Long-term and serious harms of medical cannabis and cannabinoids for chronic pain: a systematic review of non-randomised studies.

OBJECTIVE: To establish the prevalence of long-term and serious harms of medical cannabis for chronic pain. DESIGN: Systematic review and meta-analysis. DATA SOURCES: MEDLINE, EMBASE, PsycINFO and CENTRAL from inception to 1 April 2020. STUDY SELECTION: Non-randomised studies reporting on harms of medical cannabis or cannabinoids in adults or children living with chronic pain with ≥4 weeks of follow-up. DATA EXTRACTION AND SYNTHESIS: A parallel guideline panel provided input on the design and interpretation of the systematic review, including selection of adverse events for consideration. Two reviewers, working independently and in duplicate, screened the search results, extracted data and assessed risk of bias. We used random-effects models for all meta-analyses and the Grades of Recommendations, Assessment, Development and Evaluation approach to evaluate the certainty of evidence. RESULTS: We identified 39 eligible studies that enrolled 12 143 adult patients with chronic pain. Very low certainty evidence suggests that adverse events are common (prevalence: 26.0%; 95% CI 13.2% to 41.2%) among users of medical cannabis for chronic pain, particularly any psychiatric adverse events (prevalence: 13.5%; 95% CI 2.6% to 30.6%). Very low certainty evidence, however, indicates serious adverse events, adverse events leading to discontinuation, cognitive adverse events, accidents and injuries, and dependence and withdrawal syndrome are less common and each typically occur in fewer than 1 in 20 patients. We compared studies with <24 weeks and ≥24 weeks of cannabis use and found more adverse events reported among studies with longer follow-up (test for interaction p<0.01). Palmitoylethanolamide was usually associated with few to no adverse events. We found insufficient evidence addressing the harms of medical cannabis compared with other pain management options, such as opioids. CONCLUSIONS: There is very low certainty evidence that adverse events are common among people living with chronic pain who use medical cannabis or cannabinoids, but that few patients experience serious adverse events.

Effects of inulin-type fructans supplementation on cardiovascular disease risk factors: a protocol for a systematic review and meta-analysis of randomised controlled trials.

INTRODUCTION: This review aims to assess the effects of dietary supplementation with inulin-type fructans (ITF) compared with no supplementation on cardiovascular disease risk factors in adults and assess the quality of trial reporting using the Consolidated Standards of Reporting Trials (CONSORT) and CONSORT for abstract (CONSORT-A) checklists. METHODS AND ANALYSIS: We will search randomised controlled trials (RCTs) in MEDLINE, EMBASE, CINAHL, Emcare, AMED and the Cochrane Database of Systematic Reviews from inception to 31 March 2022, without any language restrictions. The RCTs need to administer ITF in adults for at least 2 weeks and assess effects on at least one cardiovascular risk factor. We will exclude RCTs that (1) assessed the postprandial effects of ITF; (2) included pregnant or lactating participants; (3) enrolled participants undergoing treatment that might affect the response to ITF. We will assess the study risk of bias (RoB) using V.2 of the Cochrane RoB tool for RCTs (RoB 2) and the certainty of the evidence using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach. We will pool data using a random-effects model. We will use the χ2 test to compare compliance of CONSORT and CONSORT-A checklists and Poisson regression to identify factors associated with better reporting. ETHICS AND DISSEMINATION: Ethics approval is not required for secondary analysis of already published data. We will publish the reviews in a peer-review journal. PROSPERO REGISTRATION NUMBER: CRD42019136745.

Consistency of covid-19 trial preprints with published reports and impact for decision making: retrospective review.

Objective: To assess the trustworthiness (ie, complete and consistent reporting of key methods and results between preprint and published trial reports) and impact (ie, effects of preprints on meta-analytic estimates and the certainty of evidence) of preprint trial reports during the covid-19 pandemic. Design: Retrospective review. Data sources: World Health Organization covid-19 database and the Living Overview of the Evidence (L-OVE) covid-19 platform by the Epistemonikos Foundation (up to 3 August 2021). Main outcome measures: Comparison of characteristics of covid-19 trials with and without preprints, estimates of time to publication of covid-19 preprints, and description of differences in reporting of key methods and results between preprints and their later publications. For the effects of eight treatments on mortality and mechanical ventilation, the study comprised meta-analyses including preprints and excluding preprints at one, three, and six months after the first trial addressing the treatment became available either as a preprint or publication (120 meta-analyses in total, 60 of which included preprints and 60 of which excluded preprints) and assessed the certainty of evidence using the GRADE framework. Results: Of 356 trials included in the study, 101 were only available as preprints, 181 as journal publications, and 74 as preprints first and subsequently published in journals. The median time to publication of preprints was about six months. Key methods and results showed few important differences between trial preprints and their subsequent published reports. Apart from two (3.3%) of 60 comparisons, point estimates were consistent between meta-analyses including preprints versus those excluding preprints as to whether they indicated benefit, no appreciable effect, or harm. For nine (15%) of 60 comparisons, the rating of the certainty of evidence was different when preprints were included versus being excluded-the certainty of evidence including preprints was higher in four comparisons and lower in five comparisons. Conclusion: No compelling evidence indicates that preprints provide results that are inconsistent with published papers. Preprints remain the only source of findings of many trials for several months-an unsuitable length of time in a health emergency that is not conducive to treating patients with timely evidence. The inclusion of preprints could affect the results of meta-analyses and the certainty of evidence. Evidence users should be encouraged to consider data from preprints.