Comparing survival curves based on medians.

abstract：BACKGROUND:Disease registers aim to collect information about all instances of a disease or condition in a defined population of individuals. Traditionally methods of operating disease registers have required that notifications of cases be identified by unique identifiers such as social security number or national iden...

journal_title：BMC medical research methodology

authors： Churches T

更新日期：2003-01-06 00:00:00

abstract：BACKGROUND:Network meta-analysis can be used to combine results from several randomized trials involving more than two treatments. Potential inconsistency among different types of trial (designs) differing in the set of treatments tested is a major challenge, and application of procedures for detecting and locating inc...

journal_title：BMC medical research methodology

authors： Piepho HP

更新日期：2014-05-10 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: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:The International Cancer Benchmarking Partnership aims to study international differences in cancer survival and the possible causes. Participating countries are Australia, Canada, Norway, Sweden, Denmark and the UK and a particular focus area is differences in awareness and beliefs about cancer. In this con...

journal_title：BMC medical research methodology

authors： Hvidberg L,Pedersen AF,Wulff CN,Carlsen AH,Vedsted P

更新日期：2017-04-26 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:Randomised controlled trials (RCTs) are the gold standard for evidence-based practice. However, RCTs can have limitations. For example, translation of findings into practice can be limited by design features, such as inclusion criteria, not accurately reflecting clinical populations. In addition, it is expen...

journal_title：BMC medical research methodology

authors： Lemanska A,Byford RC,Cruickshank C,Dearnaley DP,Ferreira F,Griffin C,Hall E,Hinton W,de Lusignan S,Sherlock J,Faithfull S

更新日期：2020-07-25 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: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:Interventions in occupational health often target worksites rather than individuals. The objective of this paper is to describe the (lack of) stability in units of analysis in occupational health and safety intervention projects directed toward worksites. METHODS:A case study approach is used to describe na...

journal_title：BMC medical research methodology

authors： Olsen O,Albertsen K,Nielsen ML,Poulsen KB,Gron SM,Brunnberg HL

更新日期：2008-06-13 00:00:00

abstract：BACKGROUND:Studies in both paediatric and psychiatric settings often experience problems in recruitment. This can compromise the ability of the study to recruit to target, meaning studies are potentially underpowered. It can also result in a biased sample if a non-representative group are selectively recruited. Recruit...

journal_title：BMC medical research methodology

authors： Loades ME,Smith L,Higson-Sweeney N,Beasant L,Stallard P,Kessler D,Crawley E

更新日期：2019-04-27 00:00:00

abstract：BACKGROUND:Due to early colonoscopy for some participants, interval-censored observations can be introduced into the data of a colorectal polyp prevention trial. The censoring could be dependent of risk of recurrence if the reasons of having early colonoscopy are associated with recurrence. This can complicate estimati...

journal_title：BMC medical research methodology

authors： Hsu CH,Long Q,Alberts DS

更新日期：2009-09-29 00:00:00

abstract：BACKGROUND:The aim of this study was to examine the relationship between mortality and statin adherence using two different approaches to adherence measurement (summary versus repeated-measures). METHODS:A retrospective cohort study was conducted using administrative data from Saskatchewan, Canada between 1994 and 200...

journal_title：BMC medical research methodology

authors： Alsabbagh MW,Eurich D,Lix LM,Wilson TW,Blackburn DF

更新日期：2017-04-20 00:00:00

abstract：BACKGROUND:The development of risk prediction models is of increasing importance in medical research - their use in practice, however, is rare. Among other reasons this might be due to the fact that thorough validation is often lacking. This study focuses on two Bayesian approaches of how to validate a prediction rule ...

journal_title：BMC medical research methodology

authors： Held U,Bové DS,Steurer J,Held L

更新日期：2012-07-20 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: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 longitudinal studies where subjects experience recurrent incidents over a period of time, such as respiratory infections, fever or diarrhea, statistical methods are required to take into account the within-subject correlation. METHODS:For repeated events data with censored failure, the independent increm...

