Are systematic reviews addressing nutrition for cancer prevention trustworthy? A systematic survey of quality and risk of bias.

CONTEXT: The last 30 years have yielded a vast number of systematic reviews and/or meta-analyses addressing the link between nutrition and cancer risk. OBJECTIVE: The aim of this survey was to assess overall quality and potential for risk of bias in systematic reviews and meta-analyses (SRMAs) that examined the role of nutrition in cancer prevention. DATA SOURCES: MEDLINE, Embase, and the Cochrane Library databases were searched (last search performed November 2018). STUDY SELECTION: Studies identified as SRMAs that investigated a nutritional or dietary intervention or exposure for cancer prevention in the general population or in people at risk of cancer and in which primary studies had a comparison group were eligible for inclusion. Screening, data extraction, and quality assessment were conducted independently by 2 reviewers. DATA EXTRACTION: Altogether, 101 studies were randomly selected for analysis. The methodological quality and risk of bias were evaluated using the AMSTAR-2 and ROBIS tools, respectively. RESULTS: Most SRMAs included observational studies. Less than 10% of SRMAs reported a study protocol, and only 51% of SRMAs assessed the risk of bias in primary studies. Most studies conducted subgroup analyses, but only a few reported tests of interaction or specified subgroups of interest a priori. Overall, according to AMSTAR-2, only 1% of SRMAs were of high quality, while 97% were of critically low quality. Only 3% had a low risk of bias, according to ROBIS. CONCLUSIONS: This systematic survey revealed substantial limitations with respect to quality and risk of bias of SRMAs. SRMAs examining nutrition and cancer prevention cannot be considered trustworthy, and results should be interpreted with caution. Peer reviewers as well as users of SRMAs should be advised to use the AMSTAR-2 and/or ROBIS instruments to help to determine the overall quality and risk of bias of SRMAs. SYSTEMATIC REVIEW REGISTRATION: PROSPERO registration number CRD42019121116.

Anti-cytokine targeted therapies for ANCA-associated vasculitis.

