Knowledge is limited on how changing SARS-CoV-2 variants may translate into different characteristics and affect the prognosis of patients with long COVID, especially following Omicron variants. We compared long-term prognosis of patients in a Danish Post-COVID Clinic infected with wild-type strain, Alpha, Delta, or Omicron variants as well as the pre-Omicron compared to the Omicron period. At enrollment, a Post-COVID symptom Questionnaire (PCQ), and standard health scores, were registered and repeated four times until 1.5 years after infection. PCQ was the primary outcome to assess the severity of long COVID, and Delta PCQ to assess failure to improve. A total of 806 patients were enrolled. Patients infected with Omicron and Delta variants presented with more severe long COVID (median PCQ 43 in Delta vs 38 in wild-type, P = 0.003) and health scores (EuroQol five-dimension five-level-index was 0.70 in Omicron vs 0.76 in wild-type, P = 0.009 and 0.78 pre-Omicron, P = 0.006). At 1.5 years after infection, patients had no clinically meaningful decline in severity of long COVID, and 57% (245/429) of patients failed to improve 1.5 years after infection, with no differences between variants. More than half of patients referred to a Post-COVID Clinic failed to improve in long COVID severity 1.5 years after infection regardless of variants of SARS-CoV-2.

Vitamin D deficiency has been studied in the context of acute coronavirus disease 2019 (COVID-19), revealing associations with increased severity and mortality. Yet, the influence of vitamin D on long COVID symptoms remains unknown. The purpose of this study is to examine the effect of vitamin D on long COVID symptoms. Over the study period, 50,432 individuals within the catchment area of the outpatient COVID-19 clinic tested positive for SARS-CoV-2 via PCR, with 547 patients subsequently referred to a specialized Post-COVID Clinic, and 447 of them enrolled in the study. Patient-reported symptoms and paraclinical measures including vitamin D were evaluated in 442 patients. The majority of participants were female (72%, n = 320/442). The consumption of alcohol and number of current smokers were low. Low vitamin D was observed in 26% (n = 115/442) of the patients, most commonly in male participants (odds ratio (OR) = 1.77, 95% confidence interval (CI) (1.12, 2.79), p = 0.014). Additionally, low vitamin D was correlated with a younger mean age of 41 years (standard deviation (SD) = 12) as opposed to 48 years (SD = 13) in patients with normal vitamin D levels (OR = 0.96, 95% CI (0.94, 0.97), p < 0.001). While our study population indicated a potentially higher prevalence of vitamin D insufficiency in this population compared to the general population, no significant differences in prevalence of symptom or symptom severity scores were observed between the low and normal vitamin D groups. In patients in a Post-COVID Clinic, we found no association between vitamin D levels and long COVID symptoms.

Background: Post-COVID Clinics were recommended for patients with persistent symptoms following COVID-19, but no specific tests were suggested for evaluation. This study aimed to present a post-COVID clinic patient cohort and evaluate the use of a post-COVID symptom questionnaire (PCQ) score. Methods: Patients were referred from a population of approximately 1 million citizens. PCQ and standardized health scales were registered. Descriptive analyses were performed to assess the prevalence of symptoms, and correlation analyses was undertaken to asses convergent and discriminant trends between PCQ scores and health scales. Results: Of 547 patients, 447 accepted inclusion. The median age was 47 years and 12% of the patients were hospitalized. At a median of 6.3 (IQR 4.4–9.9) months after the onset of symptoms, 82% of the patients reported both physical exhaustion and concentration difficulties. Functional disability and extreme fatigue were reported as moderate to severe by 33% and 62% of the patients, respectively. The PCQ score correlated significantly with each of the standardized health scales. Conclusion: Patients referred to a Post-COVID Clinic were previously generally healthy. At the time of diagnosis, they reported multiple symptoms with severely affected health. The PCQ score could be used as valid measure of Post-COVID severity.

Follow-up studies of COVID-19 survivors have been performed to characterize persistence of long-term symptoms, but data are scarce on one year of follow-up. This study provides data from 48 weeks of follow-up after discharge. All patients discharged from the Department of Infectious Diseases at Aarhus University Hospital, Denmark between 1 March and 1 July 2020 were followed for 48 weeks. In total, 45 of 66 eligible patients were interviewed after 48 weeks. The median age was 57 (IQR 51–70) years, the majority were female (53%) and Caucasian (87%). Median BMI was 28.1 (IQR 24.8–32.6) kg/m². One or more comorbidities were registered among 62% of the patients. In total, 39 out of 45 (87%) interviewed patients reported persistence of at least one symptom 48 weeks after hospitalization with COVID-19. Most frequently reported symptoms were fatigue, dyspnea, and concentration difficulties. This study provides new long-term data following COVID-19, contributing to the accumulating data of COVID-19 sequelae. Many patients suffer long-term sequelae and further research is urgently needed to gain further knowledge of the duration and therapeutic options.

