Nonregistration, discontinuation, and nonpublication of randomized trials: A repeated metaresearch analysis

BACKGROUND We previously found that 25% of 1,017 randomized clinical trials (RCTs) approved between 2000 and 2003 were discontinued prematurely, and 44% remained unpublished at a median of 12 years follow-up. We aimed to assess a decade later (1) whether rates of completion and publication have increased; (2) the extent to which nonpublished RCTs can be identified in trial registries; and (3) the association between reporting quality of protocols and premature discontinuation or nonpublication of RCTs. METHODS AND FINDINGS We included 326 RCT protocols approved in 2012 by research ethics committees in Switzerland, the United Kingdom, Germany, and Canada in this metaresearch study. Pilot, feasibility, and phase 1 studies were excluded. We extracted trial characteristics from each study protocol and systematically searched for corresponding trial registration (if not reported in the protocol) and full text publications until February 2022. For trial registrations, we searched the (i) World Health Organization: International Clinical Trial Registry Platform (ICTRP); (ii) US National Library of Medicine (ClinicalTrials.gov); (iii) European Union Drug Regulating Authorities Clinical Trials Database (EUCTR); (iv) ISRCTN registry; and (v) Google. For full text publications, we searched PubMed, Google Scholar, and Scopus. We recorded whether RCTs were registered, discontinued (including reason for discontinuation), and published. The reporting quality of RCT protocols was assessed with the 33-item SPIRIT checklist. We used multivariable logistic regression to examine the association between the independent variables protocol reporting quality, planned sample size, type of control (placebo versus other), reporting of any recruitment projection, single-center versus multicenter trials, and industry versus investigator sponsoring, with the 2 dependent variables: (1) publication of RCT results; and (2) trial discontinuation due to poor recruitment. Of the 326 included trials, 19 (6%) were unregistered. Ninety-eight trials (30%) were discontinued prematurely, most often due to poor recruitment (37%; 36/98). One in 5 trials (21%; 70/326) remained unpublished at 10 years follow-up, and 21% of unpublished trials (15/70) were unregistered. Twenty-three of 147 investigator-sponsored trials (16%) reported their results in a trial registry in contrast to 150 of 179 industry-sponsored trials (84%). The median proportion of reported SPIRIT items in included RCT protocols was 69% (interquartile range 61% to 77%). We found no variables associated with trial discontinuation; however, lower reporting quality of trial protocols was associated with nonpublication (odds ratio, 0.71 for each 10% increment in the proportion of SPIRIT items met; 95% confidence interval, 0.55 to 0.92; p = 0.009). Study limitations include that the moderate sample size may have limited the ability of our regression models to identify significant associations. CONCLUSIONS We have observed that rates of premature trial discontinuation have not changed in the past decade. Nonpublication of RCTs has declined but remains common; 21% of unpublished trials could not be identified in registries. Only 16% of investigator-sponsored trials reported results in a trial registry. Higher reporting quality of RCT protocols was associated with publication of results. Further efforts from all stakeholders are needed to improve efficiency and transparency of clinical research

Effect of Anti-Inflammatory Diets on Pain in Rheumatoid Arthritis: A Systematic Review and Meta-Analysis

Various nutritional therapies have been proposed in rheumatoid arthritis, particularly diets rich in ω-3 fatty acids, which may lead to eicosanoid reduction. Our aim was to investigate the effect of potentially anti-inflammatory diets (Mediterranean, vegetarian, vegan, ketogenic) on pain. The primary outcome was pain on a 10 cm visual analogue scale. Secondary outcomes were C-reactive protein levels, erythrocyte sedimentation rate, health assessment questionnaire, disease activity score 28, tender/swollen joint counts, weight, and body mass index. We searched MEDLINE (OVID), Embase (Elsevier), and CINAHL for studies published from database inception to 12 November 2021. Two authors independently assessed studies for inclusion, extracted study data, and assessed the risk of bias. We performed a meta-analysis with all eligible randomized controlled trials using RevMan 5. We used mean differences or standardized mean differences and the inverse variance method of pooling using a random-effects model. The search retrieved 564 unique publications, of which we included 12 in the systematic review and 7 in the meta-analysis. All studies had a high risk of bias and the evidence was very low. The main conclusion is that anti-inflammatory diets resulted in significantly lower pain than ordinary diets (−9.22 mm; 95% CI −14.15 to −4.29; p = 0.0002; 7 RCTs, 326 participants)

Treatment for gastrointestinal and pancreatic neuroendocrine tumours: a network meta-analysis [protocol].

