Nationwide Utilization of Danish Government Electronic letter system for increasing inFLUenza vaccine uptake (NUDGE-FLU): Study protocol for a nationwide randomized implementation trial.

BACKGROUND: Annual influenza vaccination is widely recommended in older adults and other high-risk groups including patients with cardiovascular disease. The real-world effectiveness of influenza vaccination is limited by suboptimal uptake and effective strategies for increasing vaccination rates are therefore needed. The purpose of this trial is to investigate whether behavioral nudges digitally delivered via the Danish nationwide mandatory governmental electronic letter system can increase influenza vaccination uptake among older adults. METHODS: The NUDGE-FLU trial is a randomized implementation trial randomizing all Danish citizens aged 65 years and above without an exemption from the Danish mandatory governmental electronic letter system to receive no digitally delivered behavioral nudge (usual care arm) or to receive one of 9 electronic letters (intervention arms) each leveraging different behavioral science strategies. The trial has randomized 964,870 participants with randomization clustered at the household level (n = 691,820 households). Intervention letters were delivered on September 16, 2022, and follow-up is currently ongoing. All trial data are captured using the nationwide Danish administrative health registries. The primary end point is the receipt of an influenza vaccine on or before January 1, 2023. The secondary end point is time to vaccination. Exploratory end points include clinical events such as hospitalization for influenza or pneumonia, cardiovascular events, all-cause hospitalization, and all-cause mortality. DISCUSSION: The nationwide randomized NUDGE-FLU trial is one of the largest implementation trials ever conducted and will provide important insights into effective communication strategies to maximize vaccination uptake among high-risk groups. TRIAL REGISTRATION: Clinicaltrials.gov: NCT05542004, registered September 15, 2022, https://clinicaltrials.gov/ct2/show/NCT05542004.

Clinical outcomes of myocarditis after SARS-CoV-2 mRNA vaccination in four Nordic countries: population based cohort study

Objective To investigate the clinical outcomes of myocarditis associated with mRNA vaccines against the SARS-CoV-2 virus compared with other types of myocarditis. Design Population based cohort study. Setting Nationwide register data from four Nordic countries (Denmark, Finland, Norway, and Sweden), from 1 January 2018 to the latest date of follow-up in 2022. Participants The Nordic myocarditis cohort;7292 individuals aged ≥12 years who had an incident diagnosis of myocarditis as a main or secondary diagnosis, in a population of 23 million individuals in Denmark, Finland, Norway, and Sweden. Main outcome measures Heart failure, or death from any cause within 90 days of admission to hospital for new onset myocarditis, and hospital readmission within 90 days of discharge to hospital for new onset myocarditis. Clinical outcomes of myocarditis associated with SARS-CoV-2 mRNA vaccination, covid-19 disease, and conventional myocarditis were compared. Results In 2018-22, 7292 patients were admitted to hospital with new onset myocarditis, with 530 (7.3%) categorised as having myocarditis associated with SARS-CoV-2 mRNA vaccination, 109 (1.5%) with myocarditis associated with covid-19 disease, and 6653 (91.2%) with conventional myocarditis. At the 90 day follow-up, 62, nine, and 988 patients had been readmitted to hospital in each group (vaccination, covid-19, and conventional myocarditis groups, respectively), corresponding to a relative risk of readmission of 0.79 (95% confidence interval 0.62 to 1.00) and 0.55 (0.30 to 1.04) for the vaccination type and covid-19 type myocarditis groups, respectively, compared with the conventional myocarditis group. At the 90 day follow-up, 27, 18, and 616 patients had a diagnosis of heart failure or died in the vaccination type, covid-19 type, and conventional myocarditis groups, respectively. The relative risk of heart failure within 90 days was 0.56 (95% confidence interval 0.37 to 0.85) and 1.48 (0.86 to 2.54) for myocarditis associated with vaccination and covid-19 disease, respectively, compared with conventional myocarditis;the relative risk of death was 0.48 (0.21 to 1.09) and 2.35 (1.06 to 5.19), respectively. Among patients aged 12-39 years with no predisposing comorbidities, the relative risk of heart failure or death was markedly higher for myocarditis associated with covid-19 disease than for myocarditis associated with vaccination (relative risk 5.78, 1.84 to 18.20). Conclusions Compared with myocarditis associated with covid-19 disease and conventional myocarditis, myocarditis after vaccination with SARS-CoV-2 mRNA vaccines was associated with better clinical outcomes within 90 days of admission to hospital.

