Automating incidence and prevalence analysis in open cohorts.

MOTIVATION: Data is increasingly used for improvement and research in public health, especially administrative data such as that collected in electronic health records. Patients enter and exit these typically open-cohort datasets non-uniformly; this can render simple questions about incidence and prevalence time-consuming and with unnecessary variation between analyses. We therefore developed methods to automate analysis of incidence and prevalence in open cohort datasets, to improve transparency, productivity and reproducibility of analyses. IMPLEMENTATION: We provide both a code-free set of rules for incidence and prevalence that can be applied to any open cohort, and a python Command Line Interface implementation of these rules requiring python 3.9 or later. GENERAL FEATURES: The Command Line Interface is used to calculate incidence and point prevalence time series from open cohort data. The ruleset can be used in developing other implementations or can be rearranged to form other analytical questions such as period prevalence. AVAILABILITY: The command line interface is freely available from https://github.com/THINKINGGroup/analogy_publication .

Using Repeated Measurements to Predict Cardiovascular Risk in Patients With Type 2 Diabetes Mellitus.

The QRISK cardiovascular disease (CVD) risk assessment model is not currently optimized for patients with type 2 diabetes mellitus (T2DM). We aim to identify if the abundantly available repeatedly measured data for patients with T2D improves the predictive capability of QRISK to support the decision-making process regarding CVD prevention in patients with T2DM. We identified patients with T2DM aged 25 to 85, not on statin treatment and without pre-existing CVD from the IQVIA Medical Research Data United Kingdom primary care database and then followed them up until the first diagnosis of CVD, ischemic heart disease, or stroke/transient ischemic attack. We included traditional, nontraditional risk factors and relevant treatments for our analysis. We then undertook a Cox's hazards model accounting for time-dependent covariates to estimate the hazard rates for each risk factor and calculated a 10-year risk score. Models were developed for males and females separately. We tested the performance of our models using validation data and calculated discrimination and calibration statistics. The study included 198,835 (180,143 male with 11,976 outcomes and 90,466 female with 8,258 outcomes) patients. The 10-year predicted survival probabilities for females was 0.87 (0.87 to 0.87), whereas the observed survival estimates from the Kaplan-Meier curve for all female models was 0.87 (0.86 to 0.87). The predicted and observed survival estimates for males were 0.84 (0.84 to 0.84) and 0.84 (0.83 to 0.84) respectively. The Harrell's C-index of all female models and all male models were 0.71 and 0.69 respectively. We found that including time-varying repeated measures, only mildly improved CVD risk prediction for T2DM patients in comparison to the current practice standard. We advocate for further research using time-varying data to identify if the involvement of further covariates may improve the accuracy of currently accepted prediction models.

The cost of primary care consultations associated with long COVID in non-hospitalised adults: a retrospective cohort study using UK primary care data.

BACKGROUND: The economic impact of managing long COVID in primary care is unknown. We estimated the costs of primary care consultations associated with long COVID and explored the relationship between risk factors and costs. METHODS: Data were obtained on non-hospitalised adults from the Clinical Practice Research Datalink Aurum primary care database. We used propensity score matching with an incremental cost method to estimate additional primary care consultation costs associated with long COVID (12 weeks after COVID-19) at an individual and UK national level. We applied multivariable regression models to estimate the association between risk factors and consultations costs beyond 12 weeks from acute COVID-19. RESULTS: Based on an analysis of 472,173 patients with COVID-19 and 472,173 unexposed individuals, the annual incremental cost of primary care consultations associated with long COVID was £2.44 per patient and £23,382,452 at the national level. Among patients with COVID-19, a long COVID diagnosis and reporting of longer-term symptoms were associated with a 43% and 44% increase in primary care consultation costs respectively, compared to patients without long COVID symptoms. Older age, female sex, obesity, being from a white ethnic group, comorbidities and prior consultation frequency were all associated with increased primary care consultation costs. CONCLUSIONS: The costs of primary care consultations associated with long COVID in non-hospitalised adults are substantial. Costs are significantly higher among those diagnosed with long COVID, those with long COVID symptoms, older adults, females, and those with obesity and comorbidities.

Mixed methods study protocol for combining stakeholder-led rapid evaluation with near real-time continuous registry data to facilitate evaluations of quality of care in intensive care units.