BACKGROUND Several available therapies for neuroendocrine tumours (NETs) have demonstrated efficacy in randomised controlled trials. However, translation of these results into improved care faces several challenges, as a direct comparison of the most pertinent therapies is incomplete. OBJECTIVES To evaluate the safety and efficacy of therapies for NETs, to guide clinical decision-making, and to provide estimates of relative efficiency of the different treatment options (including placebo) and rank the treatments according to their efficiency based on a network meta-analysis. SEARCH METHODS We identified studies through systematic searches of the following bibliographic databases: the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library; MEDLINE (Ovid); and Embase from January 1947 to December 2020. In addition, we checked trial registries for ongoing or unpublished eligible trials and manually searched for abstracts from scientific and clinical meetings. SELECTION CRITERIA We evaluated randomised controlled trials (RCTs) comparing two or more therapies in people with NETs (primarily gastrointestinal and pancreatic). DATA COLLECTION AND ANALYSIS Two review authors independently selected studies and extracted data to a pre-designed data extraction form. Multi-arm studies were included in the network meta-analysis using the R-package netmeta. We separately analysed two different outcomes (disease control and progression-free survival) and two types of NET (gastrointestinal and pancreatic NET) in four network meta-analyses. A frequentist approach was used to compare the efficacy of therapies. MAIN RESULTS We identified 55 studies in 90 records in the qualitative analysis, reporting 39 primary RCTs and 16 subgroup analyses. We included 22 RCTs, with 4299 participants, that reported disease control and/or progression-free survival in the network meta-analysis. Precision-of-treatment estimates and estimated heterogeneity were limited, although the risk of bias was predominantly low. The network meta-analysis of progression-free survival found nine therapies for pancreatic NETs: everolimus (hazard ratio [HR], 0.36 [95% CI, 0.28 to 0.46]), interferon plus somatostatin analogue (HR, 0.34 [95% CI, 0.14 to 0.80]), everolimus plus somatostatin analogue (HR, 0.38 [95% CI, 0.26 to 0.57]), bevacizumab plus somatostatin analogue (HR, 0.36 [95% CI, 0.15 to 0.89]), interferon (HR, 0.41 [95% CI, 0.18 to 0.94]), sunitinib (HR, 0.42 [95% CI, 0.26 to 0.67]), everolimus plus bevacizumab plus somatostatin analogue (HR, 0.48 [95% CI, 0.28 to 0.83]), surufatinib (HR, 0.49 [95% CI, 0.32 to 0.76]), and somatostatin analogue (HR, 0.51 [95% CI, 0.34 to 0.77]); and six therapies for gastrointestinal NETs: 177-Lu-DOTATATE plus somatostatin analogue (HR, 0.07 [95% CI, 0.02 to 0.26]), everolimus plus somatostatin analogue (HR, 0.12 [95%CI, 0.03 to 0.54]), bevacizumab plus somatostatin analogue (HR, 0.18 [95% CI, 0.04 to 0.94]), interferon plus somatostatin analogue (HR, 0.23 [95% CI, 0.06 to 0.93]), surufatinib (HR, 0.33 [95%CI, 0.12 to 0.88]), and somatostatin analogue (HR, 0.34 [95% CI, 0.16 to 0.76]), with higher efficacy than placebo. Besides everolimus for pancreatic NETs, the results suggested an overall superiority of combination therapies, including somatostatin analogues. The results indicate that NET therapies have a broad range of risk for adverse events and effects on quality of life, but these were reported inconsistently. Evidence from this network meta-analysis (and underlying RCTs) does not support any particular therapy (or combinations of therapies) with respect to patient-centred outcomes (e.g. overall survival and quality of life). AUTHORS' CONCLUSIONS The findings from this study suggest that a range of efficient therapies with different safety profiles is available for people with NETs

Cardiovascular effects and safety of long-term colchicine treatment: Cochrane review and meta-analysis

