Validation of death prediction after breast cancer relapses using joint models.

abstract：BACKGROUND:Studies examining incident heart failure (HF) have been limited to select populations. To examine incident HF with broader generalizability, there is need to assemble a HF-free cohort using a geographically-diverse sample. We aimed to develop and validate a simple medication-based strategy for assembling a H...

journal_title：BMC medical research methodology

authors： Goyal P,Mefford MT,Chen L,Sterling MR,Durant RW,Safford MM,Levitan EB

更新日期：2020-03-04 00:00:00

abstract：BACKGROUND:Cluster randomised trials with unequal sized clusters often have lower precision than with clusters of equal size. To allow for this, sample sizes are inflated by a modified version of the design effect for clustering. These inflation factors are valid under the assumption that randomisation is stratified by...

journal_title：BMC medical research methodology

authors： Martin JT,Hemming K,Girling A

更新日期：2019-06-14 00:00:00

abstract：BACKGROUND:One of the biggest challenges for population health studies is the recruitment of participants. Questions that investigators have asked are "who volunteers for studies?" and "does recruitment method influence characteristics of the samples?" The purpose of this paper was to compare sample characteristics of ...

journal_title：BMC medical research methodology

authors： Leung BM,McDonald SW,Kaplan BJ,Giesbrecht GF,Tough SC

更新日期：2013-12-06 00:00:00

abstract：BACKGROUND:Health researchers undertake studies which combine qualitative and quantitative methods. Little attention has been paid to the structural issues affecting this mixed methods approach. We explored the facilitators and barriers to undertaking mixed methods studies in health research. METHODS:Face-to-face semi...

journal_title：BMC medical research methodology

authors： O'Cathain A,Nicholl J,Murphy E

更新日期：2009-12-09 00:00:00

abstract：BACKGROUND:In recent months, multiple efforts have sought to characterize COVID-19 social distancing policy responses. These efforts have used various coding frameworks, but many have relied on coding methodologies that may not adequately describe the gradient in social distancing policies as states "re-open." METHODS...

journal_title：BMC medical research methodology

authors： Lane J,Garrison MM,Kelley J,Sarma P,Katz A

更新日期：2020-12-08 00:00:00

abstract：BACKGROUND:Amyotrophic Lateral Sclerosis (ALS), also known as Lou Gehrig's disease, is a rare disease with extreme between-subject variability, especially with respect to rate of disease progression. This makes modelling a subject's disease progression, which is measured by the ALS Functional Rating Scale (ALSFRS), ver...

journal_title：BMC medical research methodology

authors： Karanevich AG,Statland JM,Gajewski BJ,He J

更新日期：2018-02-06 00:00:00

abstract：BACKGROUND:In spite of efforts to employ risk-based strategies to increase monitoring efficiency in the academic setting, empirical evidence on their effectiveness remains sparse. This mixed-methods study aimed to evaluate the risk-based on-site monitoring approach currently followed at our academic institution. METHO...

journal_title：BMC medical research methodology

authors： von Niederhäusern B,Orleth A,Schädelin S,Rawi N,Velkopolszky M,Becherer C,Benkert P,Satalkar P,Briel M,Pauli-Magnus C

更新日期：2017-02-14 00:00:00

abstract：BACKGROUND:The prevailing view in therapeutic clinical research today is that observational studies are useful for generating new hypotheses and that controlled experiments (i.e., randomized clinical trials, RCTs) are the most appropriate method for assessing and confirming the efficacy of interventions. DISCUSSION:Th...

journal_title：BMC medical research methodology

authors： Sacristán JA

更新日期：2011-04-25 00:00:00

abstract：BACKGROUND:Systematic reviews (SRs) must be of high quality. The purpose of our research was to compare the methodological and reporting quality of original versus updated Cochrane SRs to determine whether updating had improved these two quality dimensions. METHODS:We identified updated Cochrane SRs published in issue...

journal_title：BMC medical research methodology

authors： Shea B,Boers M,Grimshaw JM,Hamel C,Bouter LM

更新日期：2006-06-13 00:00:00

abstract：BACKGROUND:The effectiveness of multiple innovative recruitment strategies for enrolling Black/African American participants to the Adventist Health Study-2 (AHS-2) is described. The study's focus is diet and breast, prostate and colon cancer. METHODS:Promotions centered on trust, relationship building and incentives ...

