Empirical study of correlated survival times for recurrent events with proportional hazards margins and the effect of correlation and censoring.

abstract：BACKGROUND:Small number of clusters and large variation of cluster sizes commonly exist in cluster-randomized trials (CRTs) and are often the critical factors affecting the validity and efficiency of statistical analyses. F tests are commonly used in the generalized linear mixed model (GLMM) to test intervention effect...

journal_title：BMC medical research methodology

authors： Li P,Redden DT

更新日期：2015-04-23 00:00:00

abstract：BACKGROUND:This research aims to explore an identified gap in implementation science methodology, that is, how to assess context in implementation research. Context is among the strongest influences on implementation success but is a construct that is poorly understood and reported within the literature. Consequently, ...

journal_title：BMC medical research methodology

authors： Rogers L,De Brún A,McAuliffe E

更新日期：2020-06-15 00:00:00

abstract：BACKGROUND:The choice between paper data collection methods and electronic data collection (EDC) methods has become a key question for clinical researchers. There remains a need to examine potential benefits, efficiencies, and innovations associated with an EDC system in a multi-center medical record review study. MET...

journal_title：BMC medical research methodology

authors： Thwin SS,Clough-Gorr KM,McCarty MC,Lash TL,Alford SH,Buist DS,Enger SM,Field TS,Frost F,Wei F,Silliman RA

更新日期：2007-06-18 00:00:00

abstract：BACKGROUND:Mediation is an important issue considered in the behavioral, medical, and social sciences. It addresses situations where the effect of a predictor variable X on an outcome variable Y is explained to some extent by an intervening, mediator variable M. Methods for addressing mediation have been available for ...

journal_title：BMC medical research methodology

authors： Knafl GJ,Knafl KA,Grey M,Dixon J,Deatrick JA,Gallo AM

更新日期：2017-03-21 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

abstract：BACKGROUND:Plasma cell dyscrasias (PCD) are a spectrum of disorders resulting from the clonal expansion of plasma cells, ranging from the pre-malignant condition monoclonal gammopathy of undetermined significance (MGUS) to multiple myeloma (MM). MM generates a significant burden of disease on the community and it is pr...

journal_title：BMC medical research methodology

authors： Bergin K,Moore E,McQuilten Z,Wood E,Augustson B,Blacklock H,Ho J,Horvath N,King T,McNeil J,Mollee P,Quach H,Reid CM,Rosengarten B,Walker P,Spencer A

更新日期：2016-11-09 00:00:00

abstract：BACKGROUND:It is widely recognised that the pursuit of sustainable development cannot be accomplished without addressing inequality, or observed differences between subgroups of a population. Monitoring health inequalities allows for the identification of health topics where major group differences exist, dimensions of...

journal_title：BMC medical research methodology

authors： Hosseinpoor AR,Nambiar D,Schlotheuber A,Reidpath D,Ross Z

更新日期：2016-10-19 00:00:00

abstract：BACKGROUND:Methods for describing one's confidence in the available evidence are useful for end-users of evidence reviews. Analysts inevitably make judgments about the quality, quantity consistency, robustness, and magnitude of effects observed in the studies identified. The subjectivity of these judgments in several a...

journal_title：BMC medical research methodology

authors： Treadwell JR,Tregear SJ,Reston JT,Turkelson CM

更新日期：2006-10-19 00:00:00

abstract：BACKGROUND:To assess cross-cultural validity between Dutch and English versions of the FVQ_CYP, a patient-reported outcome measure developed in the United Kingdom (UK) for children and adolescents with (severe) visual impairment or blindness (VI for brevity) to measure functional vision. METHODS:The 36-item FVQ_CYP wa...

journal_title：BMC medical research methodology

authors： Elsman EBM,Tadić V,Peeters CFW,van Rens GHMB,Rahi JS,van Nispen RMA

更新日期：2019-12-03 00:00:00

abstract：BACKGROUND:Sero- prevalence studies often have a problem of missing data. Few studies report the proportion of missing data and even fewer describe the methods used to adjust the results for missing data. The objective of this review was to determine the analytical methods used for analysis in HIV surveys with missing ...

journal_title：BMC medical research methodology

authors： Mosha NR,Aluko OS,Todd J,Machekano R,Young T

更新日期：2020-03-14 00:00:00

abstract：BACKGROUND:Discrete Choice Experiments (DCEs) are increasingly used in studies in healthcare research but there is still little empirical evidence for the predictive value of these hypothetical situations in similar real life circumstances. The aim of this paper is to compare the stated preferences in a DCE and the acc...

journal_title：BMC medical research methodology

authors： Lambooij MS,Harmsen IA,Veldwijk J,de Melker H,Mollema L,van Weert YW,de Wit GA

更新日期：2015-03-12 00:00:00

abstract：BACKGROUND:The Behavioral Risk Factor Surveillance System (BRFSS) is a network of health-related telephone surveys--conducted by all 50 states, the District of Columbia, and participating US territories-that receive technical assistance from CDC. Data users often aggregate BRFSS state samples for national estimates wit...