All-cause mortality among Danish nursing home residents before and during the COVID-19 pandemic: a nationwide cohort study.

A substantial part of mortality during the COVID-19-pandemic occurred among nursing home residents which caused alarm in many countries. We investigate nursing home mortality in relation to the expected mortality prior to the pandemic. This nationwide register-based study included all 135,501 Danish nursing home residents between 2015 until October 6, 2021. All-cause mortality rates were calculated using a standardization method on sex and age distribution of 2020. Survival probability and lifetime lost for 180 days was calculated using Kaplan Meier estimates. Of 3,587 COVID-19 related deaths, 1137 (32%) occurred among nursing home residents. The yearly all-cause mortality rates per 100,000 person-years in 2015, 2016, and 2017 were 35,301 (95% CI: 34,671-35,943), 34,801 (95% CI: 34,180-35,432), and 35,708 (95% CI: 35,085-36,343), respectively. Slightly elevated mortality rates per 100,000 person-years were seen in 2018, 2019, 2020, and 2021 of 38,268 (95% CI: 37,620-38,929), 36,956 (95% CI: 36,323-37,600), 37,475 (95% CI: 36,838-38,122), and 38,536 (95% CI: 37,798-39,287), respectively. For SARS-CoV-2-infected nursing home residents, lifetime lost difference was 42 days (95% CI: 38-46) in 2020 versus non-infected in 2018. Among vaccinated in 2021, lifetime lost difference was 25 days (95% CI: 18-32) for SARS-CoV-2-infected versus non-infected. Even though a high proportion of COVID-19 fatalities took place in nursing homes and SARS-CoV-2-infection increased the risk of individual death, the annual mortality was only slightly elevated. For future epidemics or pandemics reporting numbers of fatal cases in relation to expected mortality is critical.

Feasibility of randomizing Danish citizens aged 65-79 years to high-dose quadrivalent influenza vaccine vs. standard-dose quadrivalent influenza vaccine in a pragmatic registry-based setting: rationale and design of the DANFLU-1 Trial.

BACKGROUND: High-dose influenza vaccines provide better protection against influenza infection than standard-dose in persons aged 65 years and above; however, in most countries, high-dose vaccines are not widely implemented. Assessing the relative effectiveness of high-dose compared to standard-dose vaccines on hospitalizations and mortality would enable more robust public health and cost-effectiveness estimates. This study aims to investigate the feasibility of conducting a pragmatic randomized clinical trial in Denmark comparing high-dose to standard-dose vaccines utilizing existing vaccination infrastructure and the Danish nationwide health registries for data collection. METHODS: The DANFLU-1 trial (NCT05048589) is a pragmatic, open-label, active-controlled randomized trial randomizing Danish citizens aged 65-79 years to either high-dose quadrivalent influenza vaccine or standard-dose quadrivalent influenza vaccine. The study utilizes the infrastructure of a private vaccination provider (Danske Lægers Vaccinations Service) for recruitment, inclusion, randomization, and vaccination. All collection of baseline and follow-up data including safety monitoring is performed centrally by the Department of Cardiology at Herlev and Gentofte Hospital, Copenhagen, Denmark using the Danish nationwide health registries. The study aims to include 40,000 participants during the 2021/2022 influenza season. The primary endpoints address feasibility and include the number of participants enrolled, randomization balance, and representativeness compared to the Danish general population. Relative vaccine effectiveness will also be assessed, however, this feasibility study is not powered for clinical outcomes and may be affected by the COVID-19 pandemic. DISCUSSION: The DANFLU-1 study is investigating the feasibility of conducting a large-scale pragmatic clinical trial in Denmark utilizing existing infrastructure and the Danish nationwide registries. This will provide valuable insight, especially for potential future fully powered vaccine trials, but also for trials wishing to investigate other interventions. TRIAL REGISTRATION: Clinicaltrials.gov : NCT05048589 , registered September 17, 2021.

