Gresham's Law of Evidence

PEDIATRICS ◽  
1978 ◽  
Vol 61 (3) ◽  
pp. 507-507
Author(s):  
Keyword(s):  
Clinical Trials ◽  
Randomized Trials ◽  
Randomized Clinical Trials ◽  
Medical Treatments ◽  
The Past ◽  
Law Of Evidence

A recent review1 of the epidemiology of randomized clinical trials indicates very slow acceptance of this approach to evaluation of new medical treatments. If the proportion of randomized trials among therapeutic studies in gastroenterology continues to increase at the rate observed over the past decade, the reviewers estimate that the format will have taken over completely by the year 2010 provided the increase is exponential, and in about 700 years if it is linear. I write to suggest that a law, similar to Gresham's Law—cheap money will drive out dear money—operates in these matters.

On the Evaluation of Treatments for Narcotics Addiction

1979 ◽  
Vol 9 (2) ◽  
pp. 205-211 ◽  
Author(s):  
Vincent P. Dole ◽  
Burton Singer
Keyword(s):  
Clinical Trials ◽  
Randomized Trial ◽  
Observational Data ◽  
Chronic Diseases ◽  
Drug Addiction ◽  
Randomized Trials ◽  
Randomized Clinical Trials ◽  
The Other ◽  
Domain Of Applicability

This study is concerned with the domain of applicability of randomized clinical trials. For evaluation of well-defined treatments of acute diseases over limited periods of time, the randomized trial technique is unquestionably the best. However, in the field of chronic diseases (as illustrated by drug addiction) the physician's responsibility extends over periods of years, and his judgements involve consideration of many contingent factors which vary in the course of the disease. In this domain, randomized clinical trials, however ambitious in design, give only partial guidance. Observational data therefore must be used if treatment is to be optimized for individual patients. Two randomized trials in the treatment of narcotics addiction — one testing methadone and the other naltrexone — are reviewed, with comments on their conclusions and limitations.

scholarly journals Bias and unclear outcomes in clinical trials of diabetic retinopathy: a cross-sectional analysis of literature

2021 ◽  
Vol 3 ◽  
Author(s):  
Vania Mozetic ◽  
Valéria Mozetic de Barros ◽  
Lucas Denadai ◽  
Matheus Ferreira Santos da Cruz ◽  
Natasha Ferreira Santos da Cruz ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Diabetic Retinopathy ◽  
Adverse Events ◽  
Publication Bias ◽  
Randomized Clinical Trials ◽  
Cross Sectional ◽  
Know How ◽  
The Past ◽  
Sectional Analysis ◽  
Subjective Outcomes

BACKGROUND: Clinical trials are well-designed papers that aim to answer questions in the real world. However, sometimes they present missing, dubious and unclear outcomes that make it difficult to apply in practice. OBJECTIVE: The objective of this work is to evaluate the way and the frequency with which the outcomes in randomized clinical trials of intervention in diabetic retinopathy can be presented in an unclear way to readers. Make an analysis of how these dubious presentations can lead to misinterpretations, why this happens and how they can be remedied. METHODS AND MATERIALS: We conducted a search for RCT about DR intervention in PubMed published over the past five years. RESULTS: Seventy RCT were included, 27 in peripheral diabetic retinopathy (PDR) and 43 in diabetic macular edema (DME). In the DME group we found 25.6% reporting and publication bias; 34.9% subjective outcomes, 44.1% presented a lack of presentation of the baseline and 51.1% underreporting adverse events. In the PDR group we found 29.6% reporting and publication bias; 44.4% subjective outcomes, 14.8% presented a lack of presentation of the baseline and 62.9% underreporting adverse events. CONCLUSION: In addition to the result bias, we found other forms of publication of unclear outcomes in RCT on DR. Most of them occurred due to disrespect for CONSORT parameters. The reader must be attentive to recognize them and know how they can influence the interpretation of the data.