journal_title：BMC medical research methodology

authors： Herring P,Butler T,Hall S,Bennett H,Montgomery SB,Fraser G

更新日期：2014-04-03 00:00:00

abstract：BACKGROUND:The purpose of this study was to determine the standard tasks performed by clinical research coordinators (CRCs) in oncology clinical trials. METHODS:Forty-one CRCs were anonymously surveyed, using a four-page self-administered questionnaire focused on demographics, qualifications, and professional experien...

journal_title：BMC medical research methodology

authors： Rico-Villademoros F,Hernando T,Sanz JL,López-Alonso A,Salamanca O,Camps C,Rosell R

更新日期：2004-03-25 00:00:00

abstract：BACKGROUND:Missing data present a challenge to many research projects. The problem is often pronounced in studies utilizing self-report scales, and literature addressing different strategies for dealing with missing data in such circumstances is scarce. The objective of this study was to compare six different imputatio...

journal_title：BMC medical research methodology

authors： Shrive FM,Stuart H,Quan H,Ghali WA

更新日期：2006-12-13 00:00:00

abstract：BACKGROUND:Estimating costs is essential to the economic analysis of health care programs. Health care costs are often captured from administrative databases or by patient report. Administrative records only provide a partial representation of health care costs and have additional limitations. Patient-completed questio...

journal_title：BMC medical research methodology

authors： Pinto D,Robertson MC,Hansen P,Abbott JH

更新日期：2011-04-13 00:00:00

abstract：BACKGROUND:The Anglia Menorrhagia Education Study (AMES) is a randomized controlled trial testing the effectiveness of an education package applied to general practices. Binary data are available from two sources; general practitioner reported referrals to hospital, and referrals to hospital determined by independent a...

journal_title：BMC medical research methodology

authors： Nixon RM,Duffy SW,Fender GR

更新日期：2003-09-24 00:00:00

abstract：BACKGROUND:Clinical study reports (CSRs) have been increasingly utilised within academic research in recent years. European Medicines Agency (EMA) Policy 0070 'Phase 1,' which came into effect in January 2015, requires the publication of regulatory documents such as CSRs from central applications in an anonymised forma...

journal_title：BMC medical research methodology

authors： Ferran JM,Nevitt SJ

更新日期：2019-11-05 00:00:00

abstract：BACKGROUND:Nowadays, more and more clinical scales consisting in responses given by the patients to some items (Patient Reported Outcomes - PRO), are validated with models based on Item Response Theory, and more specifically, with a Rasch model. In the validation sample, presence of missing data is frequent. The aim of...

journal_title：BMC medical research methodology

authors： Hardouin JB,Conroy R,Sébille V

更新日期：2011-07-14 00:00:00

abstract：BACKGROUND:Family members are increasingly involved in the care of cancer patients, however many are not prepared for this challenging role. Intervention-based studies are valuable to inform the most appropriate and effective support for caregivers. Barriers in the recruitment of patient/caregiver dyads exist but the r...

journal_title：BMC medical research methodology

authors： Heckel L,Gunn KM,Livingston PM

更新日期：2018-11-21 00:00:00

abstract：BACKGROUND:Controlled clinical trials of health care interventions are either explanatory or pragmatic. Explanatory trials test whether an intervention is efficacious; that is, whether it can have a beneficial effect in an ideal situation. Pragmatic trials measure effectiveness; they measure the degree of beneficial ef...

journal_title：BMC medical research methodology

authors： Godwin M,Ruhland L,Casson I,MacDonald S,Delva D,Birtwhistle R,Lam M,Seguin R

更新日期：2003-12-22 00:00:00

abstract：BACKGROUND:Predicting survival of recipients after liver transplantation is regarded as one of the most important challenges in contemporary medicine. Hence, improving on current prediction models is of great interest.Nowadays, there is a strong discussion in the medical field about machine learning (ML) and whether it...

journal_title：BMC medical research methodology

authors： Kantidakis G,Putter H,Lancia C,Boer J,Braat AE,Fiocco M

更新日期：2020-11-16 00:00:00

abstract：BACKGROUND:Both scientists and the public routinely refer to randomized controlled trials (RCTs) as being the 'gold standard' of scientific evidence. Although there is no question that placebo-controlled RCTs play a significant role in the evaluation of new pharmaceutical treatments, especially when it is important to ...