Background: Improved access to healthcare in low- and middle-income countries (LMICs) has not equated to improved health outcomes. Absence or unsustained quality of care is partly to blame. Improving outcomes in intensive care units (ICUs) requires delivery of complex interventions by multiple specialties working in concert, and the simultaneous prevention of avoidable harms associated with the illness and the treatment interventions. Therefore, successful design and implementation of improvement interventions requires understanding of the behavioural, organisational, and external factors that determine care delivery and the likelihood of achieving sustained improvement. We aim to identify care processes that contribute to suboptimal clinical outcomes in ICUs located in LMICs and to establish barriers and enablers for improving the care processes. Methods: Using rapid evaluation methods, we will use four data collection methods: 1) registry embedded indicators to assess quality of care processes and their associated outcomes; 2) process mapping to provide a preliminary framework to understand gaps between current and desired care practices; 3) structured observations of processes of interest identified from the process mapping and; 4) focus group discussions with stakeholders to identify barriers and enablers influencing the gap between current and desired care practices. We will also collect self-assessments of readiness for quality improvement. Data collection and analysis will be led by local stakeholders, performed in parallel and through an iterative process across eight countries: Kenya, India, Malaysia, Nepal, Pakistan, South Africa, Uganda and Vietnam. Conclusions: The results of our study will provide essential information on where and how care processes can be improved to facilitate better quality of care to critically ill patients in LMICs; thus, reduce preventable mortality and morbidity in ICUs. Furthermore, understanding the rapid evaluation methods that will be used for this study will allow other researchers and healthcare professionals to carry out similar research in ICUs and other health services.

Prevalence and demographic variation of cardiovascular, renal, metabolic, and mental health conditions in 12 million english primary care records.

BACKGROUND: Primary care electronic health records (EHR) are widely used to study long-term conditions in epidemiological and health services research. Therefore, it is important to understand how well the recorded prevalence of these conditions in EHRs, compares to other reliable sources overall, and varies by socio-demographic characteristics. We aimed to describe the prevalence and socio-demographic variation of cardiovascular, renal, and metabolic (CRM) and mental health (MH) conditions in a large, nationally representative, English primary care database and compare with prevalence estimates from other population-based studies. METHODS: This was a cross-sectional study using the Clinical Practice Research Datalink (CPRD) Aurum primary care database. We calculated prevalence of 18 conditions and used logistic regression to assess how this varied by age, sex, ethnicity, and socio-economic status. We searched the literature for population prevalence estimates from other sources for comparison with the prevalences in CPRD Aurum. RESULTS: Depression (16.0%, 95%CI 16.0-16.0%) and hypertension (15.3%, 95%CI 15.2-15.3%) were the most prevalent conditions among 12.4 million patients. Prevalence of most conditions increased with socio-economic deprivation and age. CRM conditions, schizophrenia and substance misuse were higher in men, whilst anxiety, depression, bipolar and eating disorders were more common in women. Cardiovascular risk factors (hypertension and diabetes) were more prevalent in black and Asian patients compared with white, but the trends in prevalence of cardiovascular diseases by ethnicity were more variable. The recorded prevalences of mental health conditions were typically twice as high in white patients compared with other ethnic groups. However, PTSD and schizophrenia were more prevalent in black patients. The prevalence of most conditions was similar or higher in the primary care database than diagnosed disease prevalence reported in national health surveys. However, screening studies typically reported higher prevalence estimates than primary care data, especially for PTSD, bipolar disorder and eating disorders. CONCLUSIONS: The prevalence of many clinically diagnosed conditions in primary care records closely matched that of other sources. However, we found important variations by sex and ethnicity, which may reflect true variation in prevalence or systematic differences in clinical presentation and practice. Primary care data may underrepresent the prevalence of undiagnosed conditions, particularly in mental health.

Cardiometabolic screening and monitoring in patients prescribed antipsychotic drugs in primary care: A population-based cohort study.

BACKGROUND: This study aimed to investigate the level of guideline adherence for cardiometabolic health monitoring for patients prescribed antipsychotic medicines in UK primary care. METHODS: In this population-based retrospective open cohort study, we used dataset of patients from the IQVIA Medical Research Data (IMRD) database between 1st January 2003 to 31st December 2018. Clinical Read codes were used to identify a cohort of adult patients with a diagnosis of Schizophrenia and at least four prescriptions of an anti-psychotic medication within 12 months of diagnosis. We then extracted data in relation to monitoring of cardiometabolic parameters (body compositions, lipids, and glucose outcomes) at baseline, then at six weeks, 12 weeks, and then 12 months. The frequency of outcome monitoring was described using descriptive statistics. FINDINGS: A total of 11,435 patients were eligible and of them (n = 9707; 84·8%) were prescribed second-generation antipsychotics (SGAs). Only a small portion of the cohort (≈2·0%) received complete monitoring (at time points) for certain outcomes. Just over half the patients (n = 6599, 52%) had evidence of any cardiometabolic baseline testing for any of the study outcomes and the high majority had at least one abnormal lab value at baseline (n = 4627, 96·7%). INTERPRETATION: In UK primary care, cardiometabolic monitoring practices among patients prescribed antipsychotics remain suboptimal. There is a need to promote guideline adherence to prevent adverse outcomes in antipsychotic users.

