Abstract:
:An instrumental variable (IV) estimator has been widely used to estimate causal effects among compliers in randomized trials with noncompliance. The estimator of complier average treatment effect can be expressed as a ratio of two unbiased estimators but the ratio estimator is not unbiased. The bias of IV estimator can be substantial when the sample size is small, or when there is substantial noncompliance. A simple adjustment to the standard instrumental variable estimator is studied to lower the bias. The bias corrected estimator can lower the bias in an order of magnitude, and we verify by numerical examples that the bias corrected estimator can have substantially lower bias and mean squared error compared to the usual IV estimator for small to moderate sample sizes. The proposed point estimator does not need an iterative procedure to implement and can perform well even when the outcome distributions of compliers and non-compliers do not overlap. We also discuss situations where the IV estimator and the proposed estimator can consistently estimate the population average treatment effect.
journal_name
Contemp Clin Trialsjournal_title
Contemporary clinical trialsauthors
Chan KCdoi
10.1016/j.cct.2012.03.013subject
Has Abstractpub_date
2012-07-01 00:00:00pages
786-93issue
4eissn
1551-7144issn
1559-2030pii
S1551-7144(12)00089-4journal_volume
33pub_type
杂志文章abstract:BACKGROUND:Mindfulness-based relapse prevention (MBRP) is a method that combines cognitive behavioral relapse prevention with mindfulness practice. Research suggests that MBRP can effectively reduce withdrawal/craving in people with substance use disorder (SUD). An important part of MBRP is to practice mindfulness medi...
journal_title:Contemporary clinical trials
pub_type: 杂志文章,随机对照试验
doi:10.1016/j.cct.2018.04.006
更新日期:2018-07-01 00:00:00
abstract:BACKGROUND:The Covid-19 pandemic has caused fear and panic worldwide, forcing healthcare systems to disregard conventional practices and adopt innovation to contain the infection and death. Globally, there has been a rapid proliferation of research studies and clinical trials assessing risks, infectivity and treatment....
journal_title:Contemporary clinical trials
pub_type: 杂志文章,评审
doi:10.1016/j.cct.2020.106106
更新日期:2020-09-01 00:00:00
abstract:BACKGROUND:Functional dyspepsia (FD) is a common problem affecting up to 10-25% of individuals. FD accounts for significant health care costs and affects quality of life but has no definitive treatment. OBJECTIVES:The Functional Dyspepsia Treatment Trial (FDTT) aims to test whether treatment with an antidepressant (am...
journal_title:Contemporary clinical trials
pub_type: 杂志文章,随机对照试验
doi:10.1016/j.cct.2012.02.002
更新日期:2012-05-01 00:00:00
abstract::Home-based telemedicine (HBT) is a validated method of evidence-based treatment delivery for posttraumatic stress disorder (PTSD), and justification for its use has centered on closing gaps related to provider availability and distance to treatment centers. However, another potential use of HBT may be to overcome barr...
journal_title:Contemporary clinical trials
pub_type: 杂志文章,随机对照试验
doi:10.1016/j.cct.2016.03.004
更新日期:2016-05-01 00:00:00
abstract:BACKGROUND:Evaluation of new therapies for cancer has suffered a paradigm shift in the last years. The use of innovative and more efficient designs is a priority for the scientific community; nevertheless, the use of this kind of design is not yet wide spread. PURPOSE:In this paper will examine the effectiveness of ad...
journal_title:Contemporary clinical trials
pub_type: 杂志文章,评审
doi:10.1016/j.cct.2011.09.017
更新日期:2012-01-01 00:00:00
abstract::Caregivers for a family member with dementia experience chronic long-term stress that may benefit from new complementary therapies such as mindfulness-based stress reduction. Little is known however, about the challenges of recruiting and retaining family caregivers to research on mind-body based complementary therapi...
journal_title:Contemporary clinical trials
pub_type: 杂志文章
doi:10.1016/j.cct.2011.05.002
更新日期:2011-09-01 00:00:00
abstract:BACKGROUND:Thousands of people die annually from prescription opioid overdoses; however there are few strategies to ensure patients receive medication risk information at the time of prescribing. OBJECTIVES:To compare the effectiveness of the Emergency Department (ED) Electronic Medication Complete Communication (EMC2...
journal_title:Contemporary clinical trials
pub_type: 杂志文章,随机对照试验
doi:10.1016/j.cct.2017.05.003
更新日期:2017-08-01 00:00:00
abstract::The Flexibility, Toning, and Balance (FlexToBa) Trial is a two-armed randomized controlled trial which will contrast the effects of a DVD-delivered, home-based, physical activity intervention and a Healthy Aging attention control condition on physical activity, functional performance, functional limitations, and quali...
journal_title:Contemporary clinical trials
pub_type: 杂志文章,多中心研究,随机对照试验
doi:10.1016/j.cct.2011.10.002
更新日期:2012-01-01 00:00:00
abstract::Chronic insomnia disorder is a prevalent condition and a significant proportion of these individuals also have obstructive sleep apnea (OSA). These two sleep disorders have distinct pathophysiology and are managed with different treatment approaches. High comorbidity rates have been a catalyst for emerging studies exa...