journal_title：BMC medical research methodology

authors： Kaplan BJ,Giesbrecht G,Shannon S,McLeod K

更新日期：2011-05-11 00:00:00

abstract：BACKGROUND:In clinical trials, study designs may focus on assessment of superiority, equivalence, or non-inferiority, of a new medicine or treatment as compared to a control. Typically, evidence in each of these paradigms is quantified with a variant of the null hypothesis significance test. A null hypothesis is assume...

journal_title：BMC medical research methodology

authors： van Ravenzwaaij D,Monden R,Tendeiro JN,Ioannidis JPA

更新日期：2019-03-29 00:00:00

abstract：BACKGROUND:Generic quality of life (QoL) instruments provide important measures of self-reported wellbeing that can be compared across healthy and clinical populations. The aim of this analysis is to validate the ten-item QoL instrument "QOL10", as well as to confirm the validity of the embedded "QOL5" questionnaire an...

journal_title：BMC medical research methodology

authors： Muller AE,Skurtveit S,Clausen T

更新日期：2016-05-23 00:00:00

abstract：BACKGROUND:Measuring body mass index (BMI) has been proposed as a method of screening for preventive primary care and population surveillance of childhood obesity. However, the accuracy of routinely collected measurements has been questioned. The purpose of this study was to assess the reliability of height, length and...

journal_title：BMC medical research methodology

authors： Carsley S,Parkin PC,Tu K,Pullenayegum E,Persaud N,Maguire JL,Birken CS,TARGet Kids! Collaboration.

更新日期：2019-04-24 00:00:00

abstract：BACKGROUND:Quantitative survey of research articles, as an application of bibliometrics, is an effective tool for grasping overall trends in various medical research fields. This type of survey has been also applied to infectious disease research; however, previous studies were insufficient as they underestimated artic...

journal_title：BMC medical research methodology

authors： Takahashi-Omoe H,Omoe K,Okabe N

更新日期：2009-10-06 00:00:00

abstract：BACKGROUND:Meta-analysis typically involves combining the estimates from independent studies in order to estimate a parameter of interest across a population of studies. However, outliers often occur even under the random effects model. The presence of such outliers could substantially alter the conclusions in a meta-a...

journal_title：BMC medical research methodology

authors： Gumedze FN,Jackson D

更新日期：2011-02-16 00:00:00

abstract：BACKGROUND:The use of health-related quality of life (HRQoL) as an endpoint in cancer clinical trials is growing rapidly. Hence, research into the statistical approaches used to analyze HRQoL data is of major importance, and could lead to a better understanding of the impact of treatments on the everyday life and care ...

journal_title：BMC medical research methodology

authors： Barbieri A,Peyhardi J,Conroy T,Gourgou S,Lavergne C,Mollevi C

更新日期：2017-09-26 00:00:00

abstract：BACKGROUND:Precise predictions of incidence and mortality rates due to breast cancer (BC) are required for planning of public health programs as well as for clinical services. A number of approaches has been established for prediction of mortality using stochastic models. The performance of these models intensely depen...

journal_title：BMC medical research methodology

authors： Mubarik S,Hu Y,Yu C

更新日期：2020-12-09 00:00:00

abstract：BACKGROUND:In order to accurately measure and monitor levels of moderate-to-vigorous physical activity (MVPA) and sedentary behaviour (SB) in older adults, cost efficient and valid instruments are required. To date, the International Physical Activity Questionnaire (IPAQ) has not been validated with older adults (aged ...

journal_title：BMC medical research methodology

authors： Cleland C,Ferguson S,Ellis G,Hunter RF

更新日期：2018-12-22 00:00:00

abstract：BACKGROUND:Variation in counts between subjects at a given speed or work rate are the most important source of error in physical activity (PA) measurements with accelerometers. The aim of this study was to explore how the use of individual accelerometer cut points (ICPs) affected the analysis of PA field data. METHODS...

journal_title：BMC medical research methodology

authors： Aadland E,Steene-Johannessen J

更新日期：2012-11-15 00:00:00

abstract：BACKGROUND:Primary-care based randomized controlled trials (RCTs) build an important evidence base for general practice but little evidence exists about barriers to recruitment which often hamper such trials. We investigated the issues that impeded and facilitated recruitment to a clinical trial in general practice. M...

journal_title：BMC medical research methodology

authors： Foster JM,Sawyer SM,Smith L,Reddel HK,Usherwood T

更新日期：2015-03-12 00:00:00