Seasonal variation of serum potassium and related prescription pattern: an ecological time series.

Aims To assess if ambient temperature-related effects on serum potassium levels impact clinical decision-making. Methods This study is an ecological time series consisiting of 1 218 453 adult patients with at least one ACE inhibitor (ACEI) prescription who participate in a large UK primary care dataset.Descriptive statistics and a quasi-Poisson regression model using time series data at regular time intervals (monthly) were undertaken to examine the association between potassium measurements and ACEI/potassium supplement prescriptions. RESULTS: It is noted that correlating with lower ambient temperature, serum potassium values follow a seasonal pattern; peaks in winter months and troughs in summer. During summer months, there are clear annual spikes in the number of potassium prescriptions suggesting a change in prescribing practice during periods of potentially spurious hyperkalaemia. The converse pattern is seen in the ACEI prescription proportion which spikes annually during the winter period with lower average ambient temperatures. Our time series modelling demonstrated that each one unit increase in potassium is associated with a 33% increased rate of ACEI prescriptions (risk ratio, RR 1.33; 95% CI 1.12 to 1.59) and 63% decreased rate of potassium supplements (RR 0.37; 95% CI 0.32 to 0.43). CONCLUSIONS: Our findings highlight the seasonal pattern in serum potassium and we observe a corresponding alteration in prescribing practice for potassium sensitive medications. These findings demonstrate the importance of educating clinicians on the presence of seasonal potassium variability in addition to standard measurement error, and its potential impact on their prescribing activity.

Exposure to Domestic Abuse and the Subsequent Development of Atopic Disease in Women.

BACKGROUND: Exposure to domestic violence and abuse (DVA) is a global public health issue associated with substantial morbidity and mortality. There are few high-quality studies that assess the impact of DVA exposure on the development of atopic disease. OBJECTIVE: To examine the association between exposure to DVA and the subsequent development of atopy. METHODS: In this population-based, retrospective, open cohort study, we identified women with no history of atopic disease between January 1, 1995 and September 30, 2019 from IQVIA Medical Research Data, an anonymized UK primary care dataset. We used clinical codes to identify exposed patients (those with a code identifying exposure to DVA; n = 13,852) and unexposed patients (n = 49,036), who were matched by age and deprivation quintile. Cox proportional hazards regression was used to calculate hazard ratios (HRs) (with 95% CIs) of developing atopic disease: asthma, atopic eczema, or allergic rhinoconjunctivitis. RESULTS: During the study period, 967 exposed women (incidence rate, 20.10/1,000 person-years) developed atopic disease, compared with 2,607 unexposed women (incidence rate, 13.24/1,000 person-years). This translated to an adjusted HR of 1.52 (95% CI, 1.41-1.64) accounting for key confounders; asthma (adjusted HR = 1.69; 95% CI, 1.44-1.99), atopic eczema (adjusted HR = 1.40; 95% CI, 1.26-1.56), and allergic rhinoconjunctivitis (adjusted HR = 1.63; 95% CI, 1.45-1.84). CONCLUSIONS: Domestic violence and abuse is a significant global public health issue. These results demonstrate a significant associated risk for developing atopic disease. Public health approaches to the prevention and detection of DVA are necessary to reduce the associated ill health burden.

Associations between primary care recorded cannabis use and mental ill health in the UK: a population-based retrospective cohort study using UK primary care data.

