Error in statistical tests of error in statistical tests.

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:Evidence mapping describes the quantity, design and characteristics of research in broad topic areas, in contrast to systematic reviews, which usually address narrowly-focused research questions. The breadth of evidence mapping helps to identify evidence gaps, and may guide future research efforts. The Globa...

journal_title：BMC medical research methodology

authors： Bragge P,Clavisi O,Turner T,Tavender E,Collie A,Gruen RL

更新日期：2011-06-17 00:00:00

abstract：BACKGROUND:Cluster randomised trials with unequal sized clusters often have lower precision than with clusters of equal size. To allow for this, sample sizes are inflated by a modified version of the design effect for clustering. These inflation factors are valid under the assumption that randomisation is stratified by...

journal_title：BMC medical research methodology

authors： Martin JT,Hemming K,Girling A

更新日期：2019-06-14 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: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: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: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:Multilevel models for non-normal outcomes are widely used in medical and health sciences research. While methods for interpreting fixed effects are well-developed, methods to quantify and interpret random cluster variation and compare it with other sources of variation are less established. Random cluster va...

journal_title：BMC medical research methodology

authors： Glorioso TJ,Grunwald GK,Ho PM,Maddox TM

更新日期：2018-07-06 00:00:00

abstract：BACKGROUND:Functioning and disability are universal human experiences. However, our current understanding of functioning from a comprehensive perspective is limited. The development of the International Classification of Functioning, Disability and Health (ICF) on the one hand and recent developments in graphical model...

journal_title：BMC medical research methodology

authors： Kalisch M,Fellinghauer BA,Grill E,Maathuis MH,Mansmann U,Bühlmann P,Stucki G

更新日期：2010-02-11 00:00:00

abstract：BACKGROUND:The BSI-18 contains the three six-item scales somatization, depression, and anxiety as well as the Global Severity Index (GSI), including all 18 items. The BSI-18 is the latest and shortest of the multidimensional versions of the Symptom-Checklist 90-R, but its psychometric properties have not been sufficien...

journal_title：BMC medical research methodology

authors： Franke GH,Jaeger S,Glaesmer H,Barkmann C,Petrowski K,Braehler E

更新日期：2017-01-26 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: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:Collection of buccal cells from saliva for DNA extraction offers a less invasive and convenient alternative to venipuncture blood collection that may increase participation in genetic epidemiologic studies. However, dried blood spot collection, which is also a convenient method, offers a means of collecting ...

journal_title：BMC medical research methodology

authors： Bhatti P,Kampa D,Alexander BH,McClure C,Ringer D,Doody MM,Sigurdson AJ

更新日期：2009-11-13 00:00:00

abstract：BACKGROUND:The Health Care Module of the European Health Interview Survey (EHIS) is aimed to obtain comparable information on the use of inpatient and ambulatory care in all EU member states. In this study we assessed the validity of self-reported information on the use of health care, collected through this instrument...

journal_title：BMC medical research methodology

authors： Van der Heyden J,Charafeddine R,De Bacquer D,Tafforeau J,Van Herck K

更新日期：2016-08-16 00:00:00

abstract：BACKGROUND:A zero-inflated continuous outcome is characterized by occurrence of "excess" zeros that more than a single distribution can explain, with the positive observations forming a skewed distribution. Mixture models are employed for regression analysis of zero-inflated data. Moreover, for repeated measures zero-i...

journal_title：BMC medical research methodology

authors： Mahmud S,Lou WW,Johnston NW

更新日期：2010-06-14 00:00:00

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:The aim was to describe a strategy for recruitment of healthy volunteers (HV) to a randomized trial that assessed the efficacy of different telephone techniques to assist HV in performing cardiac massage for vital emergency. Participation in the randomized trial was not financially compensated, however HV we...

journal_title：BMC medical research methodology

authors： Luzurier Q,Damm C,Lion F,Daniel C,Pellerin L,Tavolacci MP

更新日期：2015-01-05 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：: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:A frequently used statistic for testing homogeneity in a meta-analysis of K independent studies is Cochran's Q. For a standard test of homogeneity the Q statistic is referred to a chi-square distribution with K-1 degrees of freedom. For the situation in which the effects of the studies are logarithms of odds...

journal_title：BMC medical research methodology

authors： Kulinskaya E,Dollinger MB

更新日期：2015-06-10 00:00:00

abstract：BACKGROUND:Evidence suggests that differences exist in physical activity (PA) participation among Culturally and Linguistically Diverse (CALD) children and adolescents. It is possible that these differences could be influenced by variations in measurement technique and instrument reliability. However, culturally sensit...

journal_title：BMC medical research methodology

authors： Strugnell C,Renzaho A,Ridley K,Burns C

更新日期：2011-08-25 00:00:00

abstract：BACKGROUND:Chronic Obstructive Pulmonary Disease (COPD) is currently the fifth leading cause of death in Australia, and there are marked differences in mortality trends between men and women. In this study, we have sought to model and forecast age related changes in COPD mortality over time for men and women separately...

journal_title：BMC medical research methodology

authors： Erbas B,Ullah S,Hyndman RJ,Scollo M,Abramson M

更新日期：2012-02-21 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:Postal self-completion questionnaires offer one of the least expensive modes of collecting patient based outcomes in health care research. The purpose of this review is to assess the efficacy of methods of increasing response to postal questionnaires in health care studies on patient populations. METHODS:Th...

journal_title：BMC medical research methodology

authors： Nakash RA,Hutton JL,Jørstad-Stein EC,Gates S,Lamb SE

更新日期：2006-02-23 00:00:00

abstract：BACKGROUND:Although a variety of instruments are available that capture stress experience, the assessment of chronic stress has been hindered by the lack of economical screening instruments. Recently, an English-language version of the Trier Inventory for Chronic Stress (TICS-EN) consisting of 57 items according to a s...

journal_title：BMC medical research methodology

authors： Petrowski K,Braehler E,Schmalbach B,Hinz A,Bastianon C,Ritz T

更新日期：2020-12-16 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:Meta-analysis typically involves combining the estimates from independent studies in order to estimate a parameter of interest across a population of studies. However, outliers often occur even under the random effects model. The presence of such outliers could substantially alter the conclusions in a meta-a...

journal_title：BMC medical research methodology

authors： Gumedze FN,Jackson D

更新日期：2011-02-16 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: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: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