Bmc Med Res Methodol
-
Bmc Med Res Methodol · Sep 2012
Simulation evaluation of statistical properties of methods for indirect and mixed treatment comparisons.
Indirect treatment comparison (ITC) and mixed treatment comparisons (MTC) have been increasingly used in network meta-analyses. This simulation study comprehensively investigated statistical properties and performances of commonly used ITC and MTC methods, including simple ITC (the Bucher method), frequentist and Bayesian MTC methods. ⋯ The available methods for indirect and mixed treatment comparisons have different advantages and limitations, depending on whether data analysed satisfies underlying assumptions. To choose the most valid statistical methods for research synthesis, an appropriate assessment of primary studies included in evidence network is required.
-
Bmc Med Res Methodol · Aug 2012
Bureaucracy stifles medical research in Britain: a tale of three trials.
Recent developments aiming to standardise and streamline processes of gaining the necessary approvals to carry out research in the National Health Service (NHS) in the United Kingdom (UK), have resulted in lengthy and costly delays. The national UK governmental Department of Health's Research Governance Framework (RGF) for Health and Social Care requires that appropriate checks be conducted before research involving human participants, their organs, tissues or data can commence in the NHS. As a result, medical research has been subjected to increased regulation and governance, with the requirement for approvals from numerous regulatory and monitoring bodies. In addition, the processes and outcomes of the attribution of costs in NHS research have caused additional difficulties for researchers. The purpose of this paper is to illustrate, through three trial case studies, the difficulties encountered during the set-up and recruitment phases of these trials, related to gaining the necessary ethical and governance approvals and applying for NHS costs to undertake and deliver the research. ⋯ Whilst the three trials encountered a variety of challenges, there were common issues. The processes for gaining approvals were overly complex and differed between sites and UK countries; guidance about processes was unclear; and information regarding how to define and claim NHS costs for undertaking the research was inconsistent. The competitive advantage of a publicly funded, open access health system for undertaking health services research and clinical trials within the UK has been outweighed in recent years by stifling bureaucratic structures and processes for governance of research. The recommendations of the Academy of Medical Sciences are welcomed, and the effects of their implementation are awaited with interest.
-
Bmc Med Res Methodol · Jul 2012
Analyzing repeated data collected by mobile phones and frequent text messages. An example of low back pain measured weekly for 18 weeks.
Repeated data collection is desirable when monitoring fluctuating conditions. Mobile phones can be used to gather such data from large groups of respondents by sending and receiving frequently repeated short questions and answers as text messages.The analysis of repeated data involves some challenges. Vital issues to consider are the within-subject correlation, the between measurement occasion correlation and the presence of missing values.The overall aim of this commentary is to describe different methods of analyzing repeated data. It is meant to give an overview for the clinical researcher in order for complex outcome measures to be interpreted in a clinically meaningful way. ⋯ We have illustrated several ways of analysing repeated measures with both traditional analytic approaches using standard statistical packages, as well as recently developed statistical methods that will utilize all the vital features inherent in the data.
-
Bmc Med Res Methodol · Jul 2012
How pragmatic or explanatory is the randomized, controlled trial? The application and enhancement of the PRECIS tool to the evaluation of a smoking cessation trial.
Numerous explanatory randomized trials support the efficacy of chronic disease interventions, including smoking cessation treatments. However, there is often inadequate adoption of these interventions for various reasons, one being the limitation of generalizability of the explanatory studies in real-world settings. Randomized controlled trials can be rated as more explanatory versus pragmatic along 10 dimensions. Pragmatic randomized clinical trials generate more realistic estimates of effectiveness with greater relevance to clinical practice and for health resource allocation decisions. However, there is no clear method to scale each dimension during the trial design phase to ensure that the design matches the intended purpose of the study. ⋯ This addition to the PRECIS tool may assist other trial designers working with interdisciplinary co-investigators to rate their study design while building consensus.
-
Bmc Med Res Methodol · Jul 2012
Adjusting for under-identification of Aboriginal and/or Torres Strait Islander births in time series produced from birth records: using record linkage of survey data and administrative data sources.
Statistical time series derived from administrative data sets form key indicators in measuring progress in addressing disadvantage in Aboriginal and Torres Strait Islander populations in Australia. However, inconsistencies in the reporting of Indigenous status can cause difficulties in producing reliable indicators. External data sources, such as survey data, provide a means of assessing the consistency of administrative data and may be used to adjust statistics based on administrative data sources. ⋯ Record linkage of survey data to administrative data sets is useful to validate the quality of recording of demographic information in administrative data sources, and such information can be used to adjust for differential identification in administrative data.