The life and death of living systematic reviews: a methodological survey.

OBJECTIVES: The objectives of this study are to describe the characteristics of living systematic reviews (LSRs) and to understand their life cycles. STUDY DESIGN AND SETTING: We conducted a comprehensive search up to April 2021 then selected articles and abstracted data in duplicate and independently. We undertook descriptive analyses and calculated delay in version update and delay since the last published version. RESULTS: We included 76 eligible LSRs with a total of 279 eligible versions. The majority of LSRs was from the clinical field (70%), was COVID-19 related (63%), and had a funding source specified (62%). The median number of versions per LSR was 2 (interquartile range (IQR) 1-4; range 1-19). The median and IQR for the ratio of the actual period of update to the planned period of update was 1.12 (0.81; 1.71). Out of all reviews with a 'planned period of update' and at least one update (N = 19), eight LSRs (42%) had a period since last published version greater than 3 times the planned period of update. No LSR included a 'retirement notice' in their latest published version. CONCLUSION: While most LSR complied with the planned period of producing updates, a substantive proportion lagged since their last update.

Ventilation Techniques and Risk for Transmission of Coronavirus Disease, Including COVID-19: A Living Systematic Review of Multiple Streams of Evidence.

BACKGROUND: Mechanical ventilation is used to treat respiratory failure in coronavirus disease 2019 (COVID-19). PURPOSE: To review multiple streams of evidence regarding the benefits and harms of ventilation techniques for coronavirus infections, including that causing COVID-19. DATA SOURCES: 21 standard, World Health Organization-specific and COVID-19-specific databases, without language restrictions, until 1 May 2020. STUDY SELECTION: Studies of any design and language comparing different oxygenation approaches in patients with coronavirus infections, including severe acute respiratory syndrome (SARS) or Middle East respiratory syndrome (MERS), or with hypoxemic respiratory failure. Animal, mechanistic, laboratory, and preclinical evidence was gathered regarding aerosol dispersion of coronavirus. Studies evaluating risk for virus transmission to health care workers from aerosol-generating procedures (AGPs) were included. DATA EXTRACTION: Independent and duplicate screening, data abstraction, and risk-of-bias assessment (GRADE for certainty of evidence and AMSTAR 2 for included systematic reviews). DATA SYNTHESIS: 123 studies were eligible (45 on COVID-19, 70 on SARS, 8 on MERS), but only 5 studies (1 on COVID-19, 3 on SARS, 1 on MERS) adjusted for important confounders. A study in hospitalized patients with COVID-19 reported slightly higher mortality with noninvasive ventilation (NIV) than with invasive mechanical ventilation (IMV), but 2 opposing studies, 1 in patients with MERS and 1 in patients with SARS, suggest a reduction in mortality with NIV (very-low-certainty evidence). Two studies in patients with SARS report a reduction in mortality with NIV compared with no mechanical ventilation (low-certainty evidence). Two systematic reviews suggest a large reduction in mortality with NIV compared with conventional oxygen therapy. Other included studies suggest increased odds of transmission from AGPs. LIMITATION: Direct studies in COVID-19 are limited and poorly reported. CONCLUSION: Indirect and low-certainty evidence suggests that use of NIV, similar to IMV, probably reduces mortality but may increase the risk for transmission of COVID-19 to health care workers. PRIMARY FUNDING SOURCE: World Health Organization. (PROSPERO: CRD42020178187).

Adverse effects of remdesivir, hydroxychloroquine and lopinavir/ritonavir when used for COVID-19: systematic review and meta-analysis of randomised trials.

