Joint modelling of time-to-event and multivariate longitudinal outcomes: recent developments and issues.

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:Missing data are common in medical research, which can lead to a loss in statistical power and potentially biased results if not handled appropriately. Multiple imputation (MI) is a statistical method, widely adopted in practice, for dealing with missing data. Many academic journals now emphasise the importa...

journal_title：BMC medical research methodology

authors： Hayati Rezvan P,Lee KJ,Simpson JA

更新日期：2015-04-07 00:00:00

abstract：BACKGROUND:Persistent Pseudomonas aeruginosa (PPA) infection promotes lung function deterioration in children with cystic fibrosis (CF). Although early CF diagnosis through newborn screening (NBS) has been shown to provide nutritional/growth benefit, it is unclear whether NBS lowers the risk of PPA infection and how th...

journal_title：BMC medical research methodology

authors： Wang W,Chen MH,Chiou SH,Lai HC,Wang X,Yan J,Zhang Z

更新日期：2016-09-17 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:Small group research in healthcare is important because it deals with interaction and decision-making processes that can help to identify and improve safer patient treatment and care. However, the number of studies is limited due to time- and resource-intensive data processing. The aim of this study was to e...

journal_title：BMC medical research methodology

authors： Aufegger L,Bicknell C,Soane E,Ashrafian H,Darzi A

更新日期：2019-06-13 00:00:00

abstract：BACKGROUND:The occurrence of communicable diseases (CD) depends on exposure to contagious persons. The effects of exposure to CD are delayed in time and contagious persons remain contagious for several days during which their contagiousness varies. Moreover when multiple exposures occur, it is difficult to know which e...

journal_title：BMC medical research methodology

authors： Payet C,Voirin N,Vanhems P,Ecochard R

更新日期：2013-02-20 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:The reporting of randomised controlled trial (RCT) abstracts is of vital importance. The primary objective of this study was to investigate the association between structure format and RCT abstracts' quality of methodology reporting, informed by the current requirement and usage of structure formats by leadi...

journal_title：BMC medical research methodology

authors： Hua F,Walsh T,Glenny AM,Worthington H

更新日期：2018-01-10 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:Bias in adolescent self-reported height and weight is well documented. Given the importance and widespread use of the National Longitudinal Study of Adolescent to Adult Health (Add Health) data for obesity research, we developed and tested the feasibility and validity of an empirically derived statistical co...

journal_title：BMC medical research methodology

authors： Liechty JM,Bi X,Qu A

更新日期：2016-09-22 00:00:00

abstract：BACKGROUND:Self-administered questionnaires are becoming increasingly common in general practice. Much research has explored methods to increase response rates but comparatively few studies have explored the effect of questionnaire administration on reported answers. METHODS:The aim of this study was to determine the ...

journal_title：BMC medical research methodology

authors： Desborough JA,Butters P,Bhattacharya D,Holland RC,Wright DJ

更新日期：2008-06-27 00:00:00

abstract：BACKGROUND:In randomised controlled trials, the assumption of independence of individual observations is fundamental to the design, analysis and interpretation of studies. However, in individually randomised trials in primary care, this assumption may be violated because patients are naturally clustered within primary ...

journal_title：BMC medical research methodology

authors： Stuart B,Becque T,Moore M,Little P

更新日期：2020-04-15 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:There is increasing awareness that meta-analyses require a sufficiently large information size to detect or reject an anticipated intervention effect. The required information size in a meta-analysis may be calculated from an anticipated a priori intervention effect or from an intervention effect suggested b...

journal_title：BMC medical research methodology

authors： Wetterslev J,Thorlund K,Brok J,Gluud C

更新日期：2009-12-30 00:00:00

abstract：BACKGROUND:Longitudinal studies using data collected as part of usual care risk providing biased results if visit times are related to the outcome of interest. Statistical methods for mitigating this bias are available but rarely used. This lack of use could be attributed to a lack of need or to a lack of awareness of ...

journal_title：BMC medical research methodology

authors： Farzanfar D,Abumuamar A,Kim J,Sirotich E,Wang Y,Pullenayegum E

更新日期：2017-09-06 00:00:00

abstract：BACKGROUND:The term 'inequities' refers to avoidable differences rooted in injustice. This review examined whether or not, and how, quantitative studies identifying inequalities in risk factors and health service utilization for asthma explicitly addressed underlying inequities. Asthma was chosen because recent decades...