journal_title：BMC medical research methodology

authors： Iachan R,Pierannunzi C,Healey K,Greenlund KJ,Town M

更新日期：2016-11-15 00:00:00

abstract：BACKGROUND:Cluster randomised controlled trials (CRCTs) are frequently used in health service evaluation. Assuming an average cluster size, required sample sizes are readily computed for both binary and continuous outcomes, by estimating a design effect or inflation factor. However, where the number of clusters are fix...

journal_title：BMC medical research methodology

authors： Hemming K,Girling AJ,Sitch AJ,Marsh J,Lilford RJ

更新日期：2011-06-30 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:Controlling the false discovery rate is important when testing multiple hypotheses. To enhance the detection capability of a false discovery rate control test, we applied the likelihood ratio-based multiple testing method in neuroimage data and compared the performance with the existing methods. METHODS:We ...

journal_title：BMC medical research methodology

authors： Lee D,Kang H,Kim E,Lee H,Kim H,Kim YK,Lee Y,Lee DS

更新日期：2015-01-30 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:When discussing results medical research articles often tear substantive and statistical (methodical) contributions apart, just as if both were independent. Consequently, reasoning on bias tends to be vague, unclear and superficial. This can lead to over-generalized, too narrow and misleading conclusions, es...

journal_title：BMC medical research methodology

authors： Höfler M,Venz J,Trautmann S,Miller R

更新日期：2018-04-17 00:00:00

abstract：BACKGROUND:The "real" effect size of a medical therapy is constant over time. In contrast, the effect size reported in randomised controlled trials (RCTs) may change over time because the sum of all kinds of bias influencing the reported effectiveness is not necessarily constant. As this would affect the validity of me...

journal_title：BMC medical research methodology

authors： Gehr BT,Weiss C,Porzsolt F

更新日期：2006-05-11 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: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:Retaining participants in cohort studies with multiple follow-up waves is difficult. Commonly, researchers are faced with the problem of missing data, which may introduce biased results as well as a loss of statistical power and precision. The STROBE guidelines von Elm et al. (Lancet, 370:1453-1457, 2007); V...

journal_title：BMC medical research methodology

authors： Karahalios A,Baglietto L,Carlin JB,English DR,Simpson JA

更新日期：2012-07-11 00:00:00

abstract：BACKGROUND:Syntheses of qualitative studies can inform health policy, services and our understanding of patient experience. Meta-ethnography is a systematic seven-phase interpretive qualitative synthesis approach well-suited to producing new theories and conceptual models. However, there are concerns about the quality ...

journal_title：BMC medical research methodology

authors： France EF,Ring N,Thomas R,Noyes J,Maxwell M,Jepson R

更新日期：2014-11-19 00:00:00

abstract：BACKGROUND:Patient-reported outcomes (PRO) are important as endpoints in clinical trials and epidemiological studies. Guidelines for the development of PRO instruments and analysis of PRO data have emphasized the need to report methods used for sample size planning. The Raschpower procedure has been proposed for sample...

journal_title：BMC medical research methodology

authors： Blanchin M,Guilleux A,Perrot B,Bonnaud-Antignac A,Hardouin JB,Sébille V

更新日期：2015-03-15 00:00:00

abstract：BACKGROUND:Action research (AR) and randomized controlled trials (RCTs) are usually considered to be theoretically and practically incompatible. However, we argue that their respective strengths and weaknesses can be complementary. We illustrate our argument from a recent study assessing the effect of telemonitoring on...

journal_title：BMC medical research methodology

authors： Day K,Kenealy TW,Sheridan NF

更新日期：2016-06-08 00:00:00

abstract：BACKGROUND:In the era of evidence based medicine, with systematic reviews as its cornerstone, adequate quality assessment tools should be available. There is currently a lack of a systematically developed and evaluated tool for the assessment of diagnostic accuracy studies. The aim of this project was to combine empiri...

journal_title：BMC medical research methodology

authors： Whiting P,Rutjes AW,Reitsma JB,Bossuyt PM,Kleijnen J

更新日期：2003-11-10 00:00:00

abstract：BACKGROUND:A key component of the implementation process is identifying potential barriers and facilitators that need to be addressed. The Theoretical Domains Framework (TDF) is one of the most commonly used frameworks for this purpose. When applying the TDF, it is critical to understand the context in which behaviours...

journal_title：BMC medical research methodology

authors： Etherington N,Rodrigues IB,Giangregorio L,Graham ID,Hoens AM,Kasperavicius D,Kelly C,Moore JE,Ponzano M,Presseau J,Sibley KM,Straus S

更新日期：2020-06-26 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:This article describes the design and baseline sample of a single-site trial comparing Individual Placement and Support (IPS) supported employment delivered within a Veterans Health Administration (VHA) primary care Patient Aligned Care Team (PACT) to treatment-as-usual vocational rehabilitation (TAU-VR) tha...

journal_title：BMC medical research methodology

authors： Davis LL,Blansett CM,Mumba MN,MacVicar D,Toscano R,Pilkinton P,Gay W,Bartolucci A

更新日期：2020-02-17 00:00:00

abstract：BACKGROUND:Physical activity is an important determinant of health. Walking is the most common physical activity performed by adults and the presence of sidewalks along roads is a determinant of walking. Geographic information systems (GIS) can be used to measure sidewalks; however, GIS sidewalk data are difficult to a...

journal_title：BMC medical research methodology

authors： Janssen I,Rosu A

更新日期：2012-03-29 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