BACKGROUND: Cannabis use is a global public health issue associated with increased risks of developing mental health disorders, especially in young people. We aimed to investigate the relationships between cannabis exposure and risks of receiving mental illness diagnoses or treatment as outcomes. METHODS: A population based, retrospective, open cohort study using patients recorded in 'IQVIA medical research data', a UK primary care database. Read codes were used to confirm patients with recorded exposure to cannabis use who were matched up to two unexposed patients. We examined the risk of developing three categories of mental ill health: depression, anxiety or serious mental illness (SMI). RESULTS: At study entry, the exposed cohort had an increased likelihood of having experienced mental ill health [odds ratio (OR) 4.13; 95% confidence interval (CI) 3.99-4.27] and mental ill health-related prescription (OR 2.95; 95% CI 2.86-3.05) compared to the unexposed group. During the study period we found that exposure to cannabis was associated with an increased risk of developing any mental disorder [adjusted hazard ratio (aHR) 2.73; 95% CI 2.59-2.88], also noted when examining by subtype of disorder: anxiety (aHR 2.46; 95% CI 2.29-2.64), depression (aHR 2.34; 95% CI 2.20-2.49) and SMI (aHR 6.41; 95% CI 5.42-7.57). These results remained robust in sensitivity analyses. CONCLUSION: These findings point to the potential need for a public health approach to the management of people misusing cannabis. However, there is a gross under-recording of cannabis use in GP records, as seen by the prevalence of recorded cannabis exposure substantially lower than self-reported survey records.

Metformin and risk of age-related macular degeneration in individuals with type 2 diabetes: a retrospective cohort study.

BACKGROUND: Age-related macular degeneration (AMD) in its late stages is a leading cause of sight loss in developed countries. Some previous studies have suggested that metformin may be associated with a reduced risk of developing AMD, but the evidence is inconclusive. AIMS: To explore the relationship between metformin use and development of AMD among patients with type 2 diabetes in the UK. METHODS: A large, population-based retrospective open cohort study with a time-dependent exposure design was carried out using IQVIA Medical Research Data, 1995-2019. Patients aged ≥40 with diagnosed type 2 diabetes were included.The exposed group was those prescribed metformin (with or without any other antidiabetic medications); the comparator (unexposed) group was those prescribed other antidiabetic medications only. The exposure status was treated as time varying, collected at 3-monthly time intervals.Extended Cox proportional hazards regression was used to calculate the adjusted HRs for development of the outcome, newly diagnosed AMD. RESULTS: A total of 173 689 patients, 57% men, mean (SD) age 62.8 (11.6) years, with incident type 2 diabetes and a record of one or more antidiabetic medications were included in the study. Median follow-up was 4.8 (IQR 2.3-8.3, range 0.5-23.8) years. 3111 (1.8%) patients developed AMD. The adjusted HR for diagnosis of AMD was 1.02 (95% CI 0.92 to 1.12) in patients prescribed metformin (with or without other antidiabetic medications) compared with those prescribed any other antidiabetic medication only. CONCLUSION: We found no evidence that metformin was associated with risk of AMD in primary care patients requiring treatment for type 2 diabetes.

Sodium-glucose cotransporter-2 inhibitors and the risk of gout in patients with type 2 diabetes mellitus: A propensity-score-matched, new-user design study with an active comparator using the IQVIA Medical Research Data UK database.

AIM: To conduct a pharmacoepidemiological study to explore the association between sodium-glucose cotransporter-2 (SGLT2) inhibitors and gout in patients with type 2 diabetes mellitus (T2DM). MATERIALS AND METHODS: A retrospective open cohort study using the IQVIA Medical Research Data UK database was performed between November 1, 2012 and December 31, 2018, estimating the risk of gout in patients with T2DM who were new users of SGLT2 inhibitors, compared to propensity-score-matched new users of dipeptidyl peptidase-4 (DPP-4) inhibitors. RESULTS: A total of 85 incident cases of gout were recorded over 30 389 person-years of observation in 13 617 new users of SGLT2 inhibitors and 29 426 new users of DPP-4 inhibitors. Crude incidence rates (IRs) per 1000 person-years were 2.90 and 2.47 for new users of SGLT2 inhibitors and DPP-4 inhibitors, respectively. The unadjusted hazard ratio (HR) was 1.18 (95% confidence interval [CI] 0.76-1.83). The adjusted HR was 1.20 (95% CI 0.77-1.86). In the at-treatment analysis, crude IRs per 1000 person-years were found to be 2.68 and 2.53 for SGLT2 inhibitor and DPP-4 inhibitor users, respectively. In the adjusted model, the adjusted HR was 1.3 (95% CI 0.90-2.29). Sensitivity analyses did not change the findings. CONCLUSIONS: In this nationwide study, no difference in the incidence of gout was documented in patients treated with SGLT2 inhibitors compared to DPP-4 inhibitor users. This neutral finding remained consistent in sensitivity analyses.

Association between childhood maltreatment and atopy in the UK: A population based retrospective cohort study.