Carotid artery stenting: A systematic review of randomized clinical trials

VASA ◽  
2009 ◽  
Vol 38 (4) ◽  
pp. 281-291 ◽  
Author(s):  
Knur
Keyword(s):  
Clinical Trials ◽  
High Risk ◽  
Carotid Artery ◽  
Carotid Artery Stenting ◽  
Randomized Trials ◽  
Randomized Clinical Trials ◽  
Low Risk ◽  
Carotid Surgery ◽  
Risk Patients ◽  
Carotid Occlusive Disease

Carotid occlusive disease is responsible for a significant proportion of major adverse cardiovascular events (death, stroke, myocardial infarction). Effective prevention by means of revascularization is a sufficient treatment, if performed at a center with an acceptably low procedural complication rate. Carotid surgery is the currently accepted standard of treatment for revascularization of extra cranial carotid occlusive disease. This has been validated by randomized clinical trials that have demonstrated its efficacy over best medical therapy. However, less invasive protected carotid artery stenting (CAS) has emerged as a potential therapeutic alternative to carotid endarterectomy (CEA) for the treatment of carotid atherosclerotic disease. Over the past decade several clinical trials have compared endovascular with surgical treatment. The Stenting and Angioplasty with Protection in Patients at High Risk for Endarterectomy (SAPPHIRE) trial favored stenting over surgery in high-risk patients. The effectiveness of endovascular treatment in low-risk patients and patients with asymptomatic stenoses at preventing of stroke is still uncertain. Carotid artery stenting with an embolic protection device cannot be considered a scientifically sound and evidence-based alternative to carotid surgery in low-risk and asymptomatic patients until we have the results of further randomized trials. This overview presents the currently available data from randomized trials.

scholarly journals Incidental genetic findings in randomized clinical trials: recommendations from the Genomics and Randomized Trials Network (GARNET)

10.1186/gm411 ◽  
2013 ◽  
Vol 5 (1) ◽  
pp. 7 ◽  
Author(s):  
Ebony B Bookman ◽  
Corina Din-Lovinescu ◽  
Bradford B Worrall ◽  
Teri A Manolio ◽  
Siiri N Bennett ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Randomized Trials ◽  
Randomized Clinical Trials

scholarly journals Variation in Outcome Measures in Hip and Knee Arthroplasty Clinical Trials: A Proposed Approach to Achieving Consensus

2009 ◽  
Vol 36 (9) ◽  
pp. 2050-2056 ◽  
Author(s):  
DANIEL L. RIDDLE ◽  
PAUL W. STRATFORD ◽  
JASVINDER A. SINGH ◽  
C. VIBEKE STRAND
Keyword(s):  
Clinical Trials ◽  
Outcome Measures ◽  
Knee Arthroplasty ◽  
Randomized Trials ◽  
Survey Design ◽  
Hip Osteoarthritis ◽  
Optimal Outcome ◽  
The Past ◽  
Hip And Knee Arthroplasty ◽  
Knee And Hip Arthroplasty

OMERACT began work over a decade ago on a consensus effort to identify optimal outcome measures for knee and hip osteoarthritis clinical trials. Recent evidence indicates extensive variation in outcome measures used in clinical trials of knee and hip arthroplasty published since 2000. This heterogeneity leads to confusion, not only for conducting systematic reviews but also for applying evidence to clinical practice. Given the extensive psychometric research conducted in the past 2 decades, the timing seems ideal to design and implement a study to develop consensus on optimal outcome measures for hip and knee arthroplasty trials. We describe a Delphi survey design and an approach for synthesizing the extensive psychometric literature on the outcome measures used in hip and knee arthroplasty trials. Plans for dissemination of the findings are also discussed. This proposed study could have an important influence on the design and reporting of future randomized trials of knee arthroplasty.

scholarly journals Contrast Media: Are There Differences in Nephrotoxicity among Contrast Media?

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Richard Solomon
Keyword(s):  
Clinical Trials ◽  
Contrast Media ◽  
Contrast Agents ◽  
Filtration Rate ◽  
Randomized Clinical Trials ◽  
The Past ◽  
Iodinated Contrast ◽  
Using Data ◽  
The Relationship ◽  
Iodinated Contrast Agents

Iodinated contrast agents are usually classified based upon their osmolality—high, low, and isosmolar. Iodinated contrast agents are also nephrotoxic in some but not all patients resulting in loss of glomerular filtration rate. Over the past 30 years, nephrotoxicity has been linked to osmolality although the precise mechanism underlying such a link has been elusive. Improvements in our understanding of the pathogenesis of nephrotoxicity and prospective randomized clinical trials have attempted to further explore the relationship between osmolality and nephrotoxicity. In this review, the basis for our current understanding that there are little if any differences in nephrotoxic potential between low and isosmolar contrast media will be detailed using data from clinical studies.

