Characterising Long Covid: a living systematic review update with controlled studies (preprint)

Background: The clinical sequelae (Long Covid) of acute Covid-19 are recognised globally, yet the risk of developing them is unknown. Methods: A living systematic review (second version). Bibliographical records from the C19 Living Map Long Covid segment (22nd February 2022), Medline, CINAHL, Global Health, WHO Covid-19 database, LitCOVID, and Google Scholar (18th November 2021). We included studies with at least 100 people at 12 weeks or more post-Covid-19 onset and with a control group without confirmed Covid-19. Risk of bias was assessed using the Newcastle-Ottawa scale. Symptoms are aligned with the Post Covid-19 Condition Core Outcome Set. We present descriptive statistics and use meta-analysis to estimate the relative risk of experiencing Long Covid. Results Twenty-eight studies were included: 20 cohort, five case-controls, three cross-sectional. Studies reported on 242,715 people with Covid-19 (55.6% female) and 276,317 controls (55.7% female) in 16 countries. Most were of moderate quality (71%). Only two were set in low-middle-income countries and few included children (18%). The longest mean follow-up time was 419.8 (standard deviation 49.4) days post-diagnosis. The relative risk (RR) of experiencing persistent or new symptoms in cases compared with controls was 1.53 (95% CI: 1.50 to 1.56). The core outcomes with the highest increased risk were cardiovascular (RR 2.53 95% CI: 2.16 to 2.96), cognitive (RR 1.99; 95% CI: 1.82 to 2.17), and physical functioning (RR 1.85; 95% CI: 1.75 to 1.96). Conclusion: SARS-CoV-2 infection is associated with a higher risk of new or persistent symptoms when compared with controls that can last over a year following acute Covid-19. There is still a lack of robust studies set in lower resourced settings and current studies have high heterogeneity and potential misclassifications of cases and controls. Future research should explore the role of vaccination and different variants on the risk of developing Long Covid.

From SARS and MERS to COVID-19: a review of the quality and responsiveness of clinical management guidelines in outbreak settings (preprint)

ObjectiveTo assess the responsiveness and quality of clinical management guidelines (CMGs) in SARS, MERS and COVID-19 and determine whether this has improved over time. DesignRapid literature review, quality assessment and focus group consultation. Data Sources- Google and Google Scholar were systematically searched from inception to 6th June 2020.This was supplemented with hand searches of national and international public health agency and infectious disease society websites as well as directly approaching clinical networks in regions where few CMGs had been identified via the primary search. Eligibility CriteriaCMGs for the treatment of COVID-19/SARS/MERS providing recommendations on supportive care and/or specific treatment. MethodsData extraction was performed using a standardised form. The Appraisal of Guidelines for Research and Evaluation (AGREE-II) tool was used to evaluate the quality of the CMGs. Six COVID-19 treatments were selected to assess the responsiveness of a subset of guidelines and their updates to 20th November 2020. We ran two sessions of focus groups with patient advocates to elicit their views on guideline development. ResultsWe included 37 COVID-19, six SARS, and four MERS CMGs. Evidence appraisals in CMGs generally focused on novel drugs rather than basic supportive care; where evidence for the latter was provided it was generally of a low quality. Most CMGs had major methodological flaws (only two MERS-CoV and four COVID-19 CMGs were recommended for use by both reviewers without modification) and there was no evidence of improvement in quality over time. CMGs scored lowest in the following AGREE-II domains: scope and purpose, editorial independence, stakeholder engagement, and rigour of development. Of the COVID-19 CMGs, only eight included specific guidance for the management of elderly patients and only ten for high-risk groups; a further eight did not specify the target patient group at all. Early in the pandemic, multiple guidelines recommended unproven treatments and whilst in general findings of major clinical trials were eventually adopted, this was not universally the case. Eight guidelines recommended that use of unproven agents should be considered on a case-by-case basis. Patient representatives expressed concern about the lack of engagement with them in CMG development and that these documents are not accessible to non-experts. ConclusionThe quality of most CMGs produced in coronaviridae outbreaks is poor and we have found no evidence of improvement over time, highlighting that current development frameworks must be improved. There is an need to strengthen the evidence base surrounding basic supportive care and develop methods to engage patients in CMG development from the beginning in outbreak settings. Systematic review registrationPROSPERO CRD42020167361