journal_title:Contemporary clinical trials
pub_type: 杂志文章,随机对照试验
doi:10.1016/j.cct.2015.12.017
更新日期:2016-03-01 00:00:00
abstract:BACKGROUND:Anxiety and mood disorders involve a high disease burden and are associated with high economic costs. A stepped-care approach intervention and abbreviated diagnostic method are assumed to increase effectiveness and efficiency of the mental healthcare and are expected to reduce economic costs. METHODS:Presen...
journal_title:Contemporary clinical trials
pub_type: 杂志文章,随机对照试验
doi:10.1016/j.cct.2012.05.002
更新日期:2012-09-01 00:00:00
abstract:BACKGROUND:Cancer survivors suffer from long-term adverse effects that reduce health-related quality of life (QOL) and physical functioning, creating an urgent need to develop effective, durable, and disseminable interventions. Harvest for Health, a home-based vegetable gardening intervention, holds promise for these d...
journal_title:Contemporary clinical trials
pub_type: 杂志文章,随机对照试验
doi:10.1016/j.cct.2016.08.014
更新日期:2016-09-01 00:00:00
abstract:INTRODUCTION:Focal therapy (FT) targets individual areas of cancer within the prostate, providing oncological control with minimal side-effects. Early evidence demonstrates encouraging short-medium-term outcomes. With no randomized controlled trials (RCT) comparing FT to radical therapies, Comparative Healthcare Resear...
journal_title:Contemporary clinical trials
pub_type: 杂志文章
doi:10.1016/j.cct.2020.105999
更新日期:2020-06-01 00:00:00
abstract:OBJECTIVE:Characteristics that may influence participation in DNA banks are not well defined. The purpose of this study was to examine characteristics associated with participation in a DNA bank among veterans diagnosed with Amyotrophic Lateral Sclerosis (ALS). METHODS:Veterans who screened eligible for the National R...
journal_title:Contemporary clinical trials
pub_type: 杂志文章
doi:10.1016/j.cct.2007.01.009
更新日期:2007-09-01 00:00:00
abstract::Evaluation of time to event outcomes usually is examined by the Kaplan-Meier method and Cox proportional hazards models. We developed a modified statistical model based on histologic grade and other variables to describe the time-dependent outcome for autologous stem cell transplant (autotransplant) performed for non-...
journal_title:Contemporary clinical trials
pub_type: 杂志文章
doi:10.1016/j.cct.2007.07.005
更新日期:2008-03-01 00:00:00
abstract::Physical therapy (PT) is a key component of treatment for knee osteoarthritis (OA) and can decrease pain and improve function. Given the expected rise in prevalence of knee OA and the associated demand for treatment, there is a need for models of care that cost-effectively extend PT services for patients with this con...
journal_title:Contemporary clinical trials
pub_type: 杂志文章,随机对照试验
doi:10.1016/j.cct.2012.12.007
更新日期:2013-03-01 00:00:00
abstract:BACKGROUND:Atrial fibrillation (AF) increases the risk of thromboembolic stroke. An oral anticoagulant should be administrated to prevent stroke in patients with moderate stroke risk (ie, CHA2DS2-VASc score>2). If the stroke risk is low (i.e. the score=1), however, antiplatelet agent such as aspirin is widely used. Asp...
journal_title:Contemporary clinical trials
pub_type: 杂志文章,多中心研究,随机对照试验
doi:10.1016/j.cct.2017.06.011
更新日期:2017-09-01 00:00:00
abstract::Although colorectal cancer (CRC) is largely preventable through identification of pre-cancerous polyps through various screening modalities, morbidity and mortality rates remain a challenge, especially in African-American, Latino, low-income and uninsured/underinsured patients. Barriers to screening include cost, acce...
journal_title:Contemporary clinical trials
pub_type: 杂志文章
doi:10.1016/j.cct.2016.11.009
更新日期:2017-01-01 00:00:00
abstract:UNLABELLED:Fatigue is a common and distressing symptom that can last for months or years in up to one-third of cancer survivors. Despite its prevalence, the nature and mechanisms of cancer-related fatigue are poorly understood and the available treatments may not provide sufficient relief. Fatigue has been identified a...
journal_title:Contemporary clinical trials
pub_type: 杂志文章,随机对照试验
doi:10.1016/j.cct.2016.07.004
更新日期:2016-07-01 00:00:00
abstract::Low/no-income, African American men are disproportionally burdened by chronic disease resulting from a complex interplay of systemic, sociocultural, and individual factors. These disparities are related to poverty, racism, gender role strain, high levels of stress, low levels of physical activity, and malnutritious di...
journal_title:Contemporary clinical trials
pub_type: 杂志文章
doi:10.1016/j.cct.2020.106240
更新日期:2020-12-07 00:00:00
abstract::Lumbar spinal stenosis is a common degenerative disorder of the spine in elderly patients that can be effectively treated with decompression surgery in some patients. Radiological findings in the diagnostic work-up of the patients do not always correlate well with clinical symptoms, and guidance about when to proceed ...
