Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Liz Cook is active.

Publication


Featured researches published by Liz Cook.


PLOS ONE | 2016

The completeness of intervention descriptions in randomised trials of supervised exercise training in peripheral arterial disease

Garry A. Tew; Sally Brabyn; Liz Cook; Emily Peckham

Research supports the use of supervised exercise training as a primary therapy for improving the functional status of people with peripheral arterial disease (PAD). Several reviews have focused on reporting the outcomes of exercise interventions, but none have critically examined the quality of intervention reporting. Adequate reporting of the exercise protocols used in randomised controlled trials (RCTs) is central to interpreting study findings and translating effective interventions into practice. The purpose of this review was to evaluate the completeness of intervention descriptions in RCTs of supervised exercise training in people with PAD. A systematic search strategy was used to identify relevant trials published until June 2015. Intervention description completeness in the main trial publication was assessed using the Template for Intervention Description and Replication checklist. Missing intervention details were then sought from additional published material and by emailing authors. Fifty-eight trials were included, reporting on 76 interventions. Within publications, none of the interventions were sufficiently described for all of the items required for replication; this increased to 24 (32%) after contacting authors. Although programme duration, and session frequency and duration were well-reported in publications, complete descriptions of the equipment used, intervention provider, and number of participants per session were missing for three quarters or more of interventions (missing for 75%, 93% and 80% of interventions, respectively). Furthermore, 20%, 24% and 26% of interventions were not sufficiently described for the mode of exercise, intensity of exercise, and tailoring/progression, respectively. Information on intervention adherence/fidelity was also frequently missing: attendance rates were adequately described for 29 (38%) interventions, whereas sufficient detail about the intensity of exercise performed was presented for only 8 (11%) interventions. Important intervention details are commonly missing for supervised exercise programmes in the PAD trial literature. This has implications for the interpretation of outcome data, the investigation of dose-response effects, and the replication of protocols in future studies and clinical practice. Researchers should be mindful of intervention reporting guidelines when attempting to publish information about supervised exercise programmes, regardless of the population being studied.


Contemporary Clinical Trials | 2015

The use of unequal randomisation in clinical trials — An update

Emily Peckham; Sally Brabyn; Liz Cook; Thomas Devlin; Jo C Dumville; David Torgerson

OBJECTIVE To update a 2005 review of the reasons researchers have given for the use of unequal randomisation in randomised controlled trials (RCTs). MAIN MEASURES Intervention being tested; type of study; number of participants; randomisation ratio; sample size calculation and reason given for using unequal randomisation. METHODS Review of trials using unequal randomisation. DATABASES AND SOURCES Cochrane library, Medline and CINAHL. RESULTS A total of 86 trials were identified. Of these