Publications

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Treatment estimands in clinical trials of patients hospitalised for COVID-19: ensuring trials ask the right questions

Kahan BC, Morris TP, White IR, Tweed CD, Cro S, Dahly D, My Pham T, Esmail H, Babiker A, Carpenter JR.

This articles discusses challenges when defining estimands for trials of patients hospitalised for COVID-19 and makes suggestions for how estimands should be defined for key outcomes.

Publication Date:

BMC Medicine

How to design a pre-specified statistical analysis approach to limit p-hacking in clinical trials: the Pre-SPEC framework

Kahan BC, Forbes G, Cro S.

This article describes a five-point framework (the Pre-SPEC framework) for designing a pre-specified analysis approach that does not allow p-hacking. The framework is based on the principles in the SPIRIT and ICH-E9 guidelines and is intended to be used in conjunction with these guidelines to help investigators design the statistical analysis strategy for the trial’s primary outcome in the trial protocol.

Publication Date:

BMC Medicine

A four-step strategy for handling missing outcome data in randomised trials affected by a pandemic

Cro S, Morris TP, Kahan BC, Cornelius VR, Carpenter JR

This paper presents a four-step strategy for handling missing outcome data in the analysis of randomised trials that are ongoing during a pandemic. Settings where treatment effects for a ‘pandemic-free world’ and ‘world including a pandemic’ are of interest are considered.

Publication Date:

BMC Medical Research Methodology

Public availability and adherence to prespecified statistical analysis approaches was low in published randomized trials

Kahan BC, Ahmad T, Forbes G, Cro S.

This article reviews how often a prespecified statistical analysis approach was publicly available for randomized trials indexed in PubMed. For most published trials, there was insufficient information available to determine whether the results may be subject to p-hacking.

Publication Date:

Journal of Clinical Epidemiology

Understanding current practice, identifying barriers and exploring priorities for adverse event analysis in randomised controlled trials: an online, cross-sectional survey of statisticians from academia and industry

Phillips R, Cornelius V

This article reports the findings of a survey of statisticians that aimed to gain a better understanding of current adverse event analysis practices and explored statisticians' priorities, concerns and barriers when analysing adverse events.

Publication Date:

BMJ Open

Current approaches to handling rescue medication in asthma and eczema randomized controlled trials are inadequate: a systematic review

Chis Ster A, Cornelius V, Cro S

This review examines how rescue medication is defined, reported, and accounted for in randomized controlled trials in eczema and asthma populations. We found that while rescue medication is frequently permitted in trials alongside the treatment under evaluation, there is minimal attention or interest in isolating the underlying treatment effect of interest.

Publication Date:

Journal of Clinical Epidemiology

Evidence of unexplained discrepancies between planned and conducted statistical analyses: a review of randomised trials

Cro S, Forbes G, Johnson NA, Kahan BC

A review of published randomised trials, identifying a high rate of unexplained discrepancies between the planned and reported statistical methods used to analyse the primary outcome; therefore a need for improved reporting and transparency around statistical methods.

Publication Date:

BMC Medicine

Sensitivity analysis for clinical trials with missing continuous outcome data using controlled multiple imputation: A practical guide. Statistics in Medicine, 2020

Cro S, Morris TP, Kenward MG, Carpenter JR

This tutorial in biostatistics provides an accessible overview of controlled multiple imputation procedures, and a practical guide to their use for missing data sensitivity analysis of a continuous outcome in clinical trials. Worked examples and Stata code are presented.

Publication Date:

Statistics in Medicine

An evaluation of inverse probability weighting using the propensity score for baseline covariate adjustment in smaller population randomised controlled trials with a continuous outcome. BMC Medical Research Methodology, 2020

Raad H, Cornelius V, Chan S, Williamson E, Cro S

This article explores the use of IPTW for baseline covariate adjustment in small sample randomised trials and subsequently provides a caution on the use of IPTW without small sample modifications to the standard error calculation.

Publication Date:

BMC Medical Research Methodology

A randomised placebo controlled trial of anakinra for treating pustular psoriasis: statistical analysis plan for stage two of the APRICOT trial. Trials 2020

Cro, S., Patel, P., Barker, J, Burden D, Griffiths, Lachmann, H, Reynolds, N, Warron, R, Capon, F, Cornelius, V.

This paper reports the statistical analysis plan for the second stage for the APRICOT trial after the first stage adaptation has taken place.

Publication Date:

Trials Journal