BACKGROUND: To summarise specific adverse effects of remdesivir, hydroxychloroquine and lopinavir/ritonavir in patients with COVID-19. METHODS: We searched 32 databases through 27 October 2020. We included randomised trials comparing any of the drugs of interest to placebo or standard care, or against each other. We conducted fixed-effects pairwise meta-analysis and assessed the certainty of evidence using the grading of recommendations assessment, development and evaluation approach. RESULTS: We included 16 randomised trials which enrolled 8152 patients. For most interventions and outcomes the certainty of the evidence was very low to low except for gastrointestinal adverse effects from hydroxychloroquine, which was moderate certainty. Compared with standard care or placebo, low certainty evidence suggests that remdesivir may not have an important effect on acute kidney injury (risk difference (RD) 8 fewer per 1000, 95% CI 27 fewer to 21 more) or cognitive dysfunction/delirium (RD 3 more per 1000, 95% CI 12 fewer to 19 more). Low certainty evidence suggests that hydroxychloroquine may increase the risk of cardiac toxicity (RD 10 more per 1000, 95% CI 0 more to 30 more) and cognitive dysfunction/delirium (RD 33 more per 1000, 95% CI 18 fewer to 84 more), whereas moderate certainty evidence suggests hydroxychloroquine probably increases the risk of diarrhoea (RD 106 more per 1000, 95% CI 48 more to 175 more) and nausea and/or vomiting (RD 62 more per 1000, 95% CI 23 more to 110 more) compared with standard care or placebo. Low certainty evidence suggests lopinavir/ritonavir may increase the risk of diarrhoea (RD 168 more per 1000, 95% CI 58 more to 330 more) and nausea and/or vomiting (RD 160 more per 1000, 95% CI 100 more to 210 more) compared with standard care or placebo. DISCUSSION: Hydroxychloroquine probably increases the risk of diarrhoea and nausea and/or vomiting and may increase the risk of cardiac toxicity and cognitive dysfunction/delirium. Lopinavir/ritonavir may increase the risk of diarrhoea and nausea and/or vomiting. Remdesivir may have no important effect on risk of acute kidney injury or cognitive dysfunction/delirium. These findings provide important information to support the development of evidence-based management strategies for patients with COVID-19.

COVID-19 transmission during swimming-related activities: a rapid systematic review.

BACKGROUND: There are uncertainties about mitigating strategies for swimming-related activities in the context of the COVID-19 pandemic. There is an opportunity to learn from the experience of previous re-openings to better plan the future one. Our objectives are to systematically review the evidence on (1) the association between engaging in swimming-related activities and COVID-19 transmission; and (2) the effects of strategies for preventing COVID-19 transmission during swimming-related activities. METHODS: We conducted a rapid systematic review. We searched in the L·OVE (Living OVerview of Evidence) platform for COVID-19. The searches covered the period from the inception date of each database until April 19, 2021. We included non-randomized studies for the review on association of COVID-19 transmission and swimming-related activities. We included guidance documents reporting on the strategies for prevention of COVID-19 transmission during swimming-related activities. We also included studies on the efficacy and safety of the strategies. Teams of two reviewers independently assessed article eligibility. For the guidance documents, a single reviewer assessed the eligibility and a second reviewer verified the judgement. Teams of two reviewers extracted data independently. We summarized the findings of included studies narratively. We synthesized information from guidance documents according to the identified topics and subtopics, and presented them in tabular and narrative formats. RESULTS: We identified three studies providing very low certainty evidence for the association between engaging in swimming-related activities and COVID-19 transmission. The analysis of 50 eligible guidance documents identified 11 topics: ensuring social distancing, ensuring personal hygiene, using personal protective equipment, eating and drinking, maintaining the pool, managing frequently touched surfaces, ventilation of indoor spaces, screening and management of sickness, delivering first aid, raising awareness, and vaccination. One study assessing the efficacy of strategies to prevent COVID-19 transmission did not find an association between compliance with precautionary restrictions and COVID-19 transmission. CONCLUSIONS: There are major gaps in the research evidence of relevance to swimming-related activities in the context of the COVID-19 pandemic. However, the synthesis of the identified strategies from guidance documents can inform public health management strategies for swimming-related activities, particularly in future re-opening plans.