Feasibility of randomizing Danish citizens aged 65–79 years to high-dose quadrivalent influenza vaccine vs. standard-dose quadrivalent influenza vaccine in a pragmatic registry-based setting: rationale and design of the DANFLU-1 Trial

Background High-dose influenza vaccines provide better protection against influenza infection than standard-dose in persons aged 65 years and above;however, in most countries, high-dose vaccines are not widely implemented. Assessing the relative effectiveness of high-dose compared to standard-dose vaccines on hospitalizations and mortality would enable more robust public health and cost-effectiveness estimates. This study aims to investigate the feasibility of conducting a pragmatic randomized clinical trial in Denmark comparing high-dose to standard-dose vaccines utilizing existing vaccination infrastructure and the Danish nationwide health registries for data collection. Methods The DANFLU-1 trial (NCT05048589) is a pragmatic, open-label, active-controlled randomized trial randomizing Danish citizens aged 65–79 years to either high-dose quadrivalent influenza vaccine or standard-dose quadrivalent influenza vaccine. The study utilizes the infrastructure of a private vaccination provider (Danske Lægers Vaccinations Service) for recruitment, inclusion, randomization, and vaccination. All collection of baseline and follow-up data including safety monitoring is performed centrally by the Department of Cardiology at Herlev and Gentofte Hospital, Copenhagen, Denmark using the Danish nationwide health registries. The study aims to include 40,000 participants during the 2021/2022 influenza season. The primary endpoints address feasibility and include the number of participants enrolled, randomization balance, and representativeness compared to the Danish general population. Relative vaccine effectiveness will also be assessed, however, this feasibility study is not powered for clinical outcomes and may be affected by the COVID-19 pandemic. Discussion The DANFLU-1 study is investigating the feasibility of conducting a large-scale pragmatic clinical trial in Denmark utilizing existing infrastructure and the Danish nationwide registries. This will provide valuable insight, especially for potential future fully powered vaccine trials, but also for trials wishing to investigate other interventions. Trial registration Clinicaltrials.gov: NCT05048589, registered September 17, 2021.

Prognostic implications of serial high-sensitivity cardiac troponin testing among patients with COVID-19: A Danish nationwide registry-based cohort study.

Background: Although troponin elevation is associated with worse outcomes among patients with coronavirus disease 2019 (COVID-19), prognostic implications of serial troponin testing are lacking. We investigated the association between serial troponin measurements and adverse COVID-19 outcomes. Methods: Using Danish registries, we identified COVID-19 patients with a high-sensitivity troponin measurement followed by a second measurement within 1-24 h. All measurements during follow-up were also utilized in subsequent time-varying analyses. We assessed all-cause mortality associated with the absence/presence of myocardial injury (≥1 troponin measurement >99th percentile upper reference limit) and absence/presence of dynamic troponin changes (>20% relative change if first measurement elevated, >50% relative change if first measurement normal). Results: Of 346 included COVID-19 patients, 56% had myocardial injury. Overall, 20% had dynamic troponin changes. In multivariable Cox regression models, myocardial injury was associated with all-cause mortality (HR = 2.56, 95%CI = 1.46-4.51), as were dynamic troponin changes (HR = 1.66, 95%CI = 1.04-2.64). We observed a low incidence of myocardial infarction (4%) and invasive coronary procedures (4%) among patients with myocardial injury. Conclusions: Myocardial injury and dynamic troponin changes determined using serial high-sensitivity troponin testing were associated with poor prognosis among patients with COVID-19. The risk of developing myocardial infarction requiring invasive management during COVID-19 hospitalization was low.

Household Exposure to Severe Acute Respiratory Syndrome Coronavirus 2 and Association With Coronavirus Disease 2019 Severity: A Danish Nationwide Cohort Study.

