12 Result(s)

Article

Dynamic updating of clinical survival prediction models in a changing environment

Over time, the performance of clinical prediction models may deteriorate due to changes in clinical management, data quality, disease risk and/or patient mix. Such prediction models must be updated in order to...

Kamaryn T. Tanner, Ruth H. Keogh… in Diagnostic and Prognostic Research (2023)

Article

Estimating distribution of length of stay in a multi-state model conditional on the pathway, with an application to patients hospitalised with Covid-19

Multi-state models are used to describe how individuals transition through different states over time. The distribution of the time spent in different states, referred to as ‘length of stay’, is often of inter...

Ruth H. Keogh, Karla Diaz-Ordaz, Nicholas P. Jewell… in Lifetime Data Analysis (2023)

Article

A comparison of covariate adjustment approaches under model misspecification in individually randomized trials

Adjustment for baseline covariates in randomized trials has been shown to lead to gains in power and can protect against chance imbalances in covariates. For continuous covariates, there is a risk that the the...

Mia S. Tackney, Tim Morris, Ian White, Clemence Leyrat, Karla Diaz-Ordaz… in Trials (2023)

Article

Comparison of methods for predicting COVID-19-related death in the general population using the OpenSAFELY platform

Obtaining accurate estimates of the risk of COVID-19-related death in the general population is challenging in the context of changing levels of circulating infection.

Elizabeth J. Williamson, John Tazare… in Diagnostic and Prognostic Research (2022)

Article

Importance of patient bed pathways and length of stay differences in predicting COVID-19 hospital bed occupancy in England

Predicting bed occupancy for hospitalised patients with COVID-19 requires understanding of length of stay (LoS) in particular bed types. LoS can vary depending on the patient’s “bed pathway” - the sequence of ...

Quentin J. Leclerc, Naomi M. Fuller, Ruth H. Keogh… in BMC Health Services Research (2021)

Article

Increased mortality in community-tested cases of SARS-CoV-2 lineage B.1.1.7

SARS-CoV-2 lineage B.1.1.7, a variant that was first detected in the UK in September 2020¹, has spread to multiple countries worldwide. Several studies have established that B.1.1.7 is more transmissible than pre...

Nicholas G. Davies, Christopher I. Jarvis, W. John Edmunds, Nicholas P. Jewell… in Nature (2021)

Article

Co** with Persistent Pain, Effectiveness Research into Self-management (COPERS): statistical analysis plan for a randomised controlled trial

The Co** with Persistent Pain, Effectiveness Research into Self-management (COPERS) trial assessed whether a group-based self-management course is effective in reducing pain-related disability in participant...

Brennan C Kahan, Karla Diaz-Ordaz, Kate Homer, Dawn Carnes, Martin Underwood… in Trials (2014)

Article

A systematic review of cluster randomised trials in residential facilities for older people suggests how to improve quality

Previous reviews of cluster randomised trials have been critical of the quality of the trials reviewed, but none has explored determinants of the quality of these trials in a specific field over an extended pe...

Karla Diaz-Ordaz, Robert Froud, Bart Sheehan… in BMC Medical Research Methodology (2013)

Article

Comparing diagnostic tests and biomarkers: trials in people with discordant test results

Richard Hooper, Karla Díaz-Ordaz, Andrea Takeda, Khalid Khan in Trials (2011)