Effects of adding adjunctive hyperbaric oxygen therapy to standard wound care for diabetic foot ulcers: a protocol for a systematic review with meta-analysis and trial sequential analysis.

INTRODUCTION: Diabetic foot ulcer represents a major health problem globally. Preliminary studies have indicated that systemic treatment of diabetic foot ulcer patients with hyperbaric oxygen therapy have beneficial effects on wound healing, risk of amputation, glycaemic control, atherosclerosis, inflammatory markers and other clinical and laboratory parameters. This protocol for a systematic review aims at identifying the beneficial and harmful effects of adding hyperbaric oxygen therapy to standard wound care for diabetic foot ulcers. METHODS AND ANALYSIS: This protocol was performed following the recommendations of the Cochrane Collaboration and the eight-step assessment procedure suggested by Jakobsen and colleagues. We plan to include all relevant randomised clinical trials assessing the effects of hyperbaric oxygen therapy in the treatment of diabetic foot ulcer versus any control group with any intervention defined as standard wound care or similar, together with sham interventions. Our primary outcome will be: all-cause mortality, serious adverse events and quality of life. Our secondary outcomes will be: healing of index wound, major amputation and wound infection. Any eligible trial will be assessed and classified as either high risk of bias or low risk of bias, and our conclusions will be based on trials with low risk of bias. The analyses of the extracted data will be performed using Review Manager 5 and Trial Sequential Analysis. For both our primary and secondary outcomes, we will create a 'Summary of Findings' table and use GRADE (Grading of Recommendations Assessment, Development and Evaluation) assessment to assess the quality of the evidence. ETHICS AND DISSEMINATION: We use publicly accessible documents as evidence, there is no participant involvement at an individual level and an institutional ethics approval is not required. The results of the review will be sought published in a peer-reviewed journals, also in the event of insignificant results or null results, and thereby it will be disseminated to clinicians and public available. PROSPERO REGISTRATION NUMBER: CRD42019139256.

Dynamic LED-light versus static LED-light for depressed inpatients: study protocol for a randomised clinical study.

INTRODUCTION: Retrospective studies conducted in psychiatric inpatient wards have shown a relation between the intensity of daylight in patient rooms and the length of stay, pointing to an antidepressant effect of ambient lighting conditions. Light therapy has shown a promising antidepressant effect when administered from a light box. The emergence of light-emitting diode (LED) technology has made it possible to build luminaires into rooms and to dynamically mimic the spectral and temporal distribution of daylight. The objective of this study is to investigate the antidepressant efficacy of a newly developed dynamic LED-lighting system installed in an inpatient ward. METHODS AND ANALYSIS: In all, 150 inpatients with a major depressive episode, as part of either a major depressive disorder or as part of a bipolar disorder, will be included. The design is a two-arm 1:1 randomised study with a dynamic LED-lighting arm and a static LED-lighting arm, both as add-on to usual treatment in an inpatient psychiatric ward. The primary outcome is the baseline adjusted score on the 6-item Hamilton Depression Rating Scale at week 3. The secondary outcomes are the mean score on the Suicidal Ideation Attributes Scale at week 3, the mean score on the 17-item Hamilton Depression Rating Scale at week 3 and the mean score on the World Health Organisation Quality of Life-BREF (WHOQOL-BREF) at week 3. The spectral distribution of daylight and LED-light, with a specific focus on light mediated through the intrinsically photosensitive retinal ganglion cells, will be measured. Use of light luminaires will be logged. Assessors of Hamilton Depression Rating Scale scores and data analysts will be blinded for treatment allocation. The study was initiated in May 2019 and will end in December 2021. ETHICS AND DISSEMINATION: No ethical issues are expected. Results will be published in peer-reviewed journals, disseminated electronically and in print and presented at symposia. TRIAL REGISTRATION NUMBER: NCT03821506; Pre-results.

Xiao Chai Hu Tang, a herbal medicine, for chronic hepatitis B.