journal_title：BMC medical research methodology

authors： Villegas R,Julià O,Ocaña J

更新日期：2013-07-24 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: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:Navigating the world of qualitative thematic analysis can be challenging. This is compounded by the fact that detailed descriptions of methods are often omitted from qualitative discussions. While qualitative research methodologies are now mature, there often remains a lack of fine detail in their descriptio...

journal_title：BMC medical research methodology

authors： Roberts K,Dowell A,Nie JB

更新日期：2019-03-28 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:Aboriginal and Torres Strait Islander peoples are under-reported in administrative health datasets in NSW, Australia. Correct reporting of Aboriginal and Torres Strait Islander peoples is essential to measure the effectiveness of policies and programmes aimed at reducing the health disadvantage experienced b...

journal_title：BMC medical research methodology

authors： Taylor LK,Bentley J,Hunt J,Madden R,McKeown S,Brandt P,Baker D

更新日期：2012-07-02 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:Video stimulated recall (VSR) is a method of enhancing participants' accounts of the consultation using a video recording of the event to encourage and prompt recall in a post consultation interview. VSR is used in education and education research, and to a lesser extent in medical and nursing research. Litt...

journal_title：BMC medical research methodology

authors： Paskins Z,McHugh G,Hassell AB

更新日期：2014-08-30 00:00:00

abstract：BACKGROUND:In prognostic studies model instability and missing data can be troubling factors. Proposed methods for handling these situations are bootstrapping (B) and Multiple imputation (MI). The authors examined the influence of these methods on model composition. METHODS:Models were constructed using a cohort of 58...

journal_title：BMC medical research methodology

authors： Vergouw D,Heymans MW,Peat GM,Kuijpers T,Croft PR,de Vet HC,van der Horst HE,van der Windt DA

更新日期：2010-09-17 00:00:00

abstract：BACKGROUND:Joint models of longitudinal and time-to-event data are increasingly used to perform individual dynamic prediction of a risk of event. However the difficulty to perform inference in nonlinear models and to calculate the distribution of individual parameters has long limited this approach to linear mixed-effe...

journal_title：BMC medical research methodology

authors： Desmée S,Mentré F,Veyrat-Follet C,Sébastien B,Guedj J

更新日期：2017-07-17 00:00:00

abstract：BACKGROUND:The likelihood ratio function (LR), the ratio of conditional probabilities of obtaining a specific marker value among those with the event of interest over those without, provides an easily interpretable way to quantify the update of the risk prediction due to the knowledge of the marker value. The LR has be...

journal_title：BMC medical research methodology

authors： Smith AM,Christodouleas JP,Hwang WT

更新日期：2019-05-22 00:00:00

abstract：BACKGROUND:Claims databases are generally considered inadequate for obesity research due to suboptimal capture of body mass index (BMI) measurements. This might not be true for bariatric surgery because of reimbursement requirements and changes in coding systems. We assessed the availability and validity of claims-base...

journal_title：BMC medical research methodology

authors： Li X,Lewis KH,Callaway K,Wharam JF,Toh S

更新日期：2020-09-07 00:00:00

abstract：BACKGROUND:When multiple endpoints are of interest in evidence synthesis, a multivariate meta-analysis can jointly synthesise those endpoints and utilise their correlation. A multivariate random-effects meta-analysis must incorporate and estimate the between-study correlation (rhoB). METHODS:In this paper we assess ma...

journal_title：BMC medical research methodology

authors： Riley RD,Abrams KR,Sutton AJ,Lambert PC,Thompson JR

更新日期：2007-01-12 00:00:00

abstract：BACKGROUND:Mean arterial pressure (MAP), bispectral index (BIS), and minimum alveolar concentration (MAC) represent valuable, yet dynamic intraoperative monitoring variables. They provide information related to poor outcomes when considered together, however their collective behavior across time has not been characteri...

journal_title：BMC medical research methodology

authors： Schnetz MP,Hochheiser HS,Danks DJ,Landsittel DP,Vogt KM,Ibinson JW,Whitehurst SL,McDermott SP,Duque MG,Kaynar AM

更新日期：2019-01-14 00:00:00