journal_title:Contemporary clinical trials
pub_type: 杂志文章
doi:10.1016/j.cct.2011.01.015
更新日期:2011-05-01 00:00:00
abstract:BACKGROUND:Many studies on the health effects of the glycemic index (GI) are confounded by differences in the intakes of other macronutrients and fibre. Little data exist about the within- and between-subject variability of the GI. OBJECTIVE:Our objectives were therefore (i) to calculate the GI of eight commonly used ...
journal_title:Contemporary clinical trials
pub_type: 杂志文章,随机对照试验
doi:10.1016/j.cct.2009.08.001
更新日期:2010-01-01 00:00:00
abstract::The combined use of cigarettes and alcohol is associated with an increased risk of morbidity and mortality. Yet, efficacious interventions that address both behaviors concurrently are lacking. Smoking cessation and alcohol modification not only garner health benefits, but there is also value in addressing alcohol use ...
journal_title:Contemporary clinical trials
pub_type: 杂志文章
doi:10.1016/j.cct.2020.106218
更新日期:2020-11-14 00:00:00
abstract::Benign prostatic hyperplasia (BPH) is a highly prevalent condition in aging men, which can be progressive and lead to acute urinary retention (AUR) and the need for surgery. It is commonly treated with alpha-blockers and 5alpha-reductase inhibitors (5ARIs), both of which improve the symptoms of BPH. Long-term treatmen...
journal_title:Contemporary clinical trials
pub_type: 杂志文章,多中心研究,随机对照试验
doi:10.1016/j.cct.2007.07.008
更新日期:2007-11-01 00:00:00
abstract:PURPOSE:Black breast cancer survivors have high rates of obesity and low physical activity levels. Little is known about the acceptability and feasibility of interventions in this population. OBJECTIVE:A two-arm RCT was launched to assess the efficacy of a culturally targeted 12-week multimodal lifestyle intervention ...
journal_title:Contemporary clinical trials
pub_type: 杂志文章,随机对照试验
doi:10.1016/j.cct.2015.12.005
更新日期:2016-01-01 00:00:00
abstract::Phase IIA clinical trials are commonly conducted as pilot studies to evaluate efficacy and safety in selected populations of patients with the disease or condition to be treated or prevented. The efficacy objective is to find preliminarily evidence of the effectiveness or ineffectiveness of study treatments. Go/no-go ...
journal_title:Contemporary clinical trials
pub_type: 杂志文章
doi:10.1016/j.cct.2012.07.006
更新日期:2012-11-01 00:00:00
abstract:OBJECTIVES:To review current publications to examine safety of tai chi (TC). DESIGN:Cochrane Library, EBSCO host and MEDLINE/PubMed were searched for randomized controlled trials (RCTs) including TC as the core intervention and reporting adverse events (AEs). Data were extracted considering active vs. inactive control...
journal_title:Contemporary clinical trials
pub_type: 杂志文章,meta分析
doi:10.1016/j.cct.2019.06.004
更新日期:2019-07-01 00:00:00
abstract:OBJECTIVE:To describe the methodology of a 2-arm randomized controlled trial that compared the effects of a narrative and didactic version of the Witness CARES (Community Awareness, Reach, & Empowerment for Screening) intervention on colorectal cancer screening behavior among African Americans, as well as the cognitive...
journal_title:Contemporary clinical trials
pub_type: 杂志文章,多中心研究,随机对照试验
doi:10.1016/j.cct.2017.11.019
更新日期:2018-02-01 00:00:00
abstract:BACKGROUND:Intake of sugar-sweetened beverages is associated with overweight in observational studies. A possible explanation is that liquid sugars do not satiate and that their intake is not compensated by reduced caloric intake from other foods. However, evidence from intervention studies for this hypothesis is incon...
journal_title:Contemporary clinical trials
pub_type: 杂志文章,多中心研究,随机对照试验
doi:10.1016/j.cct.2011.10.007
更新日期:2012-01-01 00:00:00
abstract:BACKGROUND:Research demonstrates a link between migraine and obesity. Obesity increases the risk of frequent migraines and is associated with migraine prevalence among reproductive-aged women. These findings are substantiated by several plausible mechanisms and emerging evidence of migraine improvements after surgical ...
journal_title:Contemporary clinical trials
pub_type: 杂志文章,随机对照试验
doi:10.1016/j.cct.2013.03.004
更新日期:2013-05-01 00:00:00
abstract:BACKGROUND:With increased internet accessibility worldwide, it is now possible to assemble individuals with rare diseases through web-based patient registries. However, the validity of participant-reported medical diagnoses is unknown. The objective of this study was to evaluate the accuracy of participant-reported Neu...
journal_title:Contemporary clinical trials
pub_type: 杂志文章
doi:10.1016/j.cct.2014.12.006
更新日期:2015-01-01 00:00:00