Characterising long-term covid-19: a rapid living systematic review (preprint)

ObjectiveTo understand the frequency, profile, and duration of persistent symptoms of covid-19 and to update this understanding as new evidence emerges. DesignA living systematic review produced in response to the rapidly evolving evidence base for long covid. Data sourcesMedline and CINAHL (EBSCO), Global Health (Ovid), WHO Global Research Database on covid-19, LitCOVID, and Google Scholar to 28th September 2020. Study selectionStudies reporting long-term symptoms and complications among people with confirmed or suspected covid-19, both in those previously hospitalised and those never hospitalised. Only studies incorporating over 100 participants qualified for data extraction and were assessed for risk of bias. Results were analysed using descriptive statistics. Quality assessmentRisk of bias was assessed using a quality assessment checklist for prevalence studies. ResultsTwenty-eight studies qualified for data extraction; 16 of these were cohort studies, ten cross-sectional, and two large case series. The analysis included 9,442 adults with covid-19 from 13 countries. The longest mean follow-up period was 111 (SD: 11) days post-hospital discharge. A wide range of systemic, cardiopulmonary, gastrointestinal, neurological, and psychosocial symptoms was reported, of which the most common were breathlessness, fatigue, smell and taste disturbance, and anxiety. Persistent symptoms were described across both previously hospitalised and non-hospitalised populations. The quality of evidence was low, with a high risk of bias and heterogeneity in prevalence. The incorporated studies demonstrated limited external validity, a lack of control subjects, and inconsistent data collection methods. Few studies were conducted in primary care, no studies focused solely on children, and no studies were set in low- and middle-income countries. ConclusionOur findings suggest that long covid is a complex, heterogeneous condition; however, the limited evidence base currently precludes a precise definition of its symptoms and prevalence. There is a clear need for robust, controlled, prospective cohort studies, including different at-risk populations and settings, incorporating appropriate investigations, collected and recorded in a standardised way. Systematic review registrationThe protocol was prospectively registered on the PROSPERO database (CRD42020211131). Readers noteThis living systematic review will be updated regularly as new evidence emerges. The search terms and inclusion criteria will be updated in line with new evidence, research priorities and policy needs. This version is the original publication. Updates may occur for up to two years from the date of original publication. When citing this paper please consider adding the version number and date of access for clarity. O_TEXTBOXSection 1: What is already known on this topic? O_LIA significant number of people continue to describe symptoms long after the acute phase of covid-19 is over, so called long covid. C_LIO_LIThere is no case definition for long covid, which appears to be a heterogeneous condition with an uncertain prevalence. C_LI Section 2: What this study adds O_LIThis living systematic review provides a comprehensive summary of the published evidence on persistent symptoms of covid-19 and will be regularly updated. C_LIO_LIThe breadth of reported symptoms suggests a complex, heterogeneous condition affecting both hospitalised patients and those managed in the community. C_LIO_LIHowever, the current evidence base of the clinical spectrum of long covid is of limited quality and is vulnerable to biases. C_LIO_LIOur review identifies those areas where further long covid research is critically needed. C_LI C_TEXTBOX

What is the recovery rate and risk of long-term consequences following a diagnosis of COVID-19? - A harmonised, global longitudinal observational study (preprint)

Introduction Very little is known about possible clinical sequelae that may persist after resolution of the acute Coronavirus Disease 2019 (COVID-19). A recent longitudinal cohort from Italy including 143 patients recovered after hospitalisation with COVID-19 reported that 87% had at least one ongoing symptom at 60 day follow-up. Early indications suggest that patients with COVID-19 may need even more psychological support than typical ICU patients. The assessment of risk factors for longer term consequences requires a longitudinal study linked to data on pre-existing conditions and care received during the acute phase of illness. Methods and analysis This is an international open-access prospective, observational multi-site study. It will enrol patients following a diagnosis of COVID-19. Tier 1 is developed for following up patients day 28 post-discharge, additionally at 3 to 6 months intervals. This module can be used to identify sub-sets of patients experiencing specific symptomatology or syndromes for further follow up. A Tier 2 module will be developed for in-clinic, in-depth follow up. The primary aim is to characterise physical consequences in patients post-COVID-19. Secondary aim includes estimating the frequency of and risk factors for post-COVID- 19 medical sequalae, psychosocial consequences and post-COVID-19 mortality. A subset of patients will have sampling to characterize longer term antibody, innate and cell-mediated immune responses to SARS-CoV-2. Ethics and dissemination This collaborative, open-access study aims to characterize the frequency of and risk factors for long-term consequences and characterise the immune response over time in patients following a diagnosis of COVID-19 and facilitate standardized and longitudinal data collection globally. The outcomes of this study will inform strategies to prevent long term consequences; inform clinical management, direct rehabilitation, and inform public health management to reduce overall morbidity and improve outcomes of COVID-19.