Cochrane Db Syst Rev
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Cochrane Db Syst Rev · Oct 2020
ReviewProphylaxis of thromboembolism during therapy with asparaginase in adults with acute lymphoblastic leukaemia.
The risk of venous thromboembolism is increased in adults and enhanced by asparaginase-based chemotherapy, and venous thromboembolism introduces a secondary risk of treatment delay and premature discontinuation of key anti-leukaemic agents, potentially compromising survival. Yet, the trade-off between benefits and harms of primary thromboprophylaxis in adults with acute lymphoblastic leukaemia (ALL) treated according to asparaginase-based regimens is uncertain. OBJECTIVES: The primary objectives were to assess the benefits and harms of primary thromboprophylaxis for first-time symptomatic venous thromboembolism in adults with ALL receiving asparaginase-based therapy compared with placebo or no thromboprophylaxis. The secondary objectives were to compare the benefits and harms of different groups of primary systemic thromboprophylaxis by stratifying the main results per type of drug (heparins, vitamin K antagonists, synthetic pentasaccharides, parenteral direct thrombin inhibitors, direct oral anticoagulants, and blood-derived products for antithrombin substitution). ⋯ Randomised controlled trials (RCTs); including quasi-randomised, controlled clinical, cross-over, and cluster-randomised trial designs) comparing any parenteral/oral preemptive anticoagulant or mechanical intervention with placebo or no thromboprophylaxis, or comparing two different pre-emptive anticoagulant interventions in adults aged at least 18 years with ALL treated according to asparaginase-based chemotherapy regimens. For the description of harms, non-randomised observational studies with a control group were eligible for inclusion. DATA COLLECTION AND ANALYSIS: Using a standardised data collection form, two review authors independently screened and selected studies, extracted data, assessed risk of bias for each outcome using standardised tools (RoB 2.0 tool for RCTs and ROBINS-I tool for non-randomised studies) and the certainty of evidence for each outcome using the GRADE approach. Primary outcomes included first-time symptomatic venous thromboembolism, all-cause mortality, and major bleeding. Secondary outcomes included asymptomatic venous thromboembolism, venous thromboembolism-related mortality, adverse events (i.e. clinically relevant non-major bleeding and heparin-induced thrombocytopenia for trials using heparins), and quality of life. Analyses were performed according to the guidelines of the Cochrane Handbook for Systematic Reviews of Interventions. For non-randomised studies, we evaluated all studies (including studies judged to be at critical risk of bias in at least one of the ROBINS-I domains) in a sensitivity analysis exploring confounding. MAIN RESULTS: We identified 23 non-randomised studies that met the inclusion criteria of this review, of which 10 studies provided no outcome data for adults with ALL. We included the remaining 13 studies in the 'Risk of bias' assessment, in which we identified invalid control group definition in two studies and judged outcomes of nine studies to be at critical risk of bias in at least one of the ROBINS-I domains and outcomes of two studies at serious risk of bias. We did not assess the benefits of thromboprophylaxis, as no RCTs were included. In the main descriptive analysis of harms, we included two retrospective non-randomised studies with outcomes judged to be at serious risk of bias. One study evaluated antithrombin concentrates compared to no antithrombin concentrates. We are uncertain whether antithrombin concentrates have an effect on all-cause mortality (risk ratio (RR) 0.55, 95% confidence interval (CI) 0.26 to 1.19 (intention-to-treat analysis); one study, 40 participants; very low certainty of evidence). We are uncertain whether antithrombin concentrates have an effect on venous thromboembolism-related mortality (RR 0.10, 95% CI 0.01 to 1.94 (intention-to-treat analysis); one study, 40 participants; very low certainty of evidence). We do not know whether antithrombin concentrates have an effect on major bleeding, clinically relevant non-major bleeding, and quality of life in adults with ALL treated with asparaginase-based chemotherapy, as data were insufficient. The remaining study (224 participants) evaluated prophylaxis with low-molecular-weight heparin versus no prophylaxis. However, this study reported insufficient data regarding harms including all-cause mortality, major bleeding, venous thromboembolism-related mortality, clinically relevant non-major bleeding, heparin-induced thrombocytopenia, and quality of life. In the sensitivity analysis of harms, exploring the effect of confounding, we also included nine non-randomised studies with outcomes judged to be at critical risk of bias primarily due to uncontrolled confounding. Three studies (179 participants) evaluated the effect of antithrombin concentrates and six studies (1224 participants) evaluated the effect of prophylaxis with different types of heparins. When analysing all-cause mortality; venous thromboembolism-related mortality; and major bleeding (studies of heparin only) including all studies with extractable outcomes for each comparison (antithrombin and low-molecular-weight heparin), we observed small study sizes; few events; wide CIs crossing the line of no effect; and substantial heterogeneity by visual inspection of the forest plots. Although the observed heterogeneity could arise through the inclusion of a small number of studies with differences in participants; interventions; and outcome assessments, the likelihood that bias due to uncontrolled confounding was the cause of heterogeneity is inevitable. Subgroup analyses were not possible due to insufficient data. AUTHORS' CONCLUSIONS: We do not know from the currently available evidence, if thromboprophylaxis used for adults with ALL treated according to asparaginase-based regimens is associated with clinically appreciable benefits and acceptable harms. The existing research on this question is solely of non-randomised design, seriously to critically confounded, and underpowered with substantial imprecision. Any estimates of effect based on the existing insufficient evidence is very uncertain and is likely to change with future research.
