Dichotomisation using a distributional approach when the outcome is skewed.

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:Recruitment to health research remains a major challenge. Innovation is required to meet policy commitments to help patients take part in health research. One innovation that may help meet those policy goals is the development of 'consent to contact' systems, where people give generic consent to be contacted...

journal_title：BMC medical research methodology

authors： Grady K,Gibson M,Bower P

更新日期：2019-10-22 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:A recent paper found that terminal digits of statistical values in Nature deviated significantly from an equiprobable distribution, indicating errors or inconsistencies in rounding. This finding, as well as the discovery that a large percentage of p values were inconsistent with reported test statistics, led...

journal_title：BMC medical research methodology

authors： Jeng M

更新日期：2006-09-13 00:00:00

abstract：BACKGROUND:Diagnostic tests are performed in a subset of the population who are at higher risk, resulting in undiagnosed cases among those who do not receive the test. This poses a challenge for estimating the prevalence of the disease in the study population, and also for studying the risk factors for the disease. ME...

journal_title：BMC medical research methodology

authors： Zhang N,Cheng S,Ambroggio L,Florin TA,Macaluso M

更新日期：2017-12-12 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: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 lack of suitable and reliable scales to measure self-reported health and health behaviour among people with intellectual disabilities (ID) is an important methodological challenge in health research. This study, which was undertaken together with co-researchers with ID, explores possibilities for self-re...

journal_title：BMC medical research methodology

authors： Vlot-van Anrooij K,Tobi H,Hilgenkamp TIM,Leusink GL,Naaldenberg J

更新日期：2018-07-16 00:00:00

abstract：BACKGROUND:Outcomes in observational studies may not best estimate those expected in the HIV vaccine efficacy trials. We compared retention in Simulated HIV Vaccine Efficacy Trials (SiVETs) and observational cohorts drawn from two key populations in Uganda. METHODS:Two SiVETs were nested within two observational cohor...

journal_title：BMC medical research methodology

authors： Abaasa A,Todd J,Nash S,Mayanja Y,Kaleebu P,Fast PE,Price M

更新日期：2020-02-12 00:00:00

abstract：BACKGROUND:Posttraumatic growth is the positive change resulting from traumatic experiences and is typically assessed with retrospective measures like the Posttraumatic Growth Inventory (PTGI). The PTGI was designed to include reference to a specific traumatic event, making it difficult to implement, without change, in...

journal_title：BMC medical research methodology

authors： Kaur N,Porter B,LeardMann CA,Tobin LE,Lemus H,Luxton DD,Millennium Cohort Study Team.

更新日期：2017-04-20 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: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:Greater transparency and, in particular, sharing of patient-level data for further scientific research is an increasingly important topic for the pharmaceutical industry and other organisations who sponsor and conduct clinical trials as well as generally in the interests of patients participating in studies....

journal_title：BMC medical research methodology

authors： Tucker K,Branson J,Dilleen M,Hollis S,Loughlin P,Nixon MJ,Williams Z

更新日期：2016-07-08 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:Cross-cultural research with patient-reported outcomes measures (PROMs) assumes that the PROM in the target language will measure the same construct in the same way as the PROM in the source language. Yet translation methods are rarely used to qualitatively maximise construct equivalence or to describe the i...

journal_title：BMC medical research methodology

authors： Hawkins M,Cheng C,Elsworth GR,Osborne RH

更新日期：2020-05-26 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: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

abstract：BACKGROUND:The mechanisms and pathways to impacts from public health research in the UK have not been widely studied. Through the lens of one funder (NIHR), our aims are to map the diversity of public health research, in terms of funding mechanisms, disciplinary contributions, and public health impacts, identify exampl...

journal_title：BMC medical research methodology

authors： Boulding H,Kamenetzky A,Ghiga I,Ioppolo B,Herrera F,Parks S,Manville C,Guthrie S,Hinrichs-Krapels S

