A knowledge synthesis attempts to summarize all pertinent studies on a specific question, can improve the understanding of inconsistencies in diverse evidence, and can identify gaps in research evidence to define future research agendas. Knowledge synthesis activities in healthcare have largely focused on systematic reviews of interventions. However, a wider range of synthesis methods has emerged in the last decade addressing different types of questions (e.g., realist synthesis to explore mediating mechanisms and moderators of interventions). Many different knowledge synthesis methods exist in the literature across multiple disciplines, but locating these, particularly for qualitative research, present challenges. There is a need for a comprehensive manual for synthesis methods (quantitative/qualitative or mixed), outlining how these methods are related, and how to match the most appropriate knowledge synthesis method to answer a research question. The objectives of this scoping review are to: 1) conduct a systematic search of the literature for knowledge synthesis methods across multi-disciplinary fields; 2) compare and contrast the different knowledge synthesis methods; and, 3) map out the specific steps to conducting the knowledge syntheses to inform the development of a knowledge synthesis methods manual/tool.

Background: Refugees, and other forcibly displaced people, face mental distress and may be disproportionately affected by risk factors for suicide. Little is known about suicidal behaviour in these highly mobile populations because collecting timely, relevant, and reliable data is challenging. Methods and findings: A systematic review was performed to identify studies of any design reporting on suicide, suicide attempts, or suicidal ideation among populations of displaced people. A sensitive electronic database search was performed in August 2020, and all retrieved studies were screened for relevance by two authors. Studies were categorised by the population being evaluated: refugees granted asylum, refugees living in temporary camps, asylum seekers, or internally displaced people. We distinguished between whether the sampling procedure in the studies was likely to be representative, or the sample examined a specific non-representative subgroup of displaced people (such as those already diagnosed with mental illness). Data on the rates of suicide or the prevalence of suicide attempts or suicidal ideation were extracted by one reviewer and verified by a second reviewer from each study and converted to common metrics. After screening 4347 articles, 87 reports of 77 unique studies were included. Of these, 53 were studies in representative samples, and 24 were based on samples of specific target populations. Most studies were conducted in high-income countries, and the most studied population subgroup was refugees granted asylum. There was substantial heterogeneity across data sources and measurement instruments utilised. Sample sizes of displaced people ranged from 33 to 196,941 in studies using general samples. Suicide rates varied considerably, from 4 to 290 per 100,000 person-years across studies. Only 8 studies were identified that compared suicide rates with the host population. The prevalence of suicide attempts ranged from 0.14% to 15.1% across all studies and varied according to the prevalence period evaluated. Suicidal ideation prevalence varied from 0.17% to 70.6% across studies. Among refugees granted asylum, there was evidence of a lower risk of suicide compared with the host population in 4 of 5 studies. In contrast, in asylum seekers there was evidence of a higher suicide risk in 2 of 3 studies, and of a higher risk of suicidal ideation among refugees living in camps in 2 of 3 studies compared to host populations. Conclusion: While multiple studies overall have been published in the literature on this topic, the evidence base is still sparse for refugees in camps, asylum seekers, and internally displaced people. Less than half of the included studies reported on suicide or suicide attempt outcomes, with most reporting on suicidal ideation. International research networks could usefully define criteria, definitions, and study designs to help standardise and facilitate more research in this important area. Registration: PROSPERO CRD42019137242.