Colchicine is an old anti-inflammatory drug that has shown substantial cardiovascular benefits in recent trials. We systematically reviewed cardiovascular benefits and harms of colchicine in any population and specifically in patients with high cardiovascular risk. We evaluated randomised controlled trials comparing colchicine over at least 6 months versus any control in any adult population. Primary outcomes were all-cause mortality, myocardial infarction and adverse events. Cardiovascular mortality was a secondary outcome. We included 39 trials with 4992 patients. The quality of evidence for mortality outcomes and myocardial infarction was moderate but lower for adverse events. Colchicine had no effect on all-cause mortality (RR 0.94, 95% CI 0.82 to 1.09; I(2)=27%; 30 trials). Cardiovascular mortality was reduced in some but not all meta-analytical models (random-effects RR 0.34, 0.09 to 1.21, I(2)=9%; Peto's OR 0.24, 0.09 to 0.64, I(2)=15%; Mantel-Haenszel fixed-effect RR 0.20, 0.06 to 0.68, I(2)=0%; 7 trials). The risk for myocardial infarction was reduced (RR 0.20, 0.07 to 0.57; 2 trials). There was no effect on total adverse events (RR 1.52, 0.93 to 2.46, I(2)=45%; 11 trials) but gastrointestinal intolerance was increased (RR 1.83, 1.03 to 3.26, I(2)=74%; 11 trials). Reporting of serious adverse events was inconsistent; no event occurred over 824 patient-years (4 trials). Effects in high cardiovascular risk populations were similar (4 trials; 1230 patients). We found no evidence supporting colchicine doses above 1 mg/day. Colchicine may have substantial cardiovascular benefits; however, there is sufficient uncertainty about its benefit and harm to indicate the need for large-scale trials to further evaluate this inexpensive, promising treatment in cardiovascular disease

Colchicine for prevention of cardiovascular events

Colchicine is an anti-inflammatory drug that is used for a wide range of inflammatory diseases. Cardiovascular disease also has an inflammatory component but the effects of colchicine on cardiovascular outcomes remain unclear. Previous safety analyses were restricted to specific patient populations.; To evaluate potential cardiovascular benefits and harms of a continuous long-term treatment with colchicine in any population, and specifically in people with high cardiovascular risk.; We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, ClinicalTrials.gov, WHO International Clinical Trials Registry, citations of key papers, and study references in January 2015. We also contacted investigators to gain unpublished data.; Randomised controlled trials (parallel-group or cluster design or first phases of cross-over studies) comparing colchicine over at least six months versus any control in any adult population.; Primary outcomes were all-cause mortality, myocardial infarction, and adverse events. Secondary outcomes were cardiovascular mortality, stroke, heart failure, non-scheduled hospitalisations, and non-scheduled cardiovascular interventions. We conducted predefined subgroup analyses, in particular for participants with high cardiovascular risk. .; We included 39 randomised parallel-group trials with 4992 participants. Colchicine had no effect on all-cause mortality (RR 0.94, 95% CI 0.82 to 1.09; participants = 4174; studies = 30; I² = 27%; moderate quality of evidence). There is uncertainty surrounding the effect of colchicine in reducing cardiovascular mortality (RR 0.34, 95% CI 0.09 to 1.21, I² = 9%; participants = 1132; studies = 7; moderate quality of evidence). Colchicine reduced the risk for total myocardial infarction (RR 0.20, 95% CI 0.07 to 0.57; participants = 652; studies = 2; moderate quality of evidence). There was no effect on total adverse events (RR 1.52, 95% CI 0.93 to 2.46; participants = 1313; studies = 11; I² = 45%; very low quality of evidence) but gastrointestinal intolerance was increased (RR 1.83, 95% CI 1.03 to 3.26; participants = 1258; studies = 11; I² = 74%; low quality of evidence). Colchicine showed no effect on heart failure (RR 0.62, 95% CI 0.10 to 3.88; participants = 462; studies = 3; I² = 45%; low quality of evidence) and no effect on stroke (RR 0.38, 95% CI 0.09 to 1.70; participants = 874; studies = 3; I² = 45%; low quality of evidence). Reporting of serious adverse events was inconsistent; no event occurred over 824 patient-years (4 trials). Effects on other outcomes were very uncertain. Summary effects of RCTs specifically focusing on participants with high cardiovascular risk were similar (4 trials; 1230 participants).; There is much uncertainty surrounding the benefits and harms of colchicine treatment. Colchicine may have substantial benefits in reducing myocardial infarction in selected high-risk populations but uncertainty about the size of the effect on survival and other cardiovascular outcomes is high, especially in the general population from which most of the studies in our review were drawn. Colchicine is associated with gastrointestinal side effects based on low-quality evidence. More evidence from large-scale randomised trials is needed

Treatment for gastrointestinal and pancreatic neuroendocrine tumours: a network meta-analysis.

