The impact of data errors on the outcome of randomized clinical trials

2017 ◽  
Vol 14 (5) ◽  
pp. 499-506 ◽  
Author(s):  
Marc Buyse ◽  
Pierre Squifflet ◽  
Elisabeth Coart ◽  
Emmanuel Quinaux ◽  
Cornelis JA Punt ◽  
...  

Background/aims Considerable human and financial resources are typically spent to ensure that data collected for clinical trials are free from errors. We investigated the impact of random and systematic errors on the outcome of randomized clinical trials. Methods We used individual patient data relating to response endpoints of interest in two published randomized clinical trials, one in ophthalmology and one in oncology. These randomized clinical trials enrolled 1186 patients with age-related macular degeneration and 736 patients with metastatic colorectal cancer. The ophthalmology trial tested the benefit of pegaptanib for the treatment of age-related macular degeneration and identified a statistically significant treatment benefit, whereas the oncology trial assessed the benefit of adding cetuximab to a regimen of capecitabine, oxaliplatin, and bevacizumab for the treatment of metastatic colorectal cancer and failed to identify a statistically significant treatment difference. We simulated trial results by adding errors that were independent of the treatment group (random errors) and errors that favored one of the treatment groups (systematic errors). We added such errors to the data for the response endpoint of interest for increasing proportions of randomly selected patients. Results Random errors added to up to 50% of the cases produced only slightly inflated variance in the estimated treatment effect of both trials, with no qualitative change in the p-value. In contrast, systematic errors produced bias even for very small proportions of patients with added errors. Conclusion A substantial amount of random errors is required before appreciable effects on the outcome of randomized clinical trials are noted. In contrast, even a small amount of systematic errors can severely bias the estimated treatment effects. Therefore, resources devoted to randomized clinical trials should be spent primarily on minimizing sources of systematic errors which can bias the analyses, rather than on random errors which result only in a small loss in power.

2020 ◽  
Vol 96 (2) ◽  
pp. 3-6
Author(s):  
M.C. Maccarone ◽  
G. Magro ◽  
U. Solimene ◽  
S. Masiero

Chronic Musculoskeletal Disorders (MSDs) are age-related conditions, linked to functional impairment and decreased quality of life (QoL). As a result of the increased life expectancy in Europe, great attention has been focused on investigating the impact of these diseases on QoL. Thermal environment is a suitable place for providing interventions (mud therapy, bath, exercise, etc.) for chronic MSD patients. Our narrative review aims to assess if Spa therapy may improve QoL in patients with chronic MSDs. We searched randomized clinical trials and clinical trials screening PubMed and Google Scholar databases from 2016 up to March 2020. We included 14 trials testing Spa therapy interventions concerning osteoarthritis, rheumatoid arthritis, chronic shoulder pain and fibromyalgia. In conclusion, even though limitations must be considered, evidence shows that Spa therapy, especially in combination with rehabilitation approach, can significantly improve QoL of patients with chronic MSDs.


2019 ◽  
Vol 2 (9) ◽  
pp. e1911750
Author(s):  
Tomasz Burzykowski ◽  
Elisabeth Coart ◽  
Everardo D. Saad ◽  
Qian Shi ◽  
Dirkje W. Sommeijer ◽  
...  

2015 ◽  
Vol 33 (3_suppl) ◽  
pp. 673-673
Author(s):  
Ziwei Wang ◽  
Lindsay Hwang ◽  
James Don Murphy

