of planned readmission was similar for homeless and housed patients. Among homeless patients, those discharged in areas with a specialist step-down service had 0.82 (0.75-0.91; p<0.001) times the rate of A&E visits of those in areas without a step-down services, with no evidence of differences in planned (0.88; 0.73-1.06; p=0.140) or emergency re-admissions (1.08; 0.98-1.18; p=0.102). Interpretation: Homeless inpatients have high rates of emergency readmission use that are not explained by their health. This highlights the need for discharge arrangements that address health, housing and social care needs. Funding Statement: This study was supported by the National Institute for Health Research (NIHR) [Project number: 13/156/10 to HS & DR]. The authors also acknowledge the support from the Health Data Research (HDR) UK which receives its funding from HDR UK Ltd funded by the UK Medical Research Council, Engineering and Physical Sciences Research Council, Economic and Social Research Council, Department of Health and Social Care (England), Chief Scientist Office of the Scottish Government Health and Social Care Directorates, Health and Social Care Research and Development Division (Welsh Government), Public Health Agency (Northern Ireland), British Heart Foundation (BHF) and the Wellcome Trust. ACH’s salary is provided by Central and North West London NHS Community Trust. AS is funded by UCLH Foundation Trust. DL is funded by the NIHR [DRF-2018-11-ST2-016]. JN is part-funded by the National Institute for Health Research (NIHR) Biomedical Research Centre for Mental Health at South London and Maudsley NHS Foundation Trust and King's College London. RBl is supported by a UK Research and Innovation Fellowship funded by a grant from the Medical Research Council [MR/S003797/1]. SL is funded by NIHR [ICA-CDRF-2016-02-042]. RBy is supported the NIHR Applied Research Collaboration (ARC) South West Peninsula..Declaration of Interests: NH is medical director, and ACH is a trustee of the Pathway: Healthcare for homeless people charity. AS is Clinical Lead and Manager for Find and Treat. All other authors declare no conflicts of interest.Ethics Approval Statement: Collection of patient identifiers and data linkage were performed without explicit consent from participants due to the complexities in retrospectively identifying and obtaining consent, and because we wanted to use existing secondary data to examine mortality in this group. We engaged with people who had experience of homelessness and most felt that studies such as this are acceptable without consent, providing adequate data security measures are in place and studies have regulatory and ethical approval. This research was undertaken following approval (reference 16/CAG/0021) from the Secretary of State for Health through the Confidentiality Advisory Group (CAG). The Health Research Authority Research Ethics Committee approved the study (REC 16/EE/0018). In addition, local R&D approvals were obtained prior to local data collection at each of the Homeless Hospital Discharge Fund sites. After data linkage, we destroyed personal identifying data and undertook all analyses using the anonymised dataset outlined previously and in Figure 1. All study data were stored on the UCL Data Safe Haven, which has been certified to the ISO:27001:2013 information security standard and conforms to the NHS Information Governance Toolkit.