BACKGROUND Several available therapies for neuroendocrine tumours (NETs) have demonstrated efficacy in randomised controlled trials. However, translation of these results into improved care faces several challenges, as a direct comparison of the most pertinent therapies is incomplete. OBJECTIVES To evaluate the safety and efficacy of therapies for NETs, to guide clinical decision-making, and to provide estimates of relative efficiency of the different treatment options (including placebo) and rank the treatments according to their efficiency based on a network meta-analysis. SEARCH METHODS We identified studies through systematic searches of the following bibliographic databases: the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library; MEDLINE (Ovid); and Embase from January 1947 to December 2020. In addition, we checked trial registries for ongoing or unpublished eligible trials and manually searched for abstracts from scientific and clinical meetings. SELECTION CRITERIA We evaluated randomised controlled trials (RCTs) comparing two or more therapies in people with NETs (primarily gastrointestinal and pancreatic). DATA COLLECTION AND ANALYSIS Two review authors independently selected studies and extracted data to a pre-designed data extraction form. Multi-arm studies were included in the network meta-analysis using the R-package netmeta. We separately analysed two different outcomes (disease control and progression-free survival) and two types of NET (gastrointestinal and pancreatic NET) in four network meta-analyses. A frequentist approach was used to compare the efficacy of therapies. MAIN RESULTS We identified 55 studies in 90 records in the qualitative analysis, reporting 39 primary RCTs and 16 subgroup analyses. We included 22 RCTs, with 4299 participants, that reported disease control and/or progression-free survival in the network meta-analysis. Precision-of-treatment estimates and estimated heterogeneity were limited, although the risk of bias was predominantly low. The network meta-analysis of progression-free survival found nine therapies for pancreatic NETs: everolimus (hazard ratio [HR], 0.36 [95% CI, 0.28 to 0.46]), interferon plus somatostatin analogue (HR, 0.34 [95% CI, 0.14 to 0.80]), everolimus plus somatostatin analogue (HR, 0.38 [95% CI, 0.26 to 0.57]), bevacizumab plus somatostatin analogue (HR, 0.36 [95% CI, 0.15 to 0.89]), interferon (HR, 0.41 [95% CI, 0.18 to 0.94]), sunitinib (HR, 0.42 [95% CI, 0.26 to 0.67]), everolimus plus bevacizumab plus somatostatin analogue (HR, 0.48 [95% CI, 0.28 to 0.83]), surufatinib (HR, 0.49 [95% CI, 0.32 to 0.76]), and somatostatin analogue (HR, 0.51 [95% CI, 0.34 to 0.77]); and six therapies for gastrointestinal NETs: 177-Lu-DOTATATE plus somatostatin analogue (HR, 0.07 [95% CI, 0.02 to 0.26]), everolimus plus somatostatin analogue (HR, 0.12 [95%CI, 0.03 to 0.54]), bevacizumab plus somatostatin analogue (HR, 0.18 [95% CI, 0.04 to 0.94]), interferon plus somatostatin analogue (HR, 0.23 [95% CI, 0.06 to 0.93]), surufatinib (HR, 0.33 [95%CI, 0.12 to 0.88]), and somatostatin analogue (HR, 0.34 [95% CI, 0.16 to 0.76]), with higher efficacy than placebo. Besides everolimus for pancreatic NETs, the results suggested an overall superiority of combination therapies, including somatostatin analogues. The results indicate that NET therapies have a broad range of risk for adverse events and effects on quality of life, but these were reported inconsistently. Evidence from this network meta-analysis (and underlying RCTs) does not support any particular therapy (or combinations of therapies) with respect to patient-centred outcomes (e.g. overall survival and quality of life). AUTHORS' CONCLUSIONS The findings from this study suggest that a range of efficient therapies with different safety profiles is available for people with NETs

Acetylcholinesterase inhibitors combined with memantine for moderate to severe Alzheimer's disease:A meta-analysis