673 Background: Randomized clinical trials play a central role in clinical research though only a small fraction of patients partake in clinical studies. Questions thus arise regarding the generalizability of clinical trial results to the remainder of the population. This study evaluated whether patient survival from randomized clinical trials in metastatic colorectal cancer reflects real world outcomes. Methods: A Pubmed search was used to identify randomized phase III clinical trials of first-line treatment for metastatic colorectal cancer published between 2005 and 2010. We excluded secondary or pooled analyses, second-line treatments, non-metastatic patients, non-English language, and non-randomized studies. Thirty-one clinical trials met these criteria, comprised of 79 distinct clinical trial arms. Overall survival among clinical trial patients was compared to metastatic colorectal cancer patients within the Surveillance, Epidemiology, and End Results (SEER) program. Within SEER, we restricted the analysis time-period and age of patients to match the enrollment period and age of patients within each individual clinical trial. Results: The clinical trials enrolled a total of 16,614 patients. Among all clinical trial arms the median survival ranged from 6.7-62 months, 1-year survival ranged from 30-97%, and 2-year survival ranged from 6-88%. Compared to SEER, the median survival was higher in 95% of the individual clinical trial arms by an average of 5.4 months (p<0.0001). The 1-year survival was higher in 94% of the clinical trial arms by an average of 16.7% (p<0.0001). The 2-year survival was higher in 71% of the clinical trial arms by an average of 7.2% (p<0.0001). Conclusions: This study found substantially improved survival among clinical trial participants compared to patients in the SEER database suggesting that survival estimates from clinical trials may not generalize to the “real world.” Potential patient factors such as differences in underlying comorbidity, performance status, disease burden, as well as variation in treatment could not be addressed in this study, though these factors likely explain some of the observed survival differences.


2017 ◽  
Vol 35 (17) ◽  
pp. 1929-1937 ◽  
Author(s):  
Lindsay A. Renfro ◽  
Richard M. Goldberg ◽  
Axel Grothey ◽  
Alberto Sobrero ◽  
Richard Adams ◽  
...  

Purpose Factors contributing to early mortality after initiation of treatment of metastatic colorectal cancer are poorly understood. Materials and Methods Data from 22,654 patients enrolled in 28 randomized phase III trials contained in the ARCAD (Aide et Recherche en Cancérologie Digestive) database were pooled. Multivariable logistic regression models for 30-, 60-, and 90-day mortality were constructed, including clinically and statistically significant patient and disease factors and interaction terms. A calculator (nomogram) for 90-day mortality was developed and validated internally using bootstrapping methods and externally using a 10% random holdout sample from each trial. The impact of early progression on the likelihood of survival to 90 days was examined with time-dependent Cox proportional hazards models. Results Mortality rates were 1.4% at 30 days, 3.4% at 60 days, and 5.5% at 90 days. Among baseline factors, advanced age, lower body mass index, poorer performance status, increased number of metastatic sites, BRAF mutant status, and several laboratory parameters were associated with increased likelihood of early mortality. A multivariable model for 90-day mortality showed strong internal discrimination (C-index, 0.77) and good calibration across risk groups as well as accurate predictions in the external validation set, both overall and within patient subgroups. Conclusion A validated clinical nomogram has been developed to quantify the risk of early death for individual patients during initial treatment of metastatic colorectal cancer. This tool may be used for patient eligibility assessment or risk stratification in future clinical trials and to identify patients requiring more or less aggressive therapy and additional supportive measures during and after treatment.


2015 ◽  
Vol 33 (3_suppl) ◽  
pp. 692-692
Author(s):  
Sunil Parimi ◽  
Soundouss Raissouni ◽  
Yongtao Lin ◽  
Jose Gerard Monzon ◽  
Patricia A. Tang ◽  
...  