BACKGROUND: Chronic hepatitis B is associated with high morbidity and mortality. Chronic hepatitis B requires long-term management aiming at reduction of the risks of hepatocellular inflammatory necrosis, liver fibrosis, decompensated liver cirrhosis, liver failure, and liver cancer, and improving health-related quality of life. The Chinese herbal medicine formula Xiao Chai Hu Tang has been used to decrease discomfort and replication of the virus in people with chronic hepatitis B. However, the benefits and harms of Xiao Chai Hu Tang formula have never been established with rigorous review methodology. OBJECTIVES: To assess the benefits and harms of Xiao Chai Hu Tang formula versus placebo or no intervention in people with chronic hepatitis B. SEARCH METHODS: We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, CENTRAL, MEDLINE Ovid, Embase Ovid, and seven other databases to 1 March 2019. We also searched the World Health Organization International Clinical Trials Registry Platform (www.who.int/ictrp), ClinicalTrials.gov (www.clinicaltrials.gov/), and the Chinese Clinical Trial Registry for ongoing or unpublished trials to 1 March 2019. SELECTION CRITERIA: We included randomised clinical trials, irrespective of publication status, language, and blinding, comparing Xiao Chai Hu Tang formula versus no intervention or placebo in people with chronic hepatitis B. We included participants of any sex and age, diagnosed with chronic hepatitis B according to guidelines or as defined by the trialists. We allowed co-interventions when the co-interventions were administered equally to all the intervention groups. DATA COLLECTION AND ANALYSIS: Review authors independently retrieved data from reports and after correspondence with investigators. Our primary outcomes were all-cause mortality, serious adverse events, and health-related quality of life. Our secondary outcomes were hepatitis B-related mortality, hepatitis B-related morbidity, and adverse events considered 'not to be serious'. We presented the meta-analysed results as risk ratios (RR) with 95% confidence intervals (CI). We assessed the risks of bias using risk of bias domains with predefined definitions. We used GRADE methodology to evaluate our certainty in the evidence. MAIN RESULTS: We included 10 randomised clinical trials with 934 participants, but only five trials with 490 participants provided data for analysis. All the trials compared Xiao Chai Hu Tang formula with no intervention. All trials appeared to have been conducted and published only in China. The included trials assessed heterogeneous forms of Xiao Chai Hu Tang formula, administered for three to eight months. One trial included participants with hepatitis B and comorbid tuberculosis, and one trial included participants with hepatitis B and liver cirrhosis. The remaining trials included participants with hepatitis B only. All the trials were at high risk of bias, and the certainty of evidence for all outcomes that provided data for analyses was very low. We downgraded the evidence by one or two levels because of outcome risk of bias, inconsistency or heterogeneity of results (opposite direction of effect), indirectness of evidence (use of surrogate outcomes instead of clinically relevant outcomes), imprecision of results (the CIs were wide), and publication bias (small sample size of the trials). Additionally, 47 trials lacked the necessary methodological information needed to ensure the inclusion of these trials in our review. None of the included trials aimed to assess clinically relevant outcomes such as all-cause mortality, serious adverse events, health-related quality of life, hepatitis B-related mortality, or hepatitis B-related morbidity. The effects of Xiao Chai Hu Tang formula on the proportion of participants with adverse events considered 'not to be serious' is uncertain (RR 0.43, 95% CI 0.02 to 11.98; I2 = 69%; very low-certainty evidence). Only three trials with 222 participants reported the proportion of people with detectable hepatitis B virus DNA (HBV-DNA), but the evidence that Xiao Chai Hu Tang formula reduces the presence of HBV-DNA in the blood (a surrogate outcome) is uncertain (RR 0.62, 95% CI 0.45 to 0.85; I2 = 0%; very low-certainty evidence). Only two trials with 160 participants reported the proportion of people with detectable hepatitis B virus e-antigen (HBeAg; a surrogate outcome) (RR 0.72, 95% CI 0.50 to 1.02; I2 = 38%; very low-certainty evidence) and the evidence is uncertain. The evidence is also uncertain for separately reported adverse events considered 'not to be serious'. FUNDING: two of the 10 included trials received academic funding from government or hospital. None of the remaining eight trials reported information on funding. AUTHORS' CONCLUSIONS: The clinical effects of Xiao Chai Hu Tang formula for chronic hepatitis B remain unclear. The included trials were small and of low methodological quality. Despite the wide use of Xiao Chai Hu Tang formula, we lack data on all-cause mortality, serious adverse events, health-related quality of life, hepatitis B-related mortality, and hepatitis B-related morbidity. The evidence in this systematic review comes from data obtained from a maximum three trials. We graded the certainty of evidence as very low for adverse events considered not to be serious and the surrogate outcomes HBeAg and HBV-DNA. We found a large number of trials which lacked clear description of their design and conduct, and hence, these trials are not included in the present review. As all identified trials were conducted in China, there might be a concern about the applicability of this review outside China. Large-sized, high-quality randomised sham-controlled trials with homogeneous groups of participants and transparent funding are lacking.