Background: Childhood maltreatment affects over one in three children worldwide and is associated with a substantial disease burden. This study explores the association between childhood maltreatment and the development of atopic disease. Methods: We did a population-based retrospective matched open cohort study using participating general practices between 1st January 1995 and 30th September 2019. Read codes were utilised to identify patients exposed to childhood maltreatment (either suspected or confirmed) who were matched to up to four unexposed patients by age, sex, general practice, and Townsend deprivation quintile. Cox regression analysis was used to calculate adjusted (age, sex, Townsend deprivation quintile) hazard ratios (aHR) for development of atopy (asthma, atopic dermatitis, or allergic rhino conjunctivitis) during follow up in those without atopy at study entry. Results: 183,897 exposed patients were matched to 621,699 unexposed patients. During the follow up period, 18,555 patients (incidence rate (IR) 28.18 per 1000 person-years) in the exposed group developed atopic disease compared to the 68,368 (IR 23.58 per 1000 person-years) in the unexposed group, translating to an adjusted HR of 1.14 (95% CI 1.12-1.15). Notably, the risk of developing asthma was aHR 1.42 (95% CI 1.37-1.46). Associations were more pronounced in analyses restricted to females and confirmed cases of childhood maltreatment only. Interpretation: Considering the substantial health burden associated with childhood maltreatment, it is important to implement public health policies aimed at enhancing: 1) detection and primary prevention of childhood maltreatment, 2) secondary and tertiary prevention interventions to reduce the burden of ill health associated with exposure to maltreatment and 3) clinical awareness of such associations and subsequent knowledge of management. Funding: None.

Glycemic outcomes in patients with type 2 diabetes after bariatric surgery compared with routine care: a population-based, real-world cohort study in the United Kingdom.

BACKGROUND: Clinical trials have shown that bariatric surgery (BS) is associated with better glycemic control and diabetes remission in patients with type 2 diabetes (T2D) compared with routine care. OBJECTIVE: We conducted a real-world population-based study examining the impact of BS on glycemic control and medications in patients with T2D. SETTING AND METHODS: This was a retrospective, matched, controlled cohort study conducted between January 1, 1990, and January 31, 2018, using IQVIA Medical Research Data, a primary care electronic records database. Adults with body mass index (BMI) ≥30 kg/m2 and T2D who had BS (surgical) were matched for age, sex, BMI, and diabetes duration to two controls (with T2D and no BS). RESULTS: A total of 1126 patients in the surgical group and 2219 patients in the control group were analyzed. Mean (standard deviation) age was 50.0 (9.3) years, 67.6% were women, baseline glycocylated hemoglobin (HbA1C) was 7.8% (1.7 mmol/mol), and diabetes duration was 4.7 years (range, 2.0-8.4 years). Over a median (interquartile range) follow-up of 3.6 years (1.7-5.9 years), a higher proportion of patients in the surgical group achieved an HbA1C of ≤6.0% than the control group (65.8% versus 22.8%). The surgical group showed a decrease in mean HbA1C of 1.5% (95% confidence interval [CI]: 1.4%-1.7%), 1.4% (1.2%-1.5%), and 1.3% (1.1%-1.5%) at 1-, 2-, and 3-year follow-up, respectively, whereas HbA1C increased in the control group. The proportion of patients receiving glucose-lowering medications decreased in the surgical group (92.2% to 66.5%) but increased in the control group (85.3% to 90.2%). CONCLUSION: BS is associated with significant improvement in glycemic control, achievement of normal HbA1C levels, and reduced need for glucose-lowering therapy in patients with T2D.

Long-term impact of pre-incision antibiotics on children born by caesarean section: a longitudinal study based on UK electronic health records.

