Abstract:
BACKGROUND:The logrank test is routinely applied to design and analyse randomized controlled trials (RCTs) with time-to-event outcomes. Sample size and power calculations assume the treatment effect follows proportional hazards (PH). If the PH assumption is false, power is reduced and interpretation of the hazard ratio (HR) as the estimated treatment effect is compromised. Using statistical simulation, we investigated the type 1 error and power of the logrank (LR)test and eight alternatives. We aimed to identify test(s) that improve power with three types of non-proportional hazards (non-PH): early, late or near-PH treatment effects. METHODS:We investigated weighted logrank tests (early, LRE; late, LRL), the supremum logrank test (SupLR) and composite tests (joint, J; combined, C; weighted combined, WC; versatile and modified versatile weighted logrank, VWLR, VWLR2) with two or more components. Weighted logrank tests are intended to be sensitive to particular non-PH patterns. Composite tests attempt to improve power across a wider range of non-PH patterns. Using extensive simulations based on real trials, we studied test size and power under PH and under simple departures from PH comprising pointwise constant HRs with a single change point at various follow-up times. We systematically investigated the influence of high or low control-arm event rates on power. RESULTS:With no preconceived type of treatment effect, the preferred test is VWLR2. Expecting an early effect, tests with acceptable power are SupLR, C, VWLR2, J, LRE and WC. Expecting a late effect, acceptable tests are LRL, VWLR, VWLR2, WC and J. Under near-PH, acceptable tests are LR, LRE, VWLR, C, VWLR2 and SupLR. Type 1 error was well controlled for all tests, showing only minor deviations from the nominal 5%. The location of the HR change point relative to the cumulative proportion of control-arm events considerably affected power. CONCLUSIONS:Assuming ignorance of the likely treatment effect, the best choice is VWLR2. Several non-standard tests performed well when the correct type of treatment effect was assumed. A low control-arm event rate reduced the power of weighted logrank tests targeting early effects. Test size was generally well controlled. Further investigation of test characteristics with different types of non-proportional hazards of the treatment effect is warranted.
journal_name
Trialsjournal_title
Trialsauthors
Royston P,B Parmar MKdoi
10.1186/s13063-020-4153-2subject
Has Abstractpub_date
2020-04-06 00:00:00pages
315issue
1issn
1745-6215pii
10.1186/s13063-020-4153-2journal_volume
21pub_type
杂志文章相关文献
Trials文献大全abstract:BACKGROUND:Staphylococcus aureus bacteremia (SAB) is frequently encountered in the hospital setting, and current guidelines recommend at least 14 days of antibiotic treatment for SAB in order to minimize risks of secondary deep infections and relapse. However, evidence to support these treatment recommendations remains...
journal_title:Trials
pub_type: 杂志文章
doi:10.1186/s13063-019-3357-9
更新日期:2019-05-02 00:00:00
abstract:BACKGROUND:Feeding practices and child undernutrition can be improved when trained health workers provide proper nutrition counseling to caregivers. However, this important management component is difficult to achieve in countries where trained health workers are limited; Tanzania is no exception. In rural and semi-urb...
journal_title:Trials
pub_type: 杂志文章,多中心研究,随机对照试验
doi:10.1186/1745-6215-14-352
更新日期:2013-10-25 00:00:00
abstract:BACKGROUND:Low back pain (LBP) is a common cause of disability among U.S. military personnel. Approximately 20% of all diagnoses resulting in disability discharges are linked to back-related conditions. Because LBP can negatively influence trunk muscle strength, balance, and endurance, the military readiness of active-...
journal_title:Trials
pub_type: 杂志文章
doi:10.1186/s13063-018-3041-5
更新日期:2018-12-05 00:00:00
abstract:BACKGROUND:Enrollment in interventional therapeutic clinical trials is a small fraction of all patients who might participate given reasonable access. METHODS:A hierarchical approach is utilized in measuring staged participation from trial availability to patient enrollment. Our framework suggests that concern for jus...
journal_title:Trials
pub_type: 杂志文章
doi:10.1186/1745-6215-13-237
更新日期:2012-12-10 00:00:00
abstract:BACKGROUND:Home parenteral nutrition (HPN) is a life-preserving therapy for patients with chronic intestinal failure (CIF) indicated for patients who cannot achieve their nutritional requirements by enteral intake. Intravenously administered lipid emulsions (ILEs) are an essential component of HPN, providing energy and...
journal_title:Trials
pub_type: 杂志文章,多中心研究,随机对照试验
doi:10.1186/s13063-019-3994-z
更新日期:2019-12-30 00:00:00
abstract:BACKGROUND:Non-communicable chronic diseases are linked to behavioral risk factors (including smoking, poor diet and physical inactivity), so effective behavior change interventions are needed to improve population health. However, uptake and impact of these interventions is limited by methodological challenges. We aim...
journal_title:Trials
pub_type: 杂志文章
doi:10.1186/s13063-020-04235-z
更新日期:2020-03-23 00:00:00
abstract:BACKGROUND:Depression is common in residents of Residential and Nursing homes (RNHs). It is usually undetected and often undertreated. Depression is associated with poor outcomes including increased morbidity and mortality. Exercise has potential to improve depression, and has been shown in existing trials to improve o...