BACKGROUND: Households are high-risk settings for the transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Severity of coronavirus disease 2019 (COVID-19) is likely associated with the infectious dose of SARS-CoV-2 exposure. We therefore aimed to assess the association between SARS-CoV-2 exposure within households and COVID-19 severity. METHODS: We performed a Danish, nationwide, register-based, cohort study including laboratory-confirmed SARS-CoV-2-infected individuals from 22 February 2020 to 6 October 2020. Household exposure to SARS-CoV-2 was defined as having 1 individual test positive for SARS-CoV-2 within the household. Cox proportional hazards models were used to estimate the association between "critical COVID-19" within and between households with and without secondary cases. RESULTS: From 15 063 multiperson households, 19 773 SARS-CoV-2-positive individuals were included; 11 632 were categorized as index cases without any secondary household cases; 3431 as index cases with secondary cases, that is, 22.8% of multiperson households; and 4710 as secondary cases. Critical COVID-19 occurred in 2.9% of index cases living with no secondary cases, 4.9% of index cases with secondary cases, and 1.3% of secondary cases. The adjusted hazard ratio for critical COVID-19 among index cases vs secondary cases within the same household was 2.50 (95% confidence interval [CI], 1.88-3.34), 2.27 (95% CI, 1.77-2.93) for index cases in households with no secondary cases vs secondary cases, and 1.1 (95% CI, .93-1.30) for index cases with secondary cases vs index cases without secondary cases. CONCLUSIONS: We found no increased hazard ratio of critical COVID-19 among household members of infected SARS-CoV-2 index cases.

SARS-CoV-2 vaccination and myocarditis or myopericarditis: population based cohort study.

OBJECTIVE: To investigate the association between SARS-CoV-2 vaccination and myocarditis or myopericarditis. DESIGN: Population based cohort study. SETTING: Denmark. PARTICIPANTS: 4 931 775 individuals aged 12 years or older, followed from 1 October 2020 to 5 October 2021. MAIN OUTCOME MEASURES: The primary outcome, myocarditis or myopericarditis, was defined as a combination of a hospital diagnosis of myocarditis or pericarditis, increased troponin levels, and a hospital stay lasting more than 24 hours. Follow-up time before vaccination was compared with follow-up time 0-28 days from the day of vaccination for both first and second doses, using Cox proportional hazards regression with age as an underlying timescale to estimate hazard ratios adjusted for sex, comorbidities, and other potential confounders. RESULTS: During follow-up, 269 participants developed myocarditis or myopericarditis, of whom 108 (40%) were 12-39 years old and 196 (73%) were male. Of 3 482 295 individuals vaccinated with BNT162b2 (Pfizer-BioNTech), 48 developed myocarditis or myopericarditis within 28 days from the vaccination date compared with unvaccinated individuals (adjusted hazard ratio 1.34 (95% confidence interval 0.90 to 2.00); absolute rate 1.4 per 100 000 vaccinated individuals within 28 days of vaccination (95% confidence interval 1.0 to 1.8)). Adjusted hazard ratios among female participants only and male participants only were 3.73 (1.82 to 7.65) and 0.82 (0.50 to 1.34), respectively, with corresponding absolute rates of 1.3 (0.8 to 1.9) and 1.5 (1.0 to 2.2) per 100 000 vaccinated individuals within 28 days of vaccination, respectively. The adjusted hazard ratio among 12-39 year olds was 1.48 (0.74 to 2.98) and the absolute rate was 1.6 (1.0 to 2.6) per 100 000 vaccinated individuals within 28 days of vaccination. Among 498 814 individuals vaccinated with mRNA-1273 (Moderna), 21 developed myocarditis or myopericarditis within 28 days from vaccination date (adjusted hazard ratio 3.92 (2.30 to 6.68); absolute rate 4.2 per 100 000 vaccinated individuals within 28 days of vaccination (2.6 to 6.4)). Adjusted hazard ratios among women only and men only were 6.33 (2.11 to 18.96) and 3.22 (1.75 to 5.93), respectively, with corresponding absolute rates of 2.0 (0.7 to 4.8) and 6.3 (3.6 to 10.2) per 100 000 vaccinated individuals within 28 days of vaccination, respectively. The adjusted hazard ratio among 12-39 year olds was 5.24 (2.47 to 11.12) and the absolute rate was 5.7 (3.3 to 9.3) per 100 000 vaccinated individuals within 28 days of vaccination. CONCLUSIONS: Vaccination with mRNA-1273 was associated with a significantly increased risk of myocarditis or myopericarditis in the Danish population, primarily driven by an increased risk among individuals aged 12-39 years, while BNT162b2 vaccination was only associated with a significantly increased risk among women. However, the absolute rate of myocarditis or myopericarditis after SARS-CoV-2 mRNA vaccination was low, even in younger age groups. The benefits of SARS-CoV-2 mRNA vaccination should be taken into account when interpreting these findings. Larger multinational studies are needed to further investigate the risks of myocarditis or myopericarditis after vaccination within smaller subgroups.