692 Background: Increasing use of subsequent lines of therapy and crossover in phase III randomized clinical trials (P3 RCTs) has shifted how we perceive the effectiveness of treatments for metastatic colorectal cancer (mCRC). This study aims to characterize the evolution of P3 RCTs in mCRC with respect to clinical trial design and result interpretation. Methods: Abstracts of P3 RCTs of systemic therapy for mCRC conducted between 1980 and 2014 were identified by searching PubMed, Medline, and ASCO abstracts. Data regarding trial design, agent(s) investigated, primary endpoint, secondary endpoint(s), primary endpoint significance and interpretation of the study results (conclusions) were extracted. Results: A total of 422 trials were identified by the search strategy, and 132 eligible trials were included. Over time the sample size of P3 RCTs in mCRC has been increasing and there has been a steady increase in trials studying targeted therapy (see table below for detailed results by decade). A trend towards a smaller percentage of P3 RCTs sponsored by co-operative groups has been observed in recent decades. The most common primary endpoint was overall survival (OS) which was used in 35% of the trials. A decreasing trend in the use of OS was observed since the 1990s. Other common primary endpoints include: progression-free survival (PFS) in 28% and response rate (RR) in 20% of the P3 RCTs. The primary endpoint was met in 45% of the trials. There was discordance between the primary endpoint significance and the authors’ conclusions in 14% of the trials. Conclusions: The design and interpretation of P3 RCTs for mCRC has changed over time from 1980 to present. The use of OS as the primary endpoint is decreasing, while the use of PFS is increasing. [Table: see text]


Author(s):  
Frauke Jürgens ◽  
Kai Rothaus ◽  
Henrik Faatz ◽  
Britta Heimes-Bussmann ◽  
Daniel Pauleikhoff ◽  
...  

Abstract Background Early and intermediate age-related macular degeneration (AMD) results in drusen deposits under the retinal pigment epithelium (RPE). These early stages of AMD exhibit different risks of progressing to late AMD. To date, early AMD has been classified and quantified by fundus photography. This does not appear to be sensitive enough for clinical trials studying the impact on drusen. SD-OCT with two-dimensional rendering of the segmented slices analysed allows for en face imaging of the drusen. The present trial studied the potential of quantifying early and intermediate AMD by en-face optical coherence tomography (OCT). Material and Methods Thirty-one eyes of 29 patients in different stages of early and intermediate AMD were studied. To this end, fundus photographs (Kowa VX-10i, Kowa, Tokyo, Japan) and en-face OCT images (RTVue XR Avanti, Optovue, Inc., Fremont, CA, USA) were taken. First, different segmentation levels (6 µm underneath the RPE, on the RPE, 6 µm and 9 µm above the RPE) and different layer thicknesses (5 µm, 10 µm, 20 µm and 30 µm) were analysed to determine the best segmentation for visualising drusen. Drusen were marked manually and their number and surface area calculated. This analysis was then compared with the standardised drusen analyses on fundus photography. Additional changes in early and intermediate AMD such as pigment epithelial detachments (PEDs) and subretinal drusenoid deposits (SDD) as well as small atrophies were also documented and compared. Outcomes The best segmentation for delineating the drusen on the en-face OCT images was found to be a segmentation 6 µm underneath the RPE with a slice thickness of 20 µm. Comparison of drusen quantification on en-face OCT images with the standardised drusen analysis on fundus photography revealed particularly good similarity. Other changes in early and intermediate AMD, such as PEDs, SDD and small atrophies, were easier to assess on the en-face OCT images. Conclusions The analysis and quantification of drusen from en-face OCT images with 20 µm segmentation at 6 µm underneath the RPE allows differentiated quantification of various drusen characteristics. Moreover, other changes in early and intermediate AMD can also be analysed. In future observational and clinical trials, this could help quantify drusen.


2018 ◽  
Vol 8 (2) ◽  
pp. 50-59
Author(s):  
M. Yu. Fedyanin ◽  
S. A. Tjulandin

In this review we analyzed results of studies concerning the choice of first and subsequent lines of therapy in patients with metastatic colon cancer. We discussed data of various combinations of monoclonal antibodies with different chemotherapeutic regimens. Also we discussed modern preclinical and clinical trials concerning strategy of choice of targeted therapy sequence in patients with metastatic disease. We considered the impact of various molecular and clinical factors on the effectiveness of drugs and determined their application for therapy choice for colon cancer.


Sign in / Sign up

Export Citation Format

Share Document