journal_title:Trials
pub_type: 杂志文章,多中心研究,随机对照试验
doi:10.1186/1745-6215-12-27
更新日期:2011-02-02 00:00:00
abstract:BACKGROUND:Patients with type 2 diabetes (T2DM) are at increased risk for macrovascular events as well as for microvascular complications. There is evidence that in patients with coronary artery disease (CAD), about 35 % suffer from manifest T2DM. Early glucose-lowering intervention in subjects with T2DM has been demon...
journal_title:Trials
pub_type: 杂志文章,随机对照试验
doi:10.1186/s13063-016-1627-3
更新日期:2016-10-13 00:00:00
abstract:BACKGROUND:Classroom-based stuttering intervention addressing negative peer attitudes, perceptions, teasing and bullying of children who stutter (CWS) is required as part of holistic stuttering management because of its occurrence in primary school. This study was conducted in 2017, in 10 primary schools in the Western...
journal_title:Trials
pub_type: 杂志文章,多中心研究,随机对照试验
doi:10.1186/s13063-018-3043-3
更新日期:2018-11-29 00:00:00
abstract:BACKGROUND:Ascites is one of the most common complications of cirrhosis. Umbilical therapy with traditional Chinese medicines has been increasingly prescribed to treat cirrhotic ascites. However, high-quality evidence from clinical trials supporting such application of traditional Chinese medicines remains limited. The...
journal_title:Trials
pub_type: 杂志文章,多中心研究
doi:10.1186/s13063-019-3221-y
更新日期:2019-02-13 00:00:00
abstract:BACKGROUND:After major abdominal surgery (MAS), 20% of patients endure major complications, which require invasive treatment and are associated with increased morbidity and mortality. A quality control algorithm after major abdominal surgery aimed at early identification of patients at risk of developing major complica...
journal_title:Trials
pub_type: 临床试验,杂志文章,多中心研究
doi:10.1186/s13063-015-0903-y
更新日期:2015-08-28 00:00:00
abstract:BACKGROUND:This study aims to evaluate the feasibility and efficacy of a complex health intervention, based on the combination of conventional Western medicine and traditional Chinese medicine (TCM), in an outpatient department of a university hospital for patients with frequent episodic or chronic tension-type headach...
journal_title:Trials
pub_type: 杂志文章
doi:10.1186/s13063-019-3700-1
更新日期:2019-11-08 00:00:00
abstract:BACKGROUND:Recognizing the value of promoting public access to clinical trial protocols, Trials pioneered the way for their publication over a decade ago. However, despite major advances in the public accessibility of information about trial methods and results, protocol sharing remains relatively rare. MAIN BODY:Prot...
journal_title:Trials
pub_type: 信件
doi:10.1186/s13063-018-2510-1
更新日期:2018-02-17 00:00:00
abstract:BACKGROUND:The reported incidence of peripheral intravenous catheter (PIV) failure has been as high as 69%. This is in part due to inadequate stabilisation or securement to the skin, which allows micro-motion of the catheter within the vein. METHODS:A pilot open randomised controlled trial of 300 patients was conducte...
journal_title:Trials
pub_type: 杂志文章,随机对照试验
doi:10.1186/s13063-018-2985-9
更新日期:2018-10-30 00:00:00
abstract::There are many acknowledged benefits for the reuse of clinical trial data; from independent verification of published results to the evaluation of new hypotheses. However, the reuse of shared clinical trial data is not without obstacles. Here we present some of the issues and lessons learned from our own experiences i...
journal_title:Trials
pub_type: 信件
doi:10.1186/s13063-019-3627-6
更新日期:2019-08-19 00:00:00
abstract:BACKGROUND:The German welfare system follows the principle "rehabilitation rather than pension," but more than the half of all disability pensioners did not utilize medical rehabilitation before their early retirement. A major barrier is the application procedure. Lack of information about the opportunity to utilize re...
journal_title:Trials
pub_type: 杂志文章,随机对照试验
doi:10.1186/s13063-015-0968-7
更新日期:2015-09-29 00:00:00
abstract:BACKGROUND:Diabetic foot ulcers (DFUs) represent a significant source of morbidity and an enormous financial burden. Standard care for DFUs involves systemic glucose control, ensuring adequate perfusion, debridement of nonviable tissue, off-loading, control of infection, local wound care and patient education, all admi...
journal_title:Trials
pub_type: 杂志文章,随机对照试验
doi:10.1186/1745-6215-14-8
更新日期:2013-01-09 00:00:00
abstract:BACKGROUND:The key aim of the study is to establish an agreed standardised core outcome set (COS) for use when evaluating non-pharmacological health and social care interventions for people living at home with dementia. METHODS/DESIGN:Drawing on the guidance and approaches of the Core Outcome Measures in Effectiveness...
journal_title:Trials
pub_type: 杂志文章
doi:10.1186/s13063-018-2584-9
更新日期:2018-04-24 00:00:00
abstract:BACKGROUND:Despite the promise and popularity of advance care planning, there is insufficient evidence that advance care planning helps patients to meet their end-of-life care preferences, especially in Asian settings. Thus, the proposed study aims to assess whether patients with advanced heart failure who are receivin...