Glycated haemoglobin levels among 3295 hospitalized COVID-19 patients, with and without diabetes, and risk of severe infection, admission to an intensive care unit and all-cause mortality.

AIM: To determine the risk of adverse outcomes across the spectrum of glycated haemoglobin (HbA1c) levels among hospitalized COVID-19 patients with and without diabetes. MATERIALS AND METHODS: Danish nationwide registries were used to study the association between HbA1c levels and 30-day risk of all-cause mortality and the composite of severe COVID-19 infection, intensive care unit (ICU) admission and all-cause mortality. The study population comprised patients hospitalized with COVID-19 (3 March 2020 to 31 December 2020) with a positive polymerase chain reaction (PCR) test and an available HbA1c ≤ 6 months before the first positive PCR test. All patients had at least 30 days of follow-up. Among patients with diabetes, HbA1c was categorized as <48 mmol/mol, 48 to 53 mmol/mol, 54 to 58 mmol/mol, 59 to 64 mmol/mol (reference) and >64 mmol/mol. Among patients without diabetes, HbA1c was stratified into <31 mmol/mol, 31 to 36 mmol/mol (reference), 37 to 41 mmol/mol and 42 to 47 mmol/mol. Thirty-day standardized absolute risks and standardized absolute risk differences are reported. RESULTS: We identified 3295 hospitalized COVID-19 patients with an available HbA1c (56.2% male, median age 73.9 years), of whom 35.8% had diabetes. The median HbA1c was 54 and 37 mmol/mol among patients with and without diabetes, respectively. Among patients with diabetes, the standardized absolute risk difference of the composite outcome was higher with HbA1c < 48 mmol/mol (12.0% [95% confidence interval {CI} 3.3% to 20.8%]) and HbA1c > 64 mmol/mol (15.1% [95% CI 6.2% to 24.0%]), compared with HbA1c 59 to 64 mmol/mol (reference). Among patients without diabetes, the standardized absolute risk difference of the composite outcome was greater with HbA1c < 31 mmol/mol (8.5% [95% CI 0.5% to 16.5%]) and HbA1c 42 to 47 mmol/mol (6.7% [95% CI 1.3% to 12.1%]), compared with HbA1c 31 to 36 mmol/mol (reference). CONCLUSIONS: Patients with COVID-19 and HbA1c < 48 mmol/mol or HbA1c > 64 mmol/mol had a higher associated risk of the composite outcome. Similarly, among patients without diabetes, varying HbA1c levels were associated with higher risk of the composite outcome.

Protective potential of high-intensity interval training on cardiac structure and function after COVID-19: protocol and statistical analysis plan for an investigator-blinded randomised controlled trial.

INTRODUCTION: COVID-19 is associated with a marked systemic inflammatory response with concomitant cardiac injury and remodelling, but it is currently unknown whether the latter is reversible. Given that high-intensity interval training (HIIT) is a powerful stimulus to improve cardiorespiratory fitness while also eliciting marked anti-inflammatory effects, it may be an important countermeasure of reducing cardiopulmonary morbidity following COVID-19. METHODS AND ANALYSIS: 40 COVID-19 survivors who have been discharged from hospital will be included in this investigator-blinded randomised study with a 12-week HIIT intervention. Patients will be 1:1 block-randomised by sex to either a supervised HIIT exercise group or standard care (control group). The main hypothesis is that a 12-week HIIT scheme is a safe way to improve loss of cardiac mass and associated cardiorespiratory fitness, despite hypothesised limited HIIT-induced changes in conventional lung function indices per se. Ultimately, we hypothesise that the HIIT scheme will reduce post-COVID-19 symptoms and improve quality of life. ETHICS AND DISSEMINATION: This study is approved by the Scientific Ethical Committee at the Capital Region of Denmark (H-20033733, including amendments 75068 and 75799) and registered at ClinicalTrials.gov (NCT04647734, pre-results). The findings will be published in a peer-reviewed journal, including cases of positive, negative and inconclusive results.Trial registration number NCT04549337.