Infections in cancer patients treated with immune checkpoint inhibitors: Data from randomized trials.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 2637-2637
Author(s):  
Cinzia Solinas ◽  
Anna Maria Morelli ◽  
Andrea Luciani ◽  
Antonio Ghidini ◽  
Fausto Petrelli
Keyword(s):  
Clinical Trials ◽  
Cancer Patients ◽  
Solid Tumors ◽  
Immune Checkpoint ◽  
Immune Checkpoint Inhibitors ◽  
Randomized Trials ◽  
Randomized Clinical Trials ◽  
Checkpoint Inhibitors ◽  
Cochrane Library ◽  
And Control

2637 Background: Febrile neutropenia and infections are well studied complications of chemotherapy (CT) and some targeted agents employed in oncology. Less is known about the risk of infection associated with the use of immune checkpoint inhibitors (ICIs) in cancer patients. The present systematic review and meta-analysis was performed to address this question in patients diagnosed with solid tumors enrolled in randomized trials employing ICIs as experimental treatment. Methods: The Cochrane Library, EMBASE, and Pubmed databases were searched from inception through December 1st, 2020. Randomized clinical trials comparing any ICI alone, with CT, or with other agents vs CT, placebo, or other agents in patients with solid tumors were included. Two independent reviewers used a standardized data extraction and quality assessment form. Discordant cases were discussed with a third independent investigator. The following information was extracted: baseline study characteristics, including the primary tumor, author, year of publication, type of trial, type of disease, and the type of therapy (experimental and control arms); and the incidence of any-grade (grades [G] 1–5), low-grade (G1–2), and high-grade (G3–4), fatal event (G5) infections, and type of event. Random or fixed-effect models were used according to the statistical heterogeneity. Results: 36 randomized clinical trials were deemed eligible. The total population reached 21451 patients. In the pooled analysis, the use of ICIs was associated with a similar risk of all-grade infections (relative risk, RR = 1.02; 95% CI 0.84–1.24; P = 0.85) compared to non-ICI treatments (G1-5 events: 9.6 vs. 8.3%). When the ICIs alone arms were compared to CT, the experimental arms were associated with a 42% less risk of all-grade infections (RR = 0.58, 95% CI 0.4–0.85; P = 0.01; N = 18 studies). Compared to CT, the combination of ICIs and CT increased the risk of all-grade infections (RR = 1.37, 95% CI 1.23–1.53; P < 0.01; N = 13 studies) and severe infections (RR = 1.52, 95% CI 1.17–1.96; P < 0.01; N = 12 studies). Fatal infections were similar in the experimental and control arms (0.5%). Conclusions: In patients with advanced solid tumors, when ICIs were administered with CT, the risk of all-grade and G3-5 infections was significantly increased. Compared to CT alone, ICIs were safer and their use should be recommended for frail patients. Further studies are required to identify high-risk patients and evaluate the need for CT dose reduction or prophylactic myeloid growth factors use.

scholarly journals Systematic Review of Randomized Clinical Trials on Safety and Efficacy of Pharmacological and Nonpharmacological Treatments for Retinitis Pigmentosa

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Marta Sacchetti ◽  
Flavio Mantelli ◽  
Daniela Merlo ◽  
Alessandro Lambiase
Keyword(s):  
Systematic Review ◽  
Clinical Trials ◽  
Retinitis Pigmentosa ◽  
Randomized Clinical Trials ◽  
Clinical Results ◽  
Medical Treatments ◽  
Safety And Efficacy ◽  
Medical Interventions ◽  
Nonpharmacological Treatments

Aims.Several treatments have been proposed to slow down progression of Retinitis pigmentosa (RP), a hereditary retinal degenerative condition leading to severe visual impairment. The aim of this study is to systematically review data from randomized clinical trials (RCTs) evaluating safety and efficacy of medical interventions for the treatment of RP.Methods.Randomized clinical trials on medical treatments for syndromic and nonsyndromic RP published up to December 2014 were included in the review. Visual acuity, visual field, electroretinogram, and adverse events were used as outcome measures.Results.The 19 RCTs included in this systematic review included trials on hyperbaric oxygen delivery, topical brimonidine tartrate, vitamins, docosahexaenoic acid, gangliosides, lutein, oral nilvadipine, ciliary neurotrophic factor, and valproic acid. All treatments proved safe but did not show significant benefit on visual function. Long term supplementation with vitamin A showed a significantly slower decline rate in electroretinogram amplitude.Conclusions.Although all medical treatments for RP appear safe, evidence emerging from RCTs is limited since they do not present comparable results suitable for quantitative statistical analysis. The limited number of RCTs, the poor clinical results, and the heterogeneity among studies negatively influence the strength of recommendations for the long term management of RP patients.