Acupuncture for chronic hepatitis B.

BACKGROUND: Chronic hepatitis B is a liver disease associated with high morbidity and mortality. Chronic hepatitis B requires long-term management aiming to reduce the risks of hepatocellular inflammatory necrosis, liver fibrosis, decompensated liver cirrhosis, liver failure, and liver cancer, as well as to improve health-related quality of life. Acupuncture is being used to decrease discomfort and improve immune function in people with chronic hepatitis B. However, the benefits and harms of acupuncture still need to be established in a rigorous way. OBJECTIVES: To assess the benefits and harms of acupuncture versus no intervention or sham acupuncture in people with chronic hepatitis B. SEARCH METHODS: We undertook electronic searches of the Cochrane Hepato-Biliary Group Controlled Trials Register, CENTRAL, MEDLINE, Embase, LILACS, Science Citation Index Expanded, Conference Proceedings Citation Index - Science, China National Knowledge Infrastructure (CNKI), Chongqing VIP (CQVIP), Wanfang Data, and SinoMed to 1 March 2019. We also searched the World Health Organization International Clinical Trials Registry Platform (www.who.int/ictrp), ClinicalTrials.gov (www.clinicaltrials.gov/), and the Chinese Clinical Trial Registry (ChiCTR) for ongoing or unpublished trials until 1 March 2019. SELECTION CRITERIA: We included randomised clinical trials, irrespective of publication status, language, and blinding, comparing acupuncture versus no intervention or sham acupuncture in people with chronic hepatitis B. We included participants of any sex and age, diagnosed with chronic hepatitis B as defined by the trialists or according to guidelines. We allowed co-interventions when the co-interventions were administered equally to all intervention groups. DATA COLLECTION AND ANALYSIS: Review authors in pairs individually retrieved data from reports and through correspondence with investigators. Primary outcomes were all-cause mortality, proportion of participants with one or more serious adverse events, and health-related quality of life. Secondary outcomes were hepatitis B-related mortality, hepatitis B-related morbidity, and adverse events considered not to be serious. We presented the pooled results as risk ratios (RRs) with 95% confidence intervals (CIs). We assessed the risks of bias using risk of bias domains with predefined definitions. We put more weight on the estimate closest to zero effect when results with fixed-effect and random-effects models differed. We evaluated the certainty of evidence using GRADE. MAIN RESULTS: We included eight randomised clinical trials with 555 randomised participants. All included trials compared acupuncture versus no intervention. These trials assessed heterogeneous acupuncture interventions. All trials used heterogeneous co-interventions applied equally in the compared groups. Seven trials included participants with chronic hepatitis B, and one trial included participants with chronic hepatitis B with comorbid tuberculosis. All trials were assessed at overall high risk of bias, and the certainty of evidence for all outcomes was very low due to high risk of bias for each outcome, imprecision of results (the confidence intervals were wide), and publication bias (small sample size of the trials, and all trials were conducted in China). Additionally, 79 trials lacked the necessary methodological information to ensure their inclusion in our review.None of the included trials aim to assess all-cause mortality, serious adverse events, health-related quality of life, hepatitis B-related mortality, and hepatitis B-related morbidity. We are uncertain whether acupuncture, compared with no intervention, has an effect regarding adverse events considered not to be serious (RR 0.67, 95% CI 0.43 to 1.06; I² = 0%; 3 trials; 203 participants; very low-certainty evidence) or detectable hepatitis B e-antigen (HBeAg) (RR 0.64, 95% CI 0.11 to 3.68; I² = 98%; 2 trials; 158 participants; very low-certainty evidence). Acupuncture showed a reduction in detectable hepatitis B virus (HBV) DNA (a non-validated surrogate outcome; RR 0.45, 95% CI 0.27 to 0.74; 1 trial, 58 participants; very low-certainty evidence). We are uncertain whether acupuncture has an effect regarding the remaining separately reported adverse events considered not to be serious.Three of the eight included trials received academic funding from government or hospital. None of the remaining five trials reported information on funding. AUTHORS' CONCLUSIONS: The clinical effects of acupuncture for chronic hepatitis B remain unknown. The included trials lacked data on all-cause mortality, health-related quality of life, serious adverse events, hepatitis-B related mortality, and hepatitis-B related morbidity. The vast number of excluded trials lacked clear descriptions of their design and conduct. Whether acupuncture influences adverse events considered not to be serious is uncertain. It remains unclear if acupuncture affects HBeAg, and if it is associated with reduction in detectable HBV DNA. Based on available data from only one or two small trials on adverse events considered not to be serious and on the surrogate outcomes HBeAg and HBV DNA, the certainty of evidence is very low. In view of the wide usage of acupuncture, any conclusion that one might try to draw in the future should be based on data on patient and clinically relevant outcomes, assessed in large, high-quality randomised sham-controlled trials with homogeneous groups of participants and transparent funding.