Angiotensin Receptor-Neprilysin Inhibition in Acute Myocardial Infarction.

BACKGROUND: In patients with symptomatic heart failure, sacubitril-valsartan has been found to reduce the risk of hospitalization and death from cardiovascular causes more effectively than an angiotensin-converting-enzyme inhibitor. Trials comparing the effects of these drugs in patients with acute myocardial infarction have been lacking. METHODS: We randomly assigned patients with myocardial infarction complicated by a reduced left ventricular ejection fraction, pulmonary congestion, or both to receive either sacubitril-valsartan (97 mg of sacubitril and 103 mg of valsartan twice daily) or ramipril (5 mg twice daily) in addition to recommended therapy. The primary outcome was death from cardiovascular causes or incident heart failure (outpatient symptomatic heart failure or heart failure leading to hospitalization), whichever occurred first. RESULTS: A total of 5661 patients underwent randomization; 2830 were assigned to receive sacubitril-valsartan and 2831 to receive ramipril. Over a median of 22 months, a primary-outcome event occurred in 338 patients (11.9%) in the sacubitril-valsartan group and in 373 patients (13.2%) in the ramipril group (hazard ratio, 0.90; 95% confidence interval [CI], 0.78 to 1.04; P = 0.17). Death from cardiovascular causes or hospitalization for heart failure occurred in 308 patients (10.9%) in the sacubitril-valsartan group and in 335 patients (11.8%) in the ramipril group (hazard ratio, 0.91; 95% CI, 0.78 to 1.07); death from cardiovascular causes in 168 (5.9%) and 191 (6.7%), respectively (hazard ratio, 0.87; 95% CI, 0.71 to 1.08); and death from any cause in 213 (7.5%) and 242 (8.5%), respectively (hazard ratio, 0.88; 95% CI, 0.73 to 1.05). Treatment was discontinued because of an adverse event in 357 patients (12.6%) in the sacubitril-valsartan group and 379 patients (13.4%) in the ramipril group. CONCLUSIONS: Sacubitril-valsartan was not associated with a significantly lower incidence of death from cardiovascular causes or incident heart failure than ramipril among patients with acute myocardial infarction. (Funded by Novartis; PARADISE-MI ClinicalTrials.gov number, NCT02924727.).

Nationwide cardiovascular disease admission rates during a second COVID-19 lockdown.

Societal lockdowns during the first wave of the coronavirus disease 2019 pandemic were associated with decreased admission rates for acute cardiovascular conditions worldwide. In this nationwide Danish study of the first five weeks of a second pandemic lockdown, incidence of new-onset heart failure and atrial fibrillation remained stable, but there was a significant drop in new-onset ischemic heart disease and ischemic stroke during the fourth week of lockdown, which normalized promptly. The observed drops were lower compared to the first Danish lockdown in March 2020; thus, our data suggest that declines in acute cardiovascular disease admission rates during future lockdowns are avoidable.

Work exposure and associated risk of hospitalisation with pneumonia and influenza: A nationwide study.