BACKGROUND: The clinical efficacy and safety of combination therapy with acetylcholinesterase inhibitor (AChEI) and memantine compared to AChEI or memantine alone in patients with Alzheimer's disease is inconclusive. AIMS OF THE STUDY. We conducted a systematic review and meta-analysis of randomised controlled trials (RCTs) comparing the clinical efficacy and safety of combination therapy of AChEI and memantine to monotherapy with either substance in patients with moderate to severe Alzheimer's disease (Mini-Mental State Examination score is &lt;20). METHODS: We systematically searched EMBASE, Medline and CENTRAL until February 2018 for eligible RCTs. We pooled the outcome data using inverse variance weighting models assuming random effects, and assessed the quality of evidence (QoE) according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE). RESULTS: We included nine RCTs (2604 patients). At short-term follow-up (closest to 6 months), combination therapy compared to AChEI monotherapy had a significantly greater effect on cognition than AChEI monotherapy (standardised mean difference [SMD] 0.20, 95% confidence interval [CI] 0.05 to 0.35, 7 RCTs, low QoE) and clinical global impression (SMD -0.15, 95% CI -0.28 to -0.01, 4 RCTs, moderate QoE), but not on activities of daily living (SMD 0.09, 95% CI -0.01 to 0.18, 5 RCTs, moderate QoE) or behavioural and psychological symptoms of dementia (mean difference -3.07, 95% CI -6.53 to 0.38, 6 RCT, low QoE). There was no significant difference in adverse events (relative risk ratio 1.05, 95% CI 0.98 to 1.12, 4 RCTs, low QoE). Evidence for long-term follow-up (= 9 months) or nursing home placement was sparse. Only two studies compared combination therapy with memantine monotherapy. CONCLUSIONS: Combination therapy had statistically significant effects on cognition and clinical global impression. The clinical relevance of these effects is uncertain. The overall QoE was very low. With the current evidence, it remains unclear whether combination therapy adds any benefit. Large pragmatic RCTs with long-term follow-up and focus on functional outcomes, delay in nursing home placement and adverse events are needed.</p

Acetylcholinesterase inhibitors combined with memantine for moderate to severe Alzheimer's disease: a meta-analysis

BACKGROUND The clinical efficacy and safety of combination therapy with acetylcholinesterase inhibitor (AChEI) and memantine compared to AChEI or memantine alone in patients with Alzheimer&rsquo;s disease is inconclusive. AIMS OF THE STUDY We conducted a systematic review and meta-analysis of randomised controlled trials (RCTs) comparing the clinical efficacy and safety of combination therapy of AChEI and memantine to monotherapy with either substance in patients with moderate to severe Alzheimer&#39;s disease (Mini-Mental State Examination score is &lt;20). METHODS We systematically searched EMBASE, Medline and CENTRAL until February 2018 for eligible RCTs. We pooled the outcome data using inverse variance weighting models assuming random effects, and assessed the quality of evidence (QoE) according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE). RESULTS We included nine RCTs (2604 patients). At short-term follow-up (closest to 6 months), combination therapy compared to AChEI monotherapy had a significantly greater effect on cognition than AChEI monotherapy (standardised mean difference [SMD] 0.20, 95% confidence interval [CI] 0.05 to 0.35, 7 RCTs, low QoE) and clinical global impression (SMD &minus;0.15, 95% CI &minus;0.28 to &minus;0.01, 4 RCTs, moderate QoE), but not on activities of daily living (SMD 0.09, 95% CI &minus;0.01 to 0.18, 5 RCTs, moderate QoE) or behavioural and psychological symptoms of dementia (mean difference &minus;3.07, 95% CI &minus;6.53 to 0.38, 6 RCT, low QoE). There was no significant difference in adverse events (relative risk ratio 1.05, 95% CI 0.98 to 1.12, 4 RCTs, low QoE). Evidence for long-term follow-up (&ge; 9 months) or nursing home placement was sparse. Only two studies compared combination therapy with memantine monotherapy. CONCLUSIONS Combination therapy had statistically significant effects on cognition and clinical global impression. The clinical relevance of these effects is uncertain. The overall QoE was very low. With the current evidence, it remains unclear whether combination therapy adds any benefit. Large pragmatic RCTs with long-term follow-up and focus on functional outcomes, delay in nursing home placement and adverse events are needed. &nbsp