Multiple imputation for estimating hazard ratios and predictive abilities in case-cohort surveys.

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: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:Postal questionnaires are widely used to collect outcome data on participants. However, a poor response to questionnaires will reduce the statistical power of the study and may introduce bias. A meta analysis of ten trials offering study results, largely in the fields of education and marketing, was shown to...

journal_title：BMC medical research methodology

authors： Cockayne S,Torgerson DJ

更新日期：2005-10-26 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:The study design and protocol that underpin a randomised controlled trial (RCT) are critical for the ultimate success of the trial. Although RCTs are considered the gold standard for research, there are multiple threats to their validity such as participant recruitment and retention, identifying a meaningful...

journal_title：BMC medical research methodology

authors： Hall CL,Brown S,James M,Martin JL,Brown N,Selby K,Clarke J,Williams L,Sayal K,Hollis C,Groom MJ

更新日期：2019-06-18 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: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: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: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:Randomized controlled trials are the gold-standard for clinical trials. However, randomization is not always feasible. In this article we propose a prospective and adaptive matched case-control trial design assuming that a control group already exists. METHODS:We propose and discuss an interim analysis step...

journal_title：BMC medical research methodology

authors： Weber D,Uhlmann L,Schönenberger S,Kieser M

更新日期：2019-07-16 00:00:00

abstract：BACKGROUND:Studies examining incident heart failure (HF) have been limited to select populations. To examine incident HF with broader generalizability, there is need to assemble a HF-free cohort using a geographically-diverse sample. We aimed to develop and validate a simple medication-based strategy for assembling a H...

journal_title：BMC medical research methodology

authors： Goyal P,Mefford MT,Chen L,Sterling MR,Durant RW,Safford MM,Levitan EB

更新日期：2020-03-04 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:Defeat and entrapment have been shown to be of central relevance to the development of different disorders. However, it remains unclear whether they represent two distinct constructs or one overall latent variable. One reason for the unclarity is that traditional factor analytic techniques have trouble estim...

journal_title：BMC medical research methodology

authors： Forkmann T,Teismann T,Stenzel JS,Glaesmer H,de Beurs D

更新日期：2018-01-25 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:Various papers have addressed pros and cons of the stepped wedge cluster randomized trial design (SWD). However, some issues have not or only limitedly been addressed. Our aim was to provide a comprehensive overview of all merits and limitations of the SWD to assist researchers, reviewers and medical ethics ...

journal_title：BMC medical research methodology

authors： de Hoop E,van der Tweel I,van der Graaf R,Moons KG,van Delden JJ,Reitsma JB,Koffijberg H

更新日期：2015-10-30 00:00:00

abstract：BACKGROUND:Multi-centre randomized controlled clinical trials play an important role in modern evidence-based medicine. Advantages of collecting data from more than one site are numerous, including accelerated recruitment and increased generalisability of results. Mixed models can be applied to account for potential cl...

journal_title：BMC medical research methodology

authors： Harden M,Friede T

更新日期：2018-11-29 00:00:00

abstract：BACKGROUND:Systematic reviews (SRs) must be of high quality. The purpose of our research was to compare the methodological and reporting quality of original versus updated Cochrane SRs to determine whether updating had improved these two quality dimensions. METHODS:We identified updated Cochrane SRs published in issue...

journal_title：BMC medical research methodology

authors： Shea B,Boers M,Grimshaw JM,Hamel C,Bouter LM

更新日期：2006-06-13 00:00:00

abstract：BACKGROUND:Nowadays, more and more clinical scales consisting in responses given by the patients to some items (Patient Reported Outcomes - PRO), are validated with models based on Item Response Theory, and more specifically, with a Rasch model. In the validation sample, presence of missing data is frequent. The aim of...

journal_title：BMC medical research methodology

authors： Hardouin JB,Conroy R,Sébille V

更新日期：2011-07-14 00:00:00

abstract：BACKGROUND:Polypharmacy can be either beneficial or harmful to children. We conducted a scoping review to examine the concept of pediatric polypharmacy: its definition, prevalence, extent and gaps in research. In this manuscript, we report our transdisciplinary scoping review methodology. METHODS:After establishing a ...

journal_title：BMC medical research methodology

authors： Bakaki PM,Staley J,Liu R,Dawson N,Golchin N,Horace A,Johnson H,Waldron J,Winterstein A,Kleinman LC,Bolen SD

更新日期：2018-10-04 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:Sleeping under a long-lasting insecticidal net (LLIN) is recommended for all pregnant women in sub-Saharan Africa, due to the high prevalence of malaria infection and its associated complications in the region. Despite this, LLIN use has still remained sub-optimal among pregnant women in Maiduguri, Nigeria. ...

journal_title：BMC medical research methodology

authors： Balami AD,Said SM,Zulkefli NAM,Bachok N,Balami EL

更新日期：2019-07-18 00:00:00

abstract：BACKGROUND:Multistate models have become increasingly useful to study the evolution of a patient's state over time in intensive care units ICU (e.g. admission, infections, alive discharge or death in ICU). In addition, in critically-ill patients, data come from different ICUs, and because observations are clustered int...

journal_title：BMC medical research methodology

authors： Liquet B,Timsit JF,Rondeau V

更新日期：2012-06-15 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:The health regulatory focus is an application of Higgins' regulatory focus theory to a health-specific context. It explains individual differences in health motivation, strategies, and behavior. Previous research found the Health Regulatory Focus Scale (HRFS) to be a reliable and valid measure for the constr...

journal_title：BMC medical research methodology

authors： Schmalbach B,Zenger M,Brähler E,Petrowski K

更新日期：2020-03-02 00:00:00

abstract：BACKGROUND:Biomarkers of exposures such as infection or environmental chemicals can be measured in small volumes of blood extracted from newborn dried blood spots (DBS) underscoring their potential utility for population-based research. However, few studies have evaluated the feasibility and utility of this resource; p...

journal_title：BMC medical research methodology

authors： Yeung EH,Louis GB,Lawrence D,Kannan K,McLain AC,Caggana M,Druschel C,Bell E

更新日期：2016-02-04 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: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: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:Competing risks are a common occurrence in survival analysis. They arise when a patient is at risk of more than one mutually exclusive event, such as death from different causes, and the occurrence of one of these may prevent any other event from ever happening. METHODS:There are two main approaches to mode...

journal_title：BMC medical research methodology

authors： Hinchliffe SR,Lambert PC

更新日期：2013-02-06 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