Understanding the predictive value of continuous markers for censored survival data using a likelihood ratio approach.

abstract：BACKGROUND:Cancer relapses may be useful to predict the risk of death. To take into account relapse information, the Landmark approach is popular. As an alternative, we propose the joint frailty model for a recurrent event and a terminal event to derive dynamic predictions of the risk of death. METHODS:The proposed pr...

journal_title：BMC medical research methodology

authors： Mauguen A,Rachet B,Mathoulin-Pélissier S,Lawrence GM,Siesling S,MacGrogan G,Laurent A,Rondeau V

更新日期：2015-04-01 00:00:00

abstract：BACKGROUND:Recruitment to clinical trials can be challenging. Methods that improve the efficiency of trial recruitment are needed to increase successful study completions. The aim of this study was to ascertain whether sending an audio-visual presentation on a digital versatile disc (DVD), along with usual study invita...

journal_title：BMC medical research methodology

authors： Rogers A,Flynn RWV,Mackenzie IS,MacDonald TM

更新日期：2019-01-30 00:00:00

abstract：BACKGROUND:It has been demonstrated that the enclosure of money with a mailed questionnaire increases the response rate significantly. We evaluated scratch lottery tickets as an alternative to cash. METHODS:1500 randomly selected Norwegians between the ages of 40 and 65 years were sent a short questionnaire. 250 recei...

journal_title：BMC medical research methodology

authors： Finsen V,Storeheier AH

更新日期：2006-04-28 00:00:00

abstract：BACKGROUND:When investigating subgroup effects in meta-analysis, it is unclear whether accounting in meta-regression for between-trial variation in treatment effects, but not between-trial variation in treatment interaction effects when such effects are present, leads to biased estimates, coverage problems, or wrong st...

journal_title：BMC medical research methodology

authors： da Costa BR,Sutton AJ

更新日期：2019-10-26 00:00:00

abstract：BACKGROUND:Defeat and entrapment have been shown to be of central relevance to the development of different disorders. However, it remains unclear whether they represent two distinct constructs or one overall latent variable. One reason for the unclarity is that traditional factor analytic techniques have trouble estim...

journal_title：BMC medical research methodology

authors： Forkmann T,Teismann T,Stenzel JS,Glaesmer H,de Beurs D

更新日期：2018-01-25 00:00:00

abstract：:The quality of a consultation provided by a physician can have a profound impact on the quality of care and patient engagement in treatment decisions. When the COPD Assessment Test (CAT) was developed, one of its aims was to aid the communication between physician and patient about the impact of COPD. We developed a n...

journal_title：BMC medical research methodology

authors： Gruffydd-Jones K,Marsden H,Holmes S,Kardos P,Escamilla R,Dal Negro R,Roberts J,Nadeau G,Leather D,Jones P

更新日期：2013-05-10 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:Competing risks are a common occurrence in survival analysis. They arise when a patient is at risk of more than one mutually exclusive event, such as death from different causes, and the occurrence of one of these may prevent any other event from ever happening. METHODS:There are two main approaches to mode...

journal_title：BMC medical research methodology

authors： Hinchliffe SR,Lambert PC

更新日期：2013-02-06 00:00:00

abstract：BACKGROUND:Many biological variables sampled from human subjects show a diurnal pattern, which poses special demands on the techniques used to analyze such data. Furthermore, most biological variables belong to nonlinear dynamical systems, which may make linear statistical techniques less suitable to analyze their dyna...

journal_title：BMC medical research methodology

authors： Toonen RB,Wardenaar KJ,Bos EH,van Ockenburg SL,de Jonge P

更新日期：2018-03-21 00:00:00

abstract：BACKGROUND:The Patient Reported Outcomes Measurement Information System 43-item short form (PROMIS-43) and the five-level EQ-5D (EQ-5D-5L) are recently developed measures of health-related quality of life (HRQL) that have potentially broad application in evaluating treatments and capturing burden of respiratory-related...

journal_title：BMC medical research methodology

authors： Lin FJ,Pickard AS,Krishnan JA,Joo MJ,Au DH,Carson SS,Gillespie S,Henderson AG,Lindenauer PK,McBurnie MA,Mularski RA,Naureckas ET,Vollmer WM,Lee TA,CONCERT Consortium.

更新日期：2014-06-16 00:00:00

abstract：BACKGROUND:The longitudinal birth cohort study is the preferred design for studies of childhood health, particularly atopic disease. Still, prospective data collection depends on recollection of the medical history since the previous visit representing a potential recall-bias. We aimed to ascertain the quality of infor...

journal_title：BMC medical research methodology

authors： Vissing NH,Jensen SM,Bisgaard H

更新日期：2012-10-22 00:00:00

abstract：BACKGROUND:Quantitative Microbial Risk Assessment (QMRA), a modelling approach, is used to assess health risks. Inputs into the QMRA process include data that characterise the intensity, frequency and duration of exposure to risk(s). Data gaps for water exposure assessment include the duration and frequency of urban no...

journal_title：BMC medical research methodology

authors： O'Toole JE,Sinclair MI,Leder K

更新日期：2009-11-09 00:00:00

abstract：BACKGROUND:Diagnostic problems in clinical trials are sometimes ordinal. For example, colon tumor staging was performed according to the TNM classification. However, clinical data are limited by markedly small sample sizes in some stage. METHODS:We propose a distribution-free test for detecting ordered alternatives in...

journal_title：BMC medical research methodology

authors： Chang CH,Chin CC,Yu WW,Huang YY

更新日期：2013-12-05 00:00:00

abstract：BACKGROUND:One of the main challenges for drug evaluation in rare diseases is the often heterogeneous course of these diseases. Traditional outcome measures may not be applicable for all patients, when they are in different stages of their disease. For instance, in Duchenne Muscular Dystrophy, the Six Minute Walk Test ...