Radix Sophorae flavescentis versus other drugs or herbs for chronic hepatitis B.

BACKGROUND: Hepatitis B virus (HBV) infection is a liver disease caused by hepatitis B virus, which may lead to serious complications such as cirrhosis and hepatocellular carcinoma. People with HBV infection may also have coinfections including HIV and other hepatitis viruses (hepatitis C or D), and coinfections may increase the risk of all-cause mortality. Chronic HBV infection increases morbidity, psychological stress, and it is an economic burden on people with chronic hepatitis B and their families. Radix Sophorae flavescentis, a herbal medicine, is administered mostly in combination with other drugs or herbs. It is believed that it decreases discomfort and prevents the replication of the virus in people with chronic hepatitis B. However, the benefits and harms of Radix Sophorae flavescentis on patient-centred outcomes are unknown, and its wide usage has never been established with rigorous review methodology. OBJECTIVES: To assess the benefits and harms of Radix Sophorae flavescentis versus other drugs or herbs in people with chronic hepatitis B. SEARCH METHODS: We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, CENTRAL, MEDLINE, Embase, and seven other databases to December 2018. We also searched the World Health Organization International Clinical Trials Registry Platform (www.who.int/ictrp), ClinicalTrials.gov (www.clinicaltrials.gov/), and the Chinese Clinical Trial Registry for ongoing or unpublished trials to December 2018. SELECTION CRITERIA: We included randomised clinical trials, irrespective of publication status, language, or blinding, comparing Radix Sophorae flavescentis versus other drugs or herbs for people with chronic hepatitis B. In addition to chronic hepatitis B, participants could also have had cirrhosis, hepatocellular carcinoma, or any other concomitant disease. We excluded polyherbal blends containing Radix Sophorae flavescentis. We allowed cointerventions when the cointerventions were administered equally to all intervention groups. DATA COLLECTION AND ANALYSIS: Review authors in pairs individually retrieved data from published reports and after correspondence with investigators. Our primary outcomes were all-cause mortality, serious adverse events, and health-related quality of life. Our secondary outcomes were hepatitis B-related mortality, hepatitis B-related morbidity, and adverse events considered 'not to be serious'. We presented the meta-analysed results as risk ratios (RR) with 95% confidence intervals (CI). We assessed the risk of bias using domains with predefined definitions. We conducted Trial Sequential Analyses to control the risks of random errors. We used GRADE methodology to evaluate our certainty in the evidence (i.e. "the extent of our confidence that the estimates of the effect are correct or are adequate to support a particular decision or recommendation"). MAIN RESULTS: We included 10 randomised clinical trials with 898 participants. We judged all trials at high risk of bias. The trials covered oral capsules, intravenous infusion, intramuscular injection, and acupoint (a specifically chosen site of acupuncture) injection of Radix Sophorae flavescentis with a follow-up period from 1 to 12 months. The drugs being used as a comparator were lamivudine, adefovir, interferon, tiopronin, thymosin, or other Chinese herbs. Two trials included children up to 14 years old. Participants in one trial had cirrhosis in chronic hepatitis B. None of the trials reported all-cause mortality, health-related quality of life, serious adverse events, hepatitis B-related mortality, or morbidity. We are uncertain as to whether Radix Sophorae flavescentis has a beneficial or harmful effect on adverse events considered 'not to be serious' (RR 0.86, 95% CI 0.42 to 1.75; I2 = 0%; 2 trials, 163 participants; very low-certainty evidence), as well as if it decreases or increases the proportion of participants with detectable HBV-DNA (RR 1.14, 95% CI 0.81 to 1.63; I2 = 92%; 8 trials, 719 participants; very low-certainty evidence). Radix Sophorae flavescentis showed a reduction in the proportion of participants with detectable hepatitis B virus e-antigen (HBeAg) (RR 0.86, 95% CI 0.75 to 0.98; I2 = 43%; 7 trials, 588 participants; very low-certainty evidence).Two of the 10 trials were not funded, and one received academic funding. The remaining seven trials provided no information on funding.The randomisation process in another 109 trials was insufficiently reported to ensure the inclusion of any of these studies in our review. AUTHORS' CONCLUSIONS: The included trials lacked data on all-cause mortality, health-related quality of life, serious adverse events, hepatitis-B related mortality, and hepatitis-B related morbidity. The evidence on the effect of Radix Sophorae flavescentis on the proportion of participants with adverse events considered 'not to be serious' and on the proportion of participants with detectable HBV-DNA is still unclear. We advise caution regarding the results of Radix Sophorae flavescentis showing a reduction in the proportion of people with detectable HBeAg because the trials were at high risk of bias, because it is a non-validated surrogate outcome, and because of the very low certainty in the evidence. As we were unable to obtain information on a large number of studies regarding their trial design, we were deterred from including them in our review. Undisclosed funding may have influence on trial results and lead to poor design of the trial. In view of the wide usage of Radix Sophorae flavescentis, we need large, unbiased, high-quality placebo-controlled randomised trials assessing patient-centred outcomes.