BACKGROUND: Since changes in the national guidance in 2011, prophylactic antibiotics for women undergoing caesarean section are recommended prior to skin incision, rather than after the baby's umbilical cord has been clamped. Evidence from randomised controlled trials conducted outside the UK has shown that this reduces maternal infectious morbidity; however, the prophylactic antibiotics also cross the placenta, meaning that babies are exposed to them around the time of birth. Antibiotics are known to affect the gut microbiota of the babies, but the long-term effects of exposure to high-dose broad-spectrum antibiotics around the time of birth on allergy and immune-related diseases are unknown. OBJECTIVES: We aimed to examine whether or not in-utero exposure to antibiotics immediately prior to birth compared with no pre-incisional antibiotic exposure increases the risk of (1) asthma and (2) eczema in children born by caesarean section. DESIGN: This was a controlled interrupted time series study. SETTING: The study took place in primary and secondary care. PARTICIPANTS: Children born in the UK during 2006-18 delivered by caesarean section were compared with a control cohort delivered vaginally. INTERVENTIONS: In-utero exposure to antibiotics immediately prior to birth. MAIN OUTCOME MEASURES: Asthma and eczema in children in the first 5 years of life. Additional secondary outcomes, including other allergy-related conditions, autoimmune diseases, infections, other immune system-related diseases and neurodevelopmental conditions, were also assessed. DATA SOURCES: The Health Improvement Network (THIN) and the Clinical Practice Research Datalink (CPRD) primary care databases and the Hospital Episode Statistics (HES) database. Previously published linkage strategies were adapted to link anonymised data on mothers and babies in these databases. Duplicate practices contributing to both THIN and the CPRD databases were removed to create a THIN-CPRD data set. RESULTS: In the THIN-CPRD and HES data sets, records of 515,945 and 3,945,351 mother-baby pairs were analysed, respectively. The risk of asthma was not significantly higher in children born by caesarean section exposed to pre-incision antibiotics than in children whose mothers received post-cord clamping antibiotics, with an incidence rate ratio of 0.91 (95% confidence interval 0.78 to 1.05) for diagnosis of asthma in primary care and an incidence rate ratio of 1.05 (95% confidence interval 0.99 to 1.11) for asthma resulting in a hospital admission. We also did not find an increased risk of eczema, with an incidence rate ratio of 0.98 (95% confidence interval 0.94 to1.03) and an incidence rate ratio of 0.96 (95% confidence interval 0.71 to 1.29) for diagnosis in primary care and hospital admissions, respectively. LIMITATIONS: It was not possible to ascertain the exposure to pre-incision antibiotics at an individual level. The maximum follow-up of children was 5 years. CONCLUSIONS: There was no evidence that the policy change from post-cord clamping to pre-incision prophylactic antibiotics for caesarean sections during 2006-18 had an impact on the incidence of asthma and eczema in early childhood in the UK. FUTURE WORK: There is a need for further research to investigate if pre-incision antibiotics have any impact on developing asthma and other allergy and immune-related conditions in older children. STUDY REGISTRATION: This study is registered as researchregistry3736. FUNDING: This project was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 26, No. 30. See the NIHR Journals Library website for further project information.

WHAT WAS THE QUESTION?: Women giving birth by caesarean section are at risk of developing infections (such as wound infections) and are offered antibiotics at the time of their operation to reduce this risk. In 2011, the national guidelines changed from recommending antibiotics after cord clamping to giving them before the operation to further reduce the risk of maternal infection. During birth, the newborn gut is colonised by microbes. Antibiotics given to the mother before caesarean section can reach the baby through the placenta and disrupt the normal microbes that colonise the gut. These microbes are believed to play a role in the development of the immune system and altering the normal development of these microbes has been linked to children developing allergic conditions, such as asthma and eczema. This study investigated whether or not giving antibiotics before the caesarean section had a longer-term impact on children's health. WHAT DID WE DO?: We used routine NHS information already collected by hospitals and general practitioners about women who gave birth in the UK between 2006 and 2018, and their children. We compared the risk of asthma, eczema and other health conditions in the first 5 years after birth in children born by caesarean section before and after the change in hospital policies. We also compared their health with children born vaginally. WHAT DID WE FIND?: We found that there was no increased risk of asthma or eczema for children born by caesarean section after the policy decision in 2011 to give the mother antibiotics before the operation. WHAT DOES THIS MEAN?: The study findings provide further evidence for the current recommendation to give preventative antibiotics to women shortly before the caesarean section to reduce the overall risk of infections after birth.

Symptoms and risk factors for long COVID in non-hospitalized adults.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection is associated with a range of persistent symptoms impacting everyday functioning, known as post-COVID-19 condition or long COVID. We undertook a retrospective matched cohort study using a UK-based primary care database, Clinical Practice Research Datalink Aurum, to determine symptoms that are associated with confirmed SARS-CoV-2 infection beyond 12 weeks in non-hospitalized adults and the risk factors associated with developing persistent symptoms. We selected 486,149 adults with confirmed SARS-CoV-2 infection and 1,944,580 propensity score-matched adults with no recorded evidence of SARS-CoV-2 infection. Outcomes included 115 individual symptoms, as well as long COVID, defined as a composite outcome of 33 symptoms by the World Health Organization clinical case definition. Cox proportional hazards models were used to estimate adjusted hazard ratios (aHRs) for the outcomes. A total of 62 symptoms were significantly associated with SARS-CoV-2 infection after 12 weeks. The largest aHRs were for anosmia (aHR 6.49, 95% CI 5.02-8.39), hair loss (3.99, 3.63-4.39), sneezing (2.77, 1.40-5.50), ejaculation difficulty (2.63, 1.61-4.28) and reduced libido (2.36, 1.61-3.47). Among the cohort of patients infected with SARS-CoV-2, risk factors for long COVID included female sex, belonging to an ethnic minority, socioeconomic deprivation, smoking, obesity and a wide range of comorbidities. The risk of developing long COVID was also found to be increased along a gradient of decreasing age. SARS-CoV-2 infection is associated with a plethora of symptoms that are associated with a range of sociodemographic and clinical risk factors.