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Cochrane Db Syst Rev · Oct 2020
Review Meta AnalysisLocal cooling for relieving pain from perineal trauma sustained during childbirth.
Perineal trauma is common during childbirth and may be painful. Contemporary maternity practice includes offering women numerous forms of pain relief, including the local application of cooling treatments. This Cochrane Review is an update of a review last updated in 2012. ⋯ There is limited very low-certainty evidence that may support the use of cooling treatments, in the form or ice packs or cold gel pads, for the relief of perineal pain in the first two days following childbirth. It is likely that concurrent use of several treatments is required to adequately address this issue, including prescription and non-prescription analgesia. Studies included in this review involved the use of cooling treatments for 10 to 20 minutes, and although no adverse effects were noted, these findings came from studies of relatively small numbers of women, or were not reported at all. The continued lack of high-certainty evidence of the benefits of cooling treatments should be viewed with caution, and further well-designed trials should be conducted.
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Pulmonary emboli (PE), or blood clots in the lungs,can be potentially fatal. Anticoagulation is the first line therapy to prevent PE. In some instances anticoagulation fails to prevent more emboli, or cannot be given because the person has a high risk of bleeding. Inferior vena caval filters (VCFs) are metal alloy devices that mechanically trap fragmented emboli from the deep leg veins en route to the pulmonary circulation. Retrievable filters are designed to be introduced and removed percutaneously. Although their deployment seems of theoretical benefit, their clinical efficacy and adverse event profile is unclear. This is the third update of a Cochrane Review first published in 2007. ⋯ Two of the six identified studies were relevant for current clinical settings. One showed no evidence of a benefit of retrievable filters in acute PE for the outcomes of PE, death, DVT and bleeding during the initial three months in people who can receive anticoagulation (moderate-certainty evidence). The other study did not show any benefit for prophylactic filter insertion in people who sustained multiple traumatic injuries, with respect to symptomatic PE, mortality, or lower extremity venous thrombosis (moderate-certainty evidence). We can draw no firm conclusions regarding filter efficacy in the prevention of PE from the remaining four RCTs identified in this review. Further trials are needed to assess vena caval filter effectiveness and safety, and clinical differences between various filter types.
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Cochrane Db Syst Rev · Oct 2020
ReviewFactors that impact on recruitment to randomised trials in health care: a qualitative evidence synthesis.
Randomised trials (also referred to as 'randomised controlled trials' or 'trials') are the optimal way to minimise bias in evaluating the effects of competing treatments, therapies and innovations in health care. It is important to achieve the required sample size for a trial, otherwise trialists may not be able to draw conclusive results leading to research waste and raising ethical questions about trial participation. The reasons why potential participants may accept or decline participation are multifaceted. Yet, the evidence of effectiveness of interventions to improve recruitment to trials is not substantial and fails to recognise these individual decision-making processes. It is important to synthesise the experiences and perceptions of those invited to participate in randomised trials to better inform recruitment strategies. ⋯ This qualitative evidence synthesis has provided comprehensive insight into the complexity of factors that influence a person's decision whether to participate in a trial. We developed key questions that trialists can ask when developing their recruitment strategy. In addition, our conceptual model emphasises the need for participant-centred approaches to recruitment. We demonstrated moderate to high level confidence in our findings, which in some way can be attributed to the large volume of highly relevant studies in this field. We recommend that these insights be used to direct or influence or underpin future recruitment strategies that are developed in a participant-driven way that ultimately improves trial conduct and reduces research waste.
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Cochrane Db Syst Rev · Oct 2020
Review Meta AnalysisHousehold interventions for secondary prevention of domestic lead exposure in children.
Lead exposure is a serious health hazard, especially for children. It is associated with physical, cognitive and neurobehavioural impairment in children. There are many potential sources of lead in the environment, therefore trials have tested many household interventions to prevent or reduce lead exposure. This is an update of a previously published review. ⋯ Based on available evidence, household educational interventions and environmental interventions (namely dust control measures) show no evidence of a difference in reducing blood lead levels in children as a population health measure. The evidence of the effects of environmental interventions on cognitive and neurobehavioural outcomes and adverse events is uncertain too. Further trials are required to establish the most effective intervention for reducing or even preventing further lead exposure. Key elements of these trials should include strategies to reduce multiple sources of lead exposure simultaneously using empirical dust clearance levels. It is also necessary for trials to be carried out in low- and middle-income countries and in differing socioeconomic groups in high-income countries.