Radix Sophorae flavescentis versus no intervention or placebo for chronic hepatitis B.

BACKGROUND: Hepatitis B virus (HBV) infection, a liver disease caused by hepatitis B virus, may lead to serious complications such as cirrhosis and hepatocellular carcinoma. People with HBV infection may have co-infections including HIV and other hepatitis viruses (hepatitis C or D), and co-infection may increase the risk of all-cause mortality. Chronic HBV infection increases morbidity and psychological stress and is an economic burden on people with chronic hepatitis B and their families. Radix Sophorae flavescentis, an herbal medicine, is administered most often in combination with other drugs or herbs. It is believed that it decreases discomfort and prevents replication of the virus in people with chronic hepatitis B. However, the benefits and harms of Radix Sophorae flavescentis for patient-centred outcomes are not known, and its wide usage has never been established with rigorous review methodology. OBJECTIVES: To assess the benefits and harms of Radix Sophorae flavescentis versus placebo or no intervention in people with chronic hepatitis B. SEARCH METHODS: We searched the Cochrane Hepato-Biliary Group Controlled Trials Register, CENTRAL, MEDLINE Ovid, Embase Ovid, LILACS, Science Citation Index Expanded, Conference Proceedings Citation Index - Science, China National Knowledge Infrastructure (CNKI), Chongqing VIP (CQVIP), Wanfang Data, and SinoMed. We also searched the World Health Organization International Clinical Trials Registry Platform (www.who.int/ictrp), ClinicalTrials.gov (www.clinicaltrials.gov/), and the Chinese Clinical Trial Registry for ongoing or unpublished trials. We conducted the last search in December 2018. SELECTION CRITERIA: We included randomised clinical trials, irrespective of publication status, language, or blinding, comparing Radix Sophorae flavescentis versus no intervention or placebo in people with chronic hepatitis B. We excluded polyherbal blends containing Radix Sophorae flavescentis. We allowed co-interventions when the co-interventions were administered equally to all intervention groups. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by The Cochrane Collaboration. Review authors in pairs retrieved data from individual published reports and after correspondence with investigators. Our primary outcomes were all-cause mortality, serious adverse events, and health-related quality of life. Our secondary outcomes were hepatitis B-related mortality, hepatitis B-related morbidity, and adverse events considered 'not to be serious'. We presented meta-analysed results as risk ratios (RRs) with 95% confidence intervals (CIs). We assessed risk of bias using domains with pre-defined definitions. We conducted Trial Sequential Analyses to control the risk of random errors. We used GRADE methodology to evaluate our certainty in the evidence (i.e. "the extent of our confidence that the estimates of the effect are correct or are adequate to support a particular decision or recommendation"). MAIN RESULTS: We included 35 randomised clinical trials with 3556 participants. One trial compared Radix Sophorae flavescentis with placebo; the remaining 34 trials compared effects of Radix Sophorae flavescentis in addition to a co-intervention versus the same co-intervention. The included trials assessed heterogenous forms and ways of administering Radix Sophorae flavescentis (e.g. oral capsules, oral tablets, intravenous infusion, intramuscular injection, acupoint (a specifically chosen site of acupuncture) injection) with treatment duration of 1 to 24 months. Two of the trials included children up to 14 years old. Participants in two trials had cirrhosis in addition to chronic hepatitis B. All trials were assessed at high risk of bias, and certainty of the evidence for all outcomes was very low.Only one of the 35 trials assessed mortality; no deaths occurred. Ten trials assessed serious adverse events; no serious adverse events occurred. None of the trials reported health-related quality of life, hepatitis B-related mortality, or morbidity. Adverse events considered 'not to be serious' was an outcome in 19 trials; nine of these trials had zero events in both groups. Radix Sophorae flavescentis versus placebo or no intervention showed no difference in effects on adverse events considered 'not to be serious' (RR 1.10, 95% CI 0.76 to 1.59; I² = 49%; 10 trials, 1050 participants). Radix Sophorae flavescentis showed a reduction in the proportion of participants with detectable HBV-DNA (RR 0.61, 95% CI 0.55 to 0.68; I² = 56%; 29 trials, 2914 participants) and in the proportion of participants with detectable HBeAg (hepatitis B e-antigen) (RR 0.71, 95% CI 0.66 to 0.76; I² = 19%; 20 trials, 2129 participants).Seven of the 35 randomised clinical trials received academic funding from government or hospital. Four trials received no funding. The remaining 24 trials provided no information on funding.Additionally, 432 trials lacked the methodological information needed to ensure inclusion of these trials in our review. AUTHORS' CONCLUSIONS: The included trials lacked data on health-related quality of life, hepatitis B-related mortality, and hepatitis B-related morbidity. The effects of Radix Sophorae flavescentis on all-cause mortality and on the proportion of participants with serious adverse events and adverse events considered 'not to be serious' remain unclear. We advise caution in interpreting results showing that Radix Sophorae flavescentis reduced the proportion of people with detectable HBV-DNA and detectable HBeAg because the trials reporting on these outcomes are at high risk of bias and both outcomes are non-validated surrogate outcomes. We were unable to obtain information on the design and conduct of a large number of trials; therefore, we were deterred from including them in our review. Undisclosed funding may influence trial results and may lead to poor trial design. Given the wide usage of Radix Sophorae flavescentis, we need large, unbiased, high-quality placebo-controlled randomised trials in which patient-centred outcomes are assessed.