Evaluating Mortality with Erythropoietic Stimulating Agents (ESAs) in the Nephrology Setting: The Distinction between Evaluating Trials That Measure Survival as a Primary or Secondary Efficacy Endpoint Versus a Safety Endpoint.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 962-962
Author(s):  
Sara E. Barnato ◽  
Charles L. Bennett ◽  
Kathleen Elverman ◽  
Dennis P. West ◽  
Mark Courtney
Keyword(s):  
Clinical Trials ◽  
Relative Risk ◽  
Randomized Trials ◽  
Randomized Clinical Trials ◽  
Outcome Measure ◽  
Meta Analysis ◽  
Safety Measure ◽  
Significant Safety ◽  
Randomized Controlled ◽  
Efficacy Outcome

Abstract Background: At ASCO 2007, we reported increased mortality risks when ESAs are administered to anemic cancer patients who are receiving chemotherapy when target hemoglobin levels are beyond the correction of anemia. In February 2007, a meta-analysis of nine randomized clinical trials with 5,143 patients published in the Lancet [vol 369; 381–88] identified a statistically significant risk of all cause mortality (relative risk (RR) of 1.17, 95% confidence interval (CI) 1.01, 1.35) when anemic patients with chronic kidney disease received ESAs targeted to higher hemoglobin concentrations (120–150 g/L). A recent report from the RADAR (Research against Adverse Drug Reactions) group raises concern that survival analyses might differ depending on whether survival was evaluated as a measure of efficacy versus a measure of safety. Herein, we re-analyze the data by evaluating randomized clinical trials according to whether or not survival was prospectively included as a primary or secondary efficacy outcome. Methods: Risks of death in randomized controlled clinical trials included in the Lancet meta-analysis were evaluated. We classified those studies based on their mortality outcomes, either as an efficacy outcome or as a safety outcome. Effect estimates for RR and 95% CI were derived from Stata (version 9.1, College Station, TX), calculated with random-effects models and pooled by use of the Dersimonian and Laird method. Results: In studies where survival was measured as an efficacy endpoint, the relative risk of mortality with ESAs targeted to higher hemoglobin levels was 1.27 (1.08, 1.49), a number greater than the relative risk reported in the Lancet meta-analysis. Conclusions: Randomized controlled trials should be included in meta-analyses that evaluate harms only if the relevant safety measure is prospectively included as a primary or secondary efficacy outcome measure in the study protocol. When survival was included as part of the efficacy analysis, a statistically significant safety signal was present. Randomized trials that included harms as a measure of safety did not present a statistically significant safety signal. Including randomized trials that include harms as a safety measure introduce noise and can mask safety signals. Studies: Events: RR (95% CI) Survival included as a primary or secondary efficacy outcome measure: High vs Low Hb Target: Besarab 1998 (n=1233) 183/618 vs 150/615 1.21 (1.01, 1.46) Gouva 2004 (n=88) 4/43 vs 3/45 1.40 (0.33, 5.87) Drueke 2006 (n=602) 31/300 vs 21/302 1.49 (0.87, 2.53) Singh 2006 (n=1432) 52/715 vs 36/717 1.45 (0.96, 2.19) Subtotal (n=3355) 270/1676 vs 210/1679 1.27 (1.08, 1.49) Survival included only as a safety measure: High vs Low Hb Target: Foley 2000 (n=146) 4/73 vs 3/73 1.33 (0.31, 5.75) Furuland 2003 (n=416) 29/216 vs 27/200 0.99 (0.61, 1.62) Roger 2005 (n=154) 0/75 vs 0/79 not estimable Levin 2005 (n=152) 1/74 vs 3/78 0.35 (0.04, 3.30) Parfrey 2005 (n=696) 12/396 vs 20/300 0.45 (0.23, 0.92) Rossert 2006 (n=390) 1/195 vs 6/195 0.17 (0.02, 1.37) Subtotal (n=1954) 47/1029 vs 59/925 0.67 (0.37, 1.19)

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