(1) Background: Post-arrival screening for infectious diseases is routinely offered to newly arrived refugees in Denmark, including tests for hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency virus (HIV), and syphilis. This study aimed to examine the cascade of care following positive screening results in a local cohort of refugees in Denmark, with a focus on subsequent clinical management, follow-up, and outcomes. (2) Methods: This retrospective cohort study included 1506 newly arrived refugees of all ages and countries of origin. All were offered a post-arrival infectious disease screening in Denmark. Clinical records were reviewed to assess progression through the cascade of care, including referral, evaluation, follow-up, and clinical outcomes among individuals with positive screening results. (3) Results: Of the 1506 screened refugees, 33 (2.2%) had at least one positive screening result. Among the 15 individuals with detectable hepatitis B surface antigen, six (43%) attended regular follow-up, while eight (57%) were lost during the cascade of care. Two participants screened positive for HCV antibodies; both underwent initial clinical evaluation, but their subsequent care trajectories differed due to repeated non-attendance or undocumented reasons. Only one participant with non-specific syphilis antibodies completed follow-up in accordance with national guidelines. One participant was diagnosed with HIV and successfully linked to care. (4) Conclusions: The prevalence of screened infectious diseases in this local Danish refugee cohort was low and consistent with findings from comparable settings. Although post-arrival screening facilitates the identification of infectious diseases, substantial loss to follow-up occurred after initial diagnosis, limiting the effectiveness of follow-up and treatment. These findings highlight the need for targeted, interdisciplinary strategies addressing organisational, social, and individual barriers to improve continuity of care following screening.

Background: Identifying and addressing long-term health and societal challenges after COVID-19 is a research priority. Objectives: To create an international, multidisciplinary COVID-19 database, and synthesise long-term outcomes, predictors and costs. Design: Systematic identification of COVID-19 data sets and meta-analysis of individual participant data on long-term outcomes after COVID-19. Setting: Contributed data were collected in clinical, community and research settings. Interventions: Interventions from original studies were included as covariates in models. Data sources: MEDLINE, Cochrane Central Register of Controlled Trials, EMBASE, Web of Science, PsycInfo ^® (American Psychological Association, Washington, DC, USA), Cumulative Index to Nursing and Allied Health Literature, World Health Organization Global Index Medicus, Epistemonikos, LitCOVID; World Health Organization International Clinical Trials Registry Platform; ClinicalTrials.gov and supplementary searches for studies (November 2019–November 2021) were searched for studies on > 10 people from cohort, case-control, survey or randomised controlled trial studies, across any setting, describing validated assessment instruments, symptoms, hospitalisation, discharge destination or mortality beyond 28-days after COVID-19 onset. Data were extracted by two independent reviewers. Methods: Principal investigators contributed fully anonymised individual participant data. Demography, equity and symptoms were described. Assessment instruments were mapped to the International Classification of Functioning, Disability and Health. Factors associated with outcomes at 3–6 months, 9–12 months and beyond 12 months of index infection, for n > 500 individual participant data and > 1 data set were described using ratio of difference, point estimates, odds ratio and 95% confidence interval, as appropriate. The Mixed Methods Appraisal Tool described study quality; models were appraised using a Grading of Recommendations Assessment, Development and Evaluation-informed approach; heterogeneity was described using I ² . Outcome measures: Included overall perception of health, multidomain cognitive function, anxiety, depression, stress, post-traumatic stress disorder, fatigue, strength, walking ability, mobility, coping with daily life, breathlessness, mortality, later hospitalisation and health-related quality of life. Results: PRECIOUS collated 116 data sets from 40 countries (individual participant data = 62,849), comprising 20 randomised controlled trials, 13 case-control, 60 cohort 2 longitudinal, 1 survey and 20 other study types. Participants’ median age was 58 years interquartile range (45–68); 34,185 (54.4%) were female; 158 unique symptoms and 137 unique assessment instruments were captured, predominantly describing International Classification of Function, Disability and Health-body functions. Women had poorer outcomes across 30/37 models, compared with men. In 15/37 models, pre-existing lung disease and increasing age were associated with poorer outcomes; hospitalisation, diabetes and chronic kidney disease were each associated with poorer outcomes in 8/37 models. Initial hospitalisation resulted in lower health-related quality of life that did not recover for up to 2 years after initial infection. Heterogeneity was low in 34/37 models; 22/37 models were of moderate and 11/37 were of low quality. Limitations: Use of secondary data limits available covariates, outcomes and time points to those included in primary data sets; evidence was primarily based on high-income countries. There was a lack of data on longer-term healthcare resource use to estimate the costs to the healthcare system. Conclusions: PRECIOUS contributes to the overall picture of long-term COVID-19 outcomes beyond the long-COVID condition and highlights poorer long-term outcomes in women and people with pre-existing comorbidities. Future work: Evidence gaps included healthcare resource use, isolation, loneliness, societal participation and return to work outcomes. Data are needed on the role of health inequity on long-term outcomes. Study registration: This study is registered as PROSPERO (CRD42020224323, IRAS ID: 293578). Funding: This award was funded by the National Institute for Health and Care Research (NIHR) Health and Social Care Delivery Research programme (NIHR award ref: NIHR132895) and is published in full in Health and Social Care Delivery Research ; Vol. 14, No. 29. See the NIHR Funding and Awards website for further award information.