Evidence-based practice within nutrition: what are the barriers for improving the evidence and how can they be dealt with?

BACKGROUND: Evidence-based clinical research poses special barriers in the field of nutrition. The present review summarises the main barriers to research in the field of nutrition that are not common to all randomised clinical trials or trials on rare diseases and highlights opportunities for improvements. METHODS: Systematic academic literature searches and internal European Clinical Research Infrastructure Network (ECRIN) communications during face-to-face meetings and telephone conferences from 2013 to 2017 within the context of the ECRIN Integrating Activity (ECRIN-IA) project. RESULTS: Many nutrients occur in multiple forms that differ in biological activity, and several factors can alter their bioavailability which raises barriers to their assessment. These include specific difficulties with blinding procedures, with assessments of dietary intake, and with selecting appropriate outcomes as patient-centred outcomes may occur decennia into the future. The methodologies and regulations for drug trials are, however, applicable to nutrition trials. CONCLUSIONS: Research on clinical nutrition should start by collecting clinical data systematically in databases and registries. Measurable patient-centred outcomes and appropriate study designs are needed. International cooperation and multistakeholder engagement are key for success.

Barriers to the conduct of randomised clinical trials within all disease areas.

BACKGROUND: Randomised clinical trials are key to advancing medical knowledge and to enhancing patient care, but major barriers to their conduct exist. The present paper presents some of these barriers. METHODS: We performed systematic literature searches and internal European Clinical Research Infrastructure Network (ECRIN) communications during face-to-face meetings and telephone conferences from 2013 to 2017 within the context of the ECRIN Integrating Activity (ECRIN-IA) project. RESULTS: The following barriers to randomised clinical trials were identified: inadequate knowledge of clinical research and trial methodology; lack of funding; excessive monitoring; restrictive privacy law and lack of transparency; complex regulatory requirements; and inadequate infrastructures. There is a need for more pragmatic randomised clinical trials conducted with low risks of systematic and random errors, and multinational cooperation is essential. CONCLUSIONS: The present paper presents major barriers to randomised clinical trials. It also underlines the value of using a pan-European-distributed infrastructure to help investigators overcome barriers for multi-country trials in any disease area.