BACKGROUND: Anti-neutrophilic cytoplasmic antibodies (ANCA)-associated vasculitis (AAV) are a group of rare auto-inflammatory diseases that affects mainly small vessels. AAV includes: granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA) and eosinophilic granulomatosis with polyangiitis (EGPA). Anti-cytokine targeted therapy uses biological agents capable of specifically targeting and neutralising cytokine mediators of the inflammatory response. OBJECTIVES: To assess the benefits and harms of anti-cytokine targeted therapy for adults with AAV. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (2019, Issue 7), MEDLINE and Embase up to 16 August 2019. We also examined reference lists of articles, clinical trial registries, websites of regulatory agencies and contacted manufacturers. SELECTION CRITERIA: Randomised controlled trials (RCTs) or controlled clinical trials of targeted anti-cytokine therapy in adults (18 years or older) with AAV compared with placebo, standard therapy or another modality and anti-cytokine therapy of different type or dose. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane. MAIN RESULTS: We included four RCTs with a total of 440 participants (mean age 48 to 56 years). We analysed the studies in three groups: 1) mepolizumab (300 mg; three separate injections every four weeks for 52 weeks) versus placebo in participants with relapsing or refractory EGPA; 2) belimumab (10 mg/kg on days 0, 14, 28 and every 28 days thereafter until 12 months after the last participant was randomised) or etanercept (25 mg twice a week) with standard therapy (median 25 months) versus placebo with standard therapy (median 19 months) in participants with GPA/MPA; and 3) infliximab (3 mg/kg on days 1 and 14, before the response assessment on day 42) versus rituximab (0.375g/m2 on days 1, 8, 15 and 22) in participants with refractory GPA for up to 12 months. None of the studies were assessed as low risk of bias in all domains: one study did not report randomisation or blinding methods clearly. Three studies were at high risk and one study was at unclear risk of bias for selective outcome reporting. One trial with 136 participants with relapsing or refractory EGPA compared mepolizumab with placebo during 52 weeks of follow-up and observed one death in the mepolizumab group (1/68, 1.5%) and none in the placebo group (0/68, 0%) (Peto odds ratio (OR) 7.39, 95% confidence interval (CI) 0.15 to 372.38; low-certainty evidence). Low-certainty evidence suggests that more participants in the mepolizumab group had ≥ 24 weeks of accrued remission over 52 weeks compared to placebo (27.9% versus 2.9%; risk ratio (RR) 9.5, 95% CI 2.30 to 39.21), and durable remission within the first 24 weeks sustained until week 52 (19.1% mepolizumab versus 1.5% placebo; RR 13.0, 95% CI 1.75 to 96.63; number needed to treat for an additional beneficial outcome (NNTB) 6, 95% Cl 4 to 13). Mepolizumab probably decreases risk of relapse (55.8% versus 82.4%; RR 0.68, 95% CI 0.53 to 0.86; NNTB 4, 95% CI 3 to 9; moderate-certainty evidence). There was low-certainty evidence regarding similar frequency of adverse events (AEs): total AEs (96.9% versus 94.1%; RR 1.03, 95% CI 0.96 to 1.11), serious AEs (17.7% versus 26.5%; RR 0.67, 95% CI 0.35 to 1.28) and withdrawals due to AEs (2.9% versus 1.5%; RR 2.00, 95% CI 0.19 to 21.54). Disease flares were not measured. Based on two trials with different follow-up periods (mean of 27 months for etanercept study; up to four years for belimumab study) including people with GPA (n = 263) and a small group of participants with MPA (n = 22) analysed together, we found low-certainty evidence suggesting that adding an active drug (etanercept or belimumab) to standard therapy does not increase or reduce mortality (3.4% versus 1.4%; Peto OR 2.45, 95% CI 0.55 to 10.97). Etanercept may have little or no effect on remission (92.3% versus 89.5%; RR 0.97, 95% CI 0.89 to 1.07), durable remission (70% versus 75.3%; RR 0.93, 95% CI 0.77 to 1.11; low-certainty evidence) and disease flares (56% versus 57.1%; RR 0.98, 95% CI 0.76 to 1.27; moderate-certainty evidence). Low-certainty evidence suggests that belimumab does not increase or reduce major relapse (1.9% versus 0%; RR 2.94, 95% CI 0.12 to 70.67) or any AE (92.5% versus 82.7%; RR 1.12, 95% CI 0.97 to 1.29). Low-certainty evidence suggests a similar frequency of serious or severe AEs (47.6% versus 47.6%; RR 1.00, 95% CI 0.80 to 1.27), but more frequent withdrawals due to AEs in the active drug group (11.2%) compared to the placebo group (4.2%), RR 2.66, 95% CI 1.07 to 6.59). One trial involving 17 participants with refractory GPA compared infliximab versus rituximab added to steroids and cytotoxic agents for 12 months. One participant died in each group (Peto OR 0.88, 95% CI, 0.05 to 15.51; 11% versus 12.5%). We have very low-certainty evidence for remission (22% versus 50%, RR 0.44, 95% Cl 0.11 to 1.81) and durable remission (11% versus 50%, RR 0.22, 95% CI 0.03 to 1.60), any severe AE (22.3% versus 12.5%; RR 1.78, 95% CI 0.2 to 16.1) and withdrawals due to AEs (0% versus 0%; RR 2.70, 95% CI 0.13 to 58.24). Disease flare/relapse and the frequency of any AE were not reported. AUTHORS' CONCLUSIONS: We found four studies but concerns about risk of bias and small sample sizes preclude firm conclusions. We found moderate-certainty evidence that in patients with relapsing or refractory EGPA, mepolizumab compared to placebo probably decreases disease relapse and low-certainty evidence that mepolizumab may increase the probability of accruing at least 24 weeks of disease remission. There were similar frequencies of total and serious AEs in both groups, but the study was too small to reliably assess these outcomes. Mepolizumab may result in little to no difference in mortality. However, there were very few events. In participants with GPA (and a small subgroup of participants with MPA), etanercept or belimumab may increase the probability of withdrawal due to AEs and may have little to no impact on serious AEs. Etanercept may have little or no impact on durable remission and probably does not reduce disease flare.

Public media as a tool for dissemination of evidence-based information.

The internet is becoming a more and more popular source of all kinds of information. The quantity of web pages that offer information and advice about health is increasing, though the quality is often not rising. The aim of the presented work is to describe advantages and difficulties connected with dissemination of evidence-based information in social media. Using Polish Facebook and Twitter profiles over the course of 2 years, we posted about 400 posts and tweets. We analysed types of topics and some strategies to broaden our audience. On basis of our results, we found that probably inconclusive results make review summaries unintelligible and not popular in public media, though the broad reach of posts in public media does not implicate that the message was understood. Even though numerous efforts were put into guidelines on how to write a proper plain language summary of the systematic review, there is still space for improvement.