Managing the resource demands of a large sample size in clinical trials: can you succeed with fewer subjects?

2002 ◽  
Vol 177 (8) ◽  
pp. 437-447 ◽  
Author(s):  
Anthony C Keech ◽  
Val Gebski
2014 ◽  
Vol 19 (1) ◽  
pp. 26 ◽  
Author(s):  
Jian-Jun Chen ◽  
Xi-Mo Wang ◽  
Xing-Qiang Liu ◽  
Wen Li ◽  
Mo Dong ◽  
...  

PEDIATRICS ◽  
1994 ◽  
Vol 94 (6) ◽  
pp. 823-823

"Most [clinical] trials would be of much greater scientific value if they collected ten times less data, both at entry and during follow-up, and were therefore much larger. Peto R, Collins R, Gray R. Large-scale randomized evidence: large, simple trials and overviews of trials. In: Warren KS, Mosteller F, eds. Doing More Good Than Harm: The Evaluation of Health Care Interventions."


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ben-nian Huo ◽  
Mao-lin Ai ◽  
Yun-tao Jia ◽  
Yao Liu ◽  
Yang Wang ◽  
...  

Abstract Background Although discontinuation is common in clinical trials, no study has been conducted to analyse the current situation and reasons for the suspension or discontinuation of drug clinical trials in China. This study aims to analyse the general characteristics and reasons for the discontinuation of registered clinical trials in mainland China and to identify the associated factors. Methods We conducted a cross-sectional observational study of discontinued trials registered in the Drug Trial Registration and Information Publication Platform before March 31, 2020. All trials with a status of terminated or stopped recorded in the platform were classified as discontinued trials and included in the analysis. The basic characteristics of the discontinued trials were recorded, reasons for trial discontinuation were recorded and divided into 4 categories as drug development strategy, trial planning, trial conduct and studied drug. Pearson’s chi-square test and fisher’s exact test were used to compare the differences in reasons for discontinuation between neoplasm trials and non-neoplasm trials, and to examine the associations of trial characteristics with different reasons related to trials discontinuation. Results Three hundred twelve discontinued trials were included in this study. The studied drugs were mainly chemical drugs [229 (73.4%)], and indications of the studied drugs were mainly neoplasms [77 (24.7%)]. Geographical location of the discontinued trials were mostly in northern [114 (36.5%)] and eastern [96 (30.8%)] China. Study type of the included trials was mainly bioequivalence studies [97 (31.1%)]. The most common reason for trial discontinuation was commercial or strategic decision [84 (26.9%)], followed by futility/lack of efficacy [70 (22.4%)]. The number of trial centers, sample size and whether participants had been enrolled were significantly associated with trial discontinuation (P <  0.05). Multiple center trials showed a higher rate of trial discontinuation due to trial conduct related reasons than single center trials (P <  0.05), trials with sample size > 500 showed a higher rate of trial discontinuation due to studied drug related reasons (P < 0.05), and trials enrolled participants showed a lower rate of trial discontinuation due to commercial or strategic decision and a higher rate of trial discontinuation due to studied drug related reasons than trials without enrolled participants (P < 0.05). Besides, neoplasm trials showed a higher rate of trial discontinuation due to poor recruitment and safety comparing with non-neoplasm trials (P < 0.05). Conclusions Trial discontinuation in China mainly occurred because of commercial or strategic decision and futility/lack of efficacy of the studied drug. Clinical trials with multiple centers and a large sample size may more likely be discontinued due to trial conduct related reasons such as good clinical practice. Discontinuation due to drug safety and lack of efficacy in multiple center trials with a large sample size deserves more attention to avoid resources wastes. Full communication with regulatory authorities such as Center for Drug Evaluation and research institutes to develop a feasible protocol is important for sponsors to avoid trial discontinuation due to protocol issues.


2018 ◽  
pp. 437-445
Author(s):  
Gregory S. Thomas

The chapter Heart Rate Response to Exercise reviews the studies performed to estimate a patient’s maximum predicted heart rate. While the commonly used formula (220 – age), developed in 1971, is easy to remember, it underestimates the actual maximum heart rate in older persons. Studies of large sample size have found the maximum heart rate to be relatively independent of sex and physical fitness but to incrementally decline with age. The decrease with age is less than 1 beat per minute per year, however. A more accurate and recommended formula is [(208) – (0.7)(age)] as developed by Tanaka and colleagues.


1970 ◽  
Vol 7 (01) ◽  
pp. 1-20 ◽  
Author(s):  
Ora Engleberg Percus ◽  
Jerome K. Percus

A generating function technique is used to determine the probability that the deviation between two empirical distributions drawn from the same population lies within a given band a specified number of times. We also treat the asymptotic problem of very large sample size, and obtain explicit expressions when the relative number of failures is very small or very large.


2019 ◽  
Vol 24 (4) ◽  
pp. 408-419
Author(s):  
Hongu Meng ◽  
Antony Warden ◽  
Lulu Zhang ◽  
Ting Zhang ◽  
Yiyang Li ◽  
...  

Mass cytometry (CyTOF) is a critical cell profiling tool in acquiring multiparameter proteome data at the single-cell level. A major challenge in CyTOF analysis is sample-to-sample variance arising from the pipetting process, staining variation, and instrument sensitivity. To reduce such variations, cell barcoding strategies that enable the combination of individual samples prior to antibody staining and data acquisition on CyTOF are often utilized. The most prevalent barcoding strategy is based on a binary scheme that cross-examines the existence or nonexistence of certain mass signals; however, it is limited by low barcoding efficiency and high cost, especially for large sample size. Herein, we present a novel barcoding method for CyTOF application based on mass ratiometry. Different mass tags with specific fixed ratios are used to label CD45 antibody to achieve sample barcoding. The presented method exponentially increases the number of possible barcoded samples with the same amount of mass tags compared with conventional methods. It also reduces the overall time for the labeling process to 40 min and avoids the need for expensive commercial barcoding buffer reagents. Moreover, unlike the conventional barcoding process, this strategy does not pre-permeabilize cells before the barcoding procedure, which offers additional benefits in preserving surface biomarker signals.


2019 ◽  
Vol 7 (9) ◽  
pp. 1801053
Author(s):  
Liu Xie ◽  
Rui Tong ◽  
Wen Zhang ◽  
Dejian Wang ◽  
Tao Liu ◽  
...  

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