更新日期：2020-02-19 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:Chemotherapy is expected to reduce cancer deaths (CD), while possibly being harmful in terms of non-cancer deaths (NCD) because of toxicity. Peto's log-rank test is popular in the medical literature, but its operating characteristics are barely known. We compared this test to the most common ones in the stat...

journal_title：BMC medical research methodology

authors： Rotolo F,Michiels S

更新日期：2014-05-29 00:00:00

abstract：BACKGROUND:Evidence-based health care is informed by results of randomized clinical trials (RCTs) and their syntheses in meta-analyses. When the trial outcomes measured are not clearly described in trial publications, knowledge synthesis, translation, and decision-making may be impeded. While heterogeneity in outcomes ...

journal_title：BMC medical research methodology

authors： Monsour A,Mew EJ,Patel S,Chee-A-Tow A,Saeed L,Santos L,Courtney DB,Watson PN,Monga S,Szatmari P,Offringa M,Butcher NJ

更新日期：2020-05-25 00:00:00

abstract：BACKGROUND:The most commonly used survey methods are self-administered questionnaires, telephone interviews, and a mixture of both. But until now evidence out of randomised controlled trials as to whether patient responses differ depending on the survey mode is lacking. Therefore this study assessed whether patient res...

journal_title：BMC medical research methodology

authors： Lungenhausen M,Lange S,Maier C,Schaub C,Trampisch HJ,Endres HG

更新日期：2007-11-22 00:00:00

abstract：BACKGROUND:Given an observed test statistic and its degrees of freedom, one may compute the observed P value with most statistical packages. It is unknown to what extent test statistics and P values are congruent in published medical papers. METHODS:We checked the congruence of statistical results reported in all the ...

journal_title：BMC medical research methodology

authors： García-Berthou E,Alcaraz C

更新日期：2004-05-28 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: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:When conducting a meta-analysis of a continuous outcome, estimated means and standard deviations from the selected studies are required in order to obtain an overall estimate of the mean effect and its confidence interval. If these quantities are not directly reported in the publications, they must be estima...

journal_title：BMC medical research methodology

authors： Kwon D,Reis IM

更新日期：2015-08-12 00:00:00

abstract：BACKGROUND:We developed and validated an automated database case definition for diabetes in children and youth to facilitate pharmacoepidemiologic investigations of medications and the risk of diabetes. METHODS:The present study was part of an in-progress retrospective cohort study of antipsychotics and diabetes in Te...

journal_title：BMC medical research methodology

authors： Bobo WV,Cooper WO,Stein CM,Olfson M,Mounsey J,Daugherty J,Ray WA

更新日期：2012-08-24 00:00:00

abstract：BACKGROUND:Growth Mixture Modeling (GMM) is commonly used to group individuals on their development over time, but convergence issues and impossible values are common. This can result in unreliable model estimates. Constraining variance parameters across classes or over time can solve these issues, but can also serious...

journal_title：BMC medical research methodology

authors： Sijbrandij JJ,Hoekstra T,Almansa J,Peeters M,Bültmann U,Reijneveld SA

更新日期：2020-11-12 00:00:00

abstract：BACKGROUND:The intraclass correlation coefficient (ICC) is widely used in biomedical research to assess the reproducibility of measurements between raters, labs, technicians, or devices. For example, in an inter-rater reliability study, a high ICC value means that noise variability (between-raters and within-raters) is...

journal_title：BMC medical research methodology

authors： Ionan AC,Polley MY,McShane LM,Dobbin KK

更新日期：2014-11-22 00:00:00

abstract：BACKGROUND:Compliance is a critical issue for parental questionnaires in school based epidemiological surveys and high compliance is difficult to achieve. The objective of this study was to determine trends and factors associated with parental questionnaire compliance during respiratory health surveys of school childre...

journal_title：BMC medical research methodology

authors： Koshy G,Brabin BJ

更新日期：2012-04-20 00:00:00