journal_title：BMC medical research methodology

authors： Greenwood HL,Edwards N,Hoogbruin A,Kahwa EK,Odhiambo ON,Buong JA

更新日期：2011-07-12 00:00:00

abstract：BACKGROUND:The rationale for commissioning community pulmonary rehabilitation programmes is based on evidence from randomised clinical trials. However, there are a number of reasons why similar programmes might be less effective outside the environment of a clinical trial. These include a less highly selected patient g...

journal_title：BMC medical research methodology

authors： Goyder EC,Strong M,Green A,Holmes MW,Miles G,Reddington O,Lawson R,Lee A,Basran G

更新日期：2013-08-13 00:00:00

abstract：BACKGROUND:The Pathobiology of Prediabetes in A Biracial Cohort study is a prospective evaluation of the transition from normal to impaired glucose regulation among African American and Caucasian adults with parental type 2 diabetes. This report describes recruitment strategies and relative yields for the 376 enrolled ...

journal_title：BMC medical research methodology

authors： Ebenibo S,Edeoga C,Ammons A,Egbuonu N,Dagogo-Jack S,Pathobiology of Prediabetes in a Biracial Cohort (POP-ABC) Research Group.

更新日期：2013-05-10 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:How overall physical activity relates to specific activities and how reported activity changes over time may influence interpretation of observed associations between physical activity and health. We examine the relationships between various physical activities self-reported at different times in a large coh...

journal_title：BMC medical research methodology

authors： Armstrong ME,Cairns BJ,Green J,Reeves GK,Beral V,Million Women Study Collaborators.

更新日期：2011-06-22 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:Within cancer care, dynamic evaluations of the loss in expectation of life provides useful information to patients as well as physicians. The loss of lifetime function yields the conditional loss in expectation of life given survival up to a specific time point. Due to the inevitable censoring in time-to-eve...

journal_title：BMC medical research methodology

authors： Jakobsen LH,Andersson TM,Biccler JL,El-Galaly TC,Bøgsted M

更新日期：2019-01-28 00:00:00

abstract：BACKGROUND:This paper focuses on measuring the efficiency and effectiveness of two diagramming methods employed in key informant interviews with clinicians and health care administrators. The two methods are 'participatory diagramming', where the respondent creates a diagram that assists in their communication of answe...

journal_title：BMC medical research methodology

authors： Umoquit MJ,Dobrow MJ,Lemieux-Charles L,Ritvo PG,Urbach DR,Wodchis WP

更新日期：2008-08-08 00:00:00

abstract：BACKGROUND:To describe how frequently harm is reported in the abstract of high impact factor medical journals. METHODS: DESIGN AND POPULATION:We carried out a blinded structured review of a random sample of 363 Randomised Controlled Trials (RCTs) carried out on human beings, and published in high impact factor medica...

journal_title：BMC medical research methodology

authors： Bernal-Delgado E,Fisher ES

更新日期：2008-03-27 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:This study aimed to investigate whether awareness of being monitored by an accelerometer has an effect on physical activity in young people. METHODS:Eighty healthy participants aged 10-18 years were randomized between blinded and nonblinded groups. The blinded participants were informed that we were testing...

journal_title：BMC medical research methodology

authors： Vanhelst J,Béghin L,Drumez E,Coopman S,Gottrand F

更新日期：2017-07-11 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:Multiple imputation (MI) provides an effective approach to handle missing covariate data within prognostic modelling studies, as it can properly account for the missing data uncertainty. The multiply imputed datasets are each analysed using standard prognostic modelling techniques to obtain the estimates of ...

journal_title：BMC medical research methodology

authors： Marshall A,Altman DG,Holder RL,Royston P

更新日期：2009-07-28 00:00:00

abstract：BACKGROUND:Crowding in the emergency department (ED) is associated with increased mortality, increased treatment cost, and reduced quality of care. Crowding arises when demand exceed resources in the ED and a first sign may be increasing waiting time. We aimed to quantify predictors for departure from the ED, and relat...

journal_title：BMC medical research methodology

authors： Eiset AH,Kirkegaard H,Erlandsen M

更新日期：2019-03-29 00:00:00

abstract：BACKGROUND:Data on lifetime exposures are often self-reported in epidemiologic studies, sometimes many years after the relevant age. Validity of self-reported data is usually inferred from their agreement with measured values, but few studies directly quantify the likely effects of reporting errors in body size and rep...

journal_title：BMC medical research methodology

authors： Cairns BJ,Liu B,Clennell S,Cooper R,Reeves GK,Beral V,Kuh D

更新日期：2011-01-17 00:00:00