Machine learning of COVID-19 clinical data identifies population structures with therapeutic potential.

Clinical outcomes for patients with COVID-19 are heterogeneous and there is interest in defining subgroups for prognostic modeling and development of treatment algorithms. We obtained 28 demographic and laboratory variables in patients admitted to hospital with COVID-19. These comprised a training cohort (n = 6099) and two validation cohorts during the first and second waves of the pandemic (n = 996; n = 1011). Uniform manifold approximation and projection (UMAP) dimension reduction and Gaussian mixture model (GMM) analysis was used to define patient clusters. 29 clusters were defined in the training cohort and associated with markedly different mortality rates, which were predictive within confirmation datasets. Deconvolution of clinical features within clusters identified unexpected relationships between variables. Integration of large datasets using UMAP-assisted clustering can therefore identify patient subgroups with prognostic information and uncovers unexpected interactions between clinical variables. This application of machine learning represents a powerful approach for delineating disease pathogenesis and potential therapeutic interventions.

Risk of incident obstructive sleep apnoea in patients with type 1 diabetes: a population-based retrospective cohort study.

AIMS/HYPOTHESIS: People with type 2 diabetes are at increased risk of developing obstructive sleep apnoea. However, it is not known whether people with type 1 diabetes are also at an increased risk of obstructive sleep apnoea. This study aimed to examine whether people with type 1 diabetes are at increased risk of incident obstructive sleep apnoea compared with a matched cohort without type 1 diabetes. METHODS: We used a UK primary care database, The Health Improvement Network (THIN), to perform a retrospective cohort study between January 1995 and January 2018 comparing sleep apnoea incidence between patients with type 1 diabetes (exposed) and without type 1 diabetes (unexposed) (matched for age, sex, BMI and general practice). The outcome was incidence of obstructive sleep apnoea. Baseline covariates and characteristics were assessed at the start of the study based on the most recent value recorded prior to the index date. The Cox proportional hazards regression model was used to estimate unadjusted and adjusted hazard ratios, based on a complete-case analysis. RESULTS: In total, 34,147 exposed and 129,500 matched unexposed patients were included. The median follow-up time was 5.43 years ((IQR 2.19-10.11), and the mean BMI was 25.82 kg/m2 (SD 4.33). The adjusted HR for incident obstructive sleep apnoea in patients with type 1 diabetes vs those without type 1 diabetes was 1.53 (95% CI 1.25, 1.86; p<0.001). Predictors of incident obstructive sleep apnoea in patients with type 1 diabetes were older age, male sex, obesity, being prescribed antihypertensive or lipid-lowering drugs, atrial fibrillation and depression. CONCLUSIONS/INTERPRETATION: Individuals with type 1 diabetes are at increased risk of obstructive sleep apnoea compared with people without diabetes. Clinicians should suspect obstructive sleep apnoea in patients with type 1 diabetes if they are old, have obesity, are male, have atrial fibrillation or depression, or if they are taking lipid-lowering or antihypertensive drugs.

Long term impact of prophylactic antibiotic use before incision versus after cord clamping on children born by caesarean section: longitudinal study of UK electronic health records.