Background: Branched-chain amino acids (BCAAs; leucine, isoleucine, and valine) are essential amino acids involved in immune responses, and may have roles in protein malnutrition and sarcopenia. Furthermore, certain liver diseases have been associated with a decreased Fischer’s ratio (BCAAs to aromatic amino acids; phenylalanine, tyrosine, and tryptophan). We aimed to evaluate the safety and efficacy of BCAAs use in patients with cancer undergoing surgery. Methods: MEDLINE, Embase, and CENTRAL were searched (inception to July 24, 2020) for randomized controlled trials (RCTs) and comparative observational studies in English evaluating BCAAs (alone or in combinations) during the oncological peri-operative period. Study selection, data extraction, and quality appraisal were done in duplicate. RCT risk-of-bias was appraised using Cochrane Risk-of-Bias tool, and observational studies’ quality assessment was conducted with Newcastle-Ottawa Scale. Meta-analyses were conducted when appropriate. Results: 20 articles were included comprising 13 RCTs and 6 observational cohort studies in 7 reports and 2019 total participants overall. Among 13 RCTs, 77% involved liver cancer. Methodological study quality scored substantial risk-of-bias across most RCTs. Meta-analysis of RCTs found a 38% decreased risk of post-operative infections in BCAAs group compared to controls (RR = 0.62; 95% CI = 0.44 to 0.87; P = .006; number of RCTs, k = 6; total sample size, N = 389; I² = 0%). BCAAs were also found to be beneficial for ascites (RR = 0.55; 95% CI = 0.35 to 0.86; P = .008; k = 4; N = 296; I² = 0%), body weight (MD = 3.24 kg; 95% CI = 0.44 to 6.04; P = .02; k = 3; N = 196; I² = 24%), and hospitalization length (MD = −2.07 days; 95% CI = −3.97 to −0.17; P = .03; k = 5; N = 362; I² = 59%). No differences were found between BCAAs and controls for mortality, recurrence, other post-operative complications (liver failure, edema, pleural effusion), blood loss, quality of life, ammonia level, and prothrombin time. No serious adverse events were related to BCAAs; however, serious adverse events were reported due to intravenous catheters. No safety concerns from observational studies were identified. Conclusions: Branched-chain amino acids during the oncological surgical period demonstrated promise in reducing important post-operative morbidity from infections and ascites compared to controls. Blinded, placebo-controlled confirmatory trials of higher methodological quality are warranted, especially using oral, short-term BCAAs-enriched supplements within the context of recent ERAS programs. PROSPERO registration: CRD42018086168.

Background: Objectives were to evaluate probiotics safety and efficacy in oncological surgery. Methods: Systematic review methodology guided by Cochrane, PRISMA, SWiM, and CIOMS. Protocol registered on PROSPERO (CRD42018086168). Results: 36 RCTs (on 3305 participants) and 6 nonrandomized/observational studies were included, mainly on digestive system cancers. There was evidence of a beneficial effect on preventing infections, with 70% of RCTs’ (21/30) direction of effect favoring probiotics. However, five RCTs (17%) favored controls for infections, including one trial with RR 1.57 (95% CI: 0.79, 3.12). One RCT that changed (balanced) its antibiotics protocol after enrolling some participants had mortality risk RR 3.55 (95% CI: 0.77, 16.47; 7/64 vs. 2/65 deaths). The RCT identified with the most promising results overall administered an oral formulation of Lactobacillus acidophilus LA-5 + Lactobacillus plantarum + Bifidobacterium lactis BB-12 + Saccharomyces boulardii. Methodological quality appraisals revealed an overall substantial risk-of-bias, with only five RCTs judged as low risk-of-bias. Conclusions: This large evidence synthesis found encouraging results from most formulations, though this was contrasted by potential harms from a few others, thus validating the literature that “probiotics” are not homogeneous microorganisms. Given microbiome developments and infections morbidity, further high-quality research is warranted using those promising probiotics identified herein.

Background: We aim to evaluate the safety and efficacy of mistletoe extract (ME) use during the oncological perioperative period. Methods: Details registered a priori on PROSPERO (CRD42018086168). Results: Seven RCTs (comprising 663 participants in nine reports) and three nonrandomized studies were included. In five RCTs, ME was evaluated as adjunctive care and the control group had no additional intervention, whereas in two RCTs, ME was compared head-to-head against common cancer treatments (i.e., etoposide or bacillus Calmette-Guérin) with the intervention groups not receiving standard care. Meta-analyses found no evidence for a difference between ME and no added therapy for mortality and recurrence (RR, 95% CI: 1.00, 0.79–1.27; and 1.03, 0.79–1.33, respectively). Two RCTs reported beneficial effects of ME on immune cells, specifically natural killer cells, in colorectal cancer, and one RCT reported quality of life improvement. Two RCTs reported ME discontinuations due to adverse events and grade 3/4 toxicities. Nevertheless, no safety signals were detected from these 10 studies. Quality appraisal revealed a substantial risk of bias. Conclusions: Preliminary data are encouraging for mistletoe extracts, particularly in the context of colorectal cancer. However, the evidence is limited by the number of studies, an evaluation of different outcomes, and methodological limitations. Further high-quality research is warranted.