journal_title：BMC medical research methodology

authors： Gaasterland CM,Jansen-van der Weide MC,Weinreich SS,van der Lee JH

更新日期：2016-08-17 00:00:00

abstract：BACKGROUND:Centralisation of thrombolysis may offer substantial benefits. The aim of this study was to assess short term costs and effects of centralisation of thrombolysis and optimised care in a decentralised system. METHODS:Using simulation modelling, three scenarios to improve decentralised settings in the North o...

journal_title：BMC medical research methodology

authors： Lahr MM,van der Zee DJ,Luijckx GJ,Vroomen PC,Buskens E

更新日期：2017-01-10 00:00:00

abstract：BACKGROUND:Polypharmacy can be either beneficial or harmful to children. We conducted a scoping review to examine the concept of pediatric polypharmacy: its definition, prevalence, extent and gaps in research. In this manuscript, we report our transdisciplinary scoping review methodology. METHODS:After establishing a ...

journal_title：BMC medical research methodology

authors： Bakaki PM,Staley J,Liu R,Dawson N,Golchin N,Horace A,Johnson H,Waldron J,Winterstein A,Kleinman LC,Bolen SD

更新日期：2018-10-04 00:00:00

abstract：BACKGROUND:Statistical time series derived from administrative data sets form key indicators in measuring progress in addressing disadvantage in Aboriginal and Torres Strait Islander populations in Australia. However, inconsistencies in the reporting of Indigenous status can cause difficulties in producing reliable ind...

journal_title：BMC medical research methodology

authors： Lawrence D,Christensen D,Mitrou F,Draper G,Davis G,McKeown S,McAullay D,Pearson G,Zubrick SR

更新日期：2012-07-02 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: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:Thresholds for statistical significance are insufficiently demonstrated by 95% confidence intervals or P-values when assessing results from randomised clinical trials. First, a P-value only shows the probability of getting a result assuming that the null hypothesis is true and does not reflect the probabilit...

journal_title：BMC medical research methodology

authors： Jakobsen JC,Gluud C,Winkel P,Lange T,Wetterslev J

更新日期：2014-03-04 00:00:00

abstract：BACKGROUND:International clinical trials are now rapidly expanding into Asia. However, the proportion of global trials is higher in South Korea compared to Japan despite implementation of similar governmental support in both countries. The difference in clinical trial environment might influence the respective physicia...

journal_title：BMC medical research methodology

authors： Ito-Ihara T,Hong JH,Kim OJ,Sumi E,Kim SY,Tanaka S,Narita K,Hatta T,Choi EK,Choi KJ,Miyagawa T,Minami M,Murayama T,Yokode M

更新日期：2013-10-25 00:00:00

abstract：BACKGROUND:We would expect information on adverse drug reactions in randomised clinical trials to be easily retrievable from specific searches of electronic databases. However, complete retrieval of such information may not be straightforward, for two reasons. First, not all clinical drug trials provide data on the fre...

journal_title：BMC medical research methodology

authors： Derry S,Loke YK,Aronson JK

更新日期：2001-01-01 00:00:00

abstract：BACKGROUND:Multiple imputation is frequently used to deal with missing data in healthcare research. Although it is known that the outcome should be included in the imputation model when imputing missing covariate values, it is not known whether it should be imputed. Similarly no clear recommendations exist on: the util...

journal_title：BMC medical research methodology

authors： Kontopantelis E,White IR,Sperrin M,Buchan I

更新日期：2017-01-09 00:00:00

abstract：BACKGROUND:Clinical practice guidelines have become increasingly widely used to guide quality improvement of clinical practice. Qualitative research may be a useful way to improve the quality and implementation of guidelines. The methodology for qualitative evidence used in guidelines development is worthy of further r...

journal_title：BMC medical research methodology

authors： Wang YY,Liang DD,Lu C,Shi YX,Zhang J,Cao Y,Fang C,Huang D,Jin YH

更新日期：2020-06-17 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:Estimating the incidence of medical conditions using claims data often requires constructing a prevalence period that predates an event of interest, for instance the diagnosis of cancer, to exclude those with pre-existing conditions from the incidence risk set. Those conditions missed during the prevalence p...

journal_title：BMC medical research methodology

authors： Griffiths RI,O'Malley CD,Herbert RJ,Danese MD

更新日期：2013-03-06 00:00:00

abstract：BACKGROUND:Identifying and assessing degree and type of frailty among older persons is a major challenge when targeting high risk populations to identify preventive interventions. The Vulnerable Elders Survey-(VES-13) is a simple instrument to identify frailty defined as risk for death, functional decline or institutio...

journal_title：BMC medical research methodology

authors： Belmin J,Khellaf L,Pariel S,Jarzebowski W,Valembois L,Zeisel J,Lafuente-Lafuente C

更新日期：2020-02-05 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:Although some nonparametric methods have been proposed in the literature to test for the equality of median survival times for censored data in medical research, in general they have inflated type I error rates, which make their use limited in practice, especially when the sample sizes are small. METHODS:In...

journal_title：BMC medical research methodology

authors： Chen Z,Zhang G

更新日期：2016-03-16 00:00:00

abstract：BACKGROUND:There is analytical potential for multiple cause of death data collected from death certificates. This study examines relationships of multiple causes of death as a function of factors available on the death certificate (demographics of decedent, place of death, type of certifier, disposal method, whether an...

journal_title：BMC medical research methodology

authors： Wall MM,Huang J,Oswald J,McCullen D

更新日期：2005-01-17 00:00:00