OBJECTIVE: To investigate the impact on child health up to age 5 years of a policy to use antibiotic prophylaxis for caesarean section before incision compared with after cord clamping. DESIGN: Observational controlled interrupted time series study. SETTING: UK primary and secondary care. PARTICIPANTS: 515 945 children born in 2006-18 with linked maternal records and registered with general practices contributing to two UK primary care databases (The Health Improvement Network and Clinical Practice Research Datalink), and 7 147 884 children with linked maternal records in the Hospital Episode Statistics database covering England, of which 3 945 351 were linked to hospitals that reported the year of policy change to administer prophylactic antibiotics for caesarean section before incision rather than after cord clamping. INTERVENTION: Fetal exposure to antibiotics shortly before birth (using pre-incision antibiotic policy as proxy) compared with no exposure. MAIN OUTCOME MEASURES: The primary outcomes were incidence rate ratios of asthma and eczema in children born by caesarean section when pre-incision prophylactic antibiotics were recommended compared with those born when antibiotics were administered post-cord clamping, adjusted for temporal changes in the incidence rates in children born vaginally. RESULTS: Prophylactic antibiotics administered before incision for caesarean section compared with after cord clamping were not associated with a significantly higher risk of asthma (incidence rate ratio 0.91, 95% confidence interval 0.78 to 1.05) or eczema (0.98, 0.94 to 1.03), including asthma and eczema resulting in hospital admission (1.05, 0.99 to 1.11 and 0.96, 0.71 to 1.29, respectively), up to age 5 years. CONCLUSIONS: This study found no evidence of an association between pre-incision prophylactic antibiotic use and risk of asthma and eczema in early childhood in children born by caesarean section.

Angiotensin-converting enzyme inhibitors and risk of age-related macular degeneration in individuals with hypertension.

AIMS: Several observational studies have examined the potential protective effect of angiotensin-converting enzyme inhibitor (ACE-I) use on the risk of age-related macular degeneration (AMD) and have reported contradictory results owing to confounding and time-related biases. We aimed to assess the risk of AMD in a base cohort of patients aged 40 years and above with hypertension among new users of ACE-I compared to an active comparator cohort of new users of calcium channel blockers (CCB) using data obtained from IQVIA Medical Research Data, a primary care database in the UK. METHODS: In this study, 53 832 and 43 106 new users of ACE-I and CCB were included between 1995 and 2019, respectively. In an on-treatment analysis, patients were followed up from the time of index drug initiation to the date of AMD diagnosis, loss to follow-up, discontinuation or switch to the comparator drug. A comprehensive range of covariates were used to estimate propensity scores to weight and match new users of ACE-I and CCB. Standardized mortality ratio weighted Cox proportional hazards model was used to estimate hazard ratios of developing AMD. RESULTS: During a median follow-up of 2 years (interquartile range 1-5 years), the incidence rate of AMD was 2.4 (95% confidence interval 2.2-2.6) and 2.2 (2.0-2.4) per 1000 person-years among the weighted new users of ACE-I and CCB, respectively. There was no association of ACE-I use on the risk of AMD compared to CCB use in either the propensity score weighted or matched, on-treatment analysis (adjusted hazard ratio: 1.07 [95% confidence interval 0.90-1.27] and 0.87 [0.71-1.07], respectively). CONCLUSION: We found no evidence that the use of ACE-I is associated with risk of AMD in patients with hypertension.

Therapies for Long COVID in non-hospitalised individuals: from symptoms, patient-reported outcomes and immunology to targeted therapies (The TLC Study).

INTRODUCTION: Individuals with COVID-19 frequently experience symptoms and impaired quality of life beyond 4-12 weeks, commonly referred to as Long COVID. Whether Long COVID is one or several distinct syndromes is unknown. Establishing the evidence base for appropriate therapies is needed. We aim to evaluate the symptom burden and underlying pathophysiology of Long COVID syndromes in non-hospitalised individuals and evaluate potential therapies. METHODS AND ANALYSIS: A cohort of 4000 non-hospitalised individuals with a past COVID-19 diagnosis and 1000 matched controls will be selected from anonymised primary care records from the Clinical Practice Research Datalink, and invited by their general practitioners to participate on a digital platform (Atom5). Individuals will report symptoms, quality of life, work capability and patient-reported outcome measures. Data will be collected monthly for 1 year.Statistical clustering methods will be used to identify distinct Long COVID-19 symptom clusters. Individuals from the four most prevalent clusters and two control groups will be invited to participate in the BioWear substudy which will further phenotype Long COVID symptom clusters by measurement of immunological parameters and actigraphy.We will review existing evidence on interventions for postviral syndromes and Long COVID to map and prioritise interventions for each newly characterised Long COVID syndrome. Recommendations will be made using the cumulative evidence in an expert consensus workshop. A virtual supportive intervention will be coproduced with patients and health service providers for future evaluation.Individuals with lived experience of Long COVID will be involved throughout this programme through a patient and public involvement group. ETHICS AND DISSEMINATION: Ethical approval was obtained from the Solihull Research Ethics Committee, West Midlands (21/WM/0203). Research findings will be presented at international conferences, in peer-reviewed journals, to Long COVID patient support groups and to policymakers. TRIAL REGISTRATION NUMBER: 1567490.