BACKGROUND: Pneumonia and influenza are major health concerns and constitute a high economic burden. However, few data are available on the associated risk of pneumonia and influenza and work exposure on a large population scale. AIM: This study aimed to examine the associated risk of pneumonia and influenza by type of work exposure. METHODS: By cross-linking administrative Danish registries, we classified people in 10 different profession types. The main outcome was hospitalisation with pneumonia or influenza. A multivariable Poisson regression analysis was used to assess the associated incidence rate ratio (IRR) of being hospitalised with pneumonia or influenza by type of profession. RESULTS: A total of 1,327,606 people added risk time to the analyses. In a multivariable model, work in day care, public transportation, sewers and nursing home care was associated with an increased risk of hospitalisation with pneumonia compared to work within public administration: IRR=1.20 (95% confidence interval (CI) 1.12-1.28), IRR=1.21 (95% CI 1.09-1.34), IRR=1.61 (95% CI 1.19-2.19) and IRR=1.10 (95% CI 1.03-1.18), respectively. In a multivariable analysis, people working within public transportation were associated with an increased risk of hospitalisation with influenza compared to people working within public administration: IRR=2.54 (95% CI 1.79-3.58). CONCLUSIONS: Working in day care, public transportation, sewers and nursing home care increased the associated risk of hospitalisation with pneumonia, and working within public transportation increased the associated risk of being hospitalised with influenza compared to working within public administration.

Severe mental illness is associated with increased mortality and severe course of COVID-19.

OBJECTIVE: Psychiatric disorders have been associated with unfavourable outcome following respiratory infections. Whether this also applies to coronavirus disease 2019 (COVID-19) has been scarcely investigated. METHODS: Using the Danish administrative databases, we identified all patients with a positive real-time reverse transcription-polymerase chain reaction test for COVID-19 in Denmark up to and including 2 January 2021. Multivariable cox regression was used to calculate 30-day absolute risk and average risk ratio (ARR) for the composite end point of death from any cause and severe COVID-19 associated with psychiatric disorders, defined using both hospital diagnoses and redemption of psychotropic drugs. RESULTS: We included 144,321 patients with COVID-19. Compared with patients without psychiatric disorders, the standardized ARR of the composite outcome was significantly increased for patients with severe mental illness including schizophrenia spectrum disorders 2.43 (95% confidence interval [CI], 1.79-3.07), bipolar disorder 2.11 (95% CI, 1.25-2.97), unipolar depression 1.70 (95% CI, 1.38-2.02), and for patients who redeemed psychotropic drugs 1.70 (95% CI, 1.48-1.92). No association was found for patients with other psychiatric disorders 1.13 (95% CI, 0.86-1.38). Similar results were seen with the outcomes of death or severe COVID-19. Among the different psychiatric subgroups, patients with schizophrenia spectrum disorders had the highest 30-day absolute risk for the composite outcome 3.1% (95% CI, 2.3-3.9%), death 1.2% (95% CI, 0.4-2.0%) and severe COVID-19 2.7% (95% CI, 1.9-3.6%). CONCLUSION: Schizophrenia spectrum disorders, bipolar disorder, unipolar depression and psychotropic drug redemption are associated with unfavourable outcomes in patients with COVID-19.

The association between cardiovascular disease admission rates and the coronavirus disease 2019 lockdown and reopening of a nation: a Danish nationwide cohort study.

AIMS: To investigate the admission rates of cardiovascular diseases, overall and according to subgroups, and subsequent mortality rates during the coronavirus disease 2019 societal lockdown (12 March 2020) and reopening phase (15 April 2020) in Denmark. METHODS AND RESULTS: Using Danish nationwide registries, we identified patients with a first-time acute cardiovascular admission in two periods: (i) 2 January-16 October 2019 and (ii) 2 January-15 October 2020. Weekly incidence rates of a first-time cardiovascular admission, overall and according to subtypes, in the two periods were calculated. The incidence rate of first-time cardiovascular admissions overall was significantly lower during the first weeks of lockdown in 2020 compared with a similar period in 2019 but increased after the gradual reopening of the Danish society. A similar trend was observed for all subgroups of cardiovascular diseases. The mortality rate among patients admitted after March 12 was not significantly different in 2020 compared with 2019 [mortality rate ratio 0.98; 95% confidence interval (CI) 0.91-1.06)]. CONCLUSION: In Denmark, we observed a substantial decrease in the rate of acute cardiovascular admissions, overall and according to subtypes, during the first weeks of lockdown. However, after the gradual reopening of the Danish society, the admission rates for acute cardiovascular diseases increased and returned to rates similar to those observed in 2019. The mortality rate in patients admitted with cardiovascular diseases during lockdown was similar to that of patients during the same period in 2019.