journal_title:Trials
pub_type: 杂志文章,多中心研究,随机对照试验
doi:10.1186/s13063-016-1414-1
更新日期:2016-06-10 00:00:00
abstract:BACKGROUND:Despite worldwide interest in reducing re-hospitalization, there is limited knowledge regarding characteristics of patients who chose to decline participation in such efforts and why. The aim is to explore reasons to decline participation in an intervention using motivational interviewing to reduce re-hospit...
journal_title:Trials
pub_type: 杂志文章
doi:10.1186/s13063-019-3187-9
更新日期:2019-01-25 00:00:00
abstract:BACKGROUND:Motivational interviewing (MI) has great potential in changing health-related behaviors. In addition to delivery in face-to-face individual counseling, MI can be delivered through online groups, a method that is particularly appealing to adolescents and may offer several benefits. This randomized controlled ...
journal_title:Trials
pub_type: 杂志文章,多中心研究,随机对照试验
doi:10.1186/s13063-015-0946-0
更新日期:2015-09-18 00:00:00
abstract:BACKGROUND:A large number of stakeholders have accepted the need for greater transparency in clinical research and, in the context of various initiatives and systems, have developed a diverse and expanding number of repositories for storing the data and documents created by clinical studies (collectively known as data ...
journal_title:Trials
pub_type: 杂志文章
doi:10.1186/s13063-016-1686-5
更新日期:2016-11-24 00:00:00
abstract:BACKGROUND:Youth depression is highly prevalent and is related to impairments in academic, social and behavioural functioning. Evidence-based treatments are available, but many young people do not respond or sufficiently recover with first-line options, and a significant proportion experience relapse. Consequently, the...
journal_title:Trials
pub_type: 杂志文章,随机对照试验
doi:10.1186/s13063-019-4036-6
更新日期:2020-01-14 00:00:00
abstract::Following the South African case, Treatment Action Campaign and Others v Minister of Health and Others, the use of 'pilot' studies to investigate interventions already proven efficacious, offered free of charge to government, but confined by the government to a small part of the population, may violate children's righ...
journal_title:Trials
pub_type: 杂志文章,评审
doi:10.1186/1745-6215-15-287
更新日期:2014-07-16 00:00:00
abstract:BACKGROUND:Three decades of research suggests that prevention of iron deficiency anemia (IDA) in the primary care setting may be an unrealized and unique opportunity to prevent poor developmental outcomes in children. A longitudinal study of infants with IDA showed that the developmental disadvantage persists long term...
journal_title:Trials
pub_type: 杂志文章,多中心研究,随机对照试验
doi:10.1186/s13063-015-0635-z
更新日期:2015-04-02 00:00:00
abstract:BACKGROUND:Quadriplegia is a severe, catastrophic injury that predominantly affects people early in life, resulting in lifelong physical disability. Obstructive sleep apnoea is a direct consequence of quadriplegia and is associated with neurocognitive deficits, sleepiness and reduced quality of life. The usual treatmen...
journal_title:Trials
pub_type: 杂志文章,多中心研究,随机对照试验
doi:10.1186/1745-6215-14-181
更新日期:2013-06-19 00:00:00
abstract:BACKGROUND:There is no existing report on the quality of randomized controlled trials (RCTs) of melasma treatment currently conducted in China. This study aims to assess the quality of RCT- reporting in the treatment of melasma conducted in China. METHODS:Several databases were searched from their inception through to...
journal_title:Trials
pub_type: 杂志文章
doi:10.1186/s13063-015-0677-2
更新日期:2015-04-12 00:00:00
abstract:BACKGROUND:Single-sided deafness (SSD) describes the presence of a unilateral severe to profound sensorineural hearing loss. SSD disrupts spatial hearing and understanding speech in background noise. It has functional, psychological and social consequences. Potential options for rehabilitation include hearing aids and ...
journal_title:Trials
pub_type: 杂志文章
doi:10.1186/s13063-020-4094-9
更新日期:2020-03-04 00:00:00
abstract:BACKGROUND:Spontaneous recovery from articular cartilage injury is difficult, and the ongoing progression of disease can eventually lead to osteoarthritis. Currently, there is no effective non-surgical treatment for articular cartilage injury. Arthroscopic debridement and microfracture surgery are performed for fibroca...
journal_title:Trials
pub_type: 杂志文章,随机对照试验
doi:10.1186/s13063-017-2251-6
更新日期:2017-11-06 00:00:00
abstract:BACKGROUND:Pharmacological therapies of proven efficacy in coronavirus disease 2019 (COVID-19) are still lacking. We have identified IFNβ-1a as the most promising drug to be repurposed for COVID-19. The rationale relies on the evidence of IFNβ anti-viral activity in vitro against SARS-CoV-2 and animal models resembling...
journal_title:Trials
pub_type: 杂志文章,随机对照试验
doi:10.1186/s13063-020-04864-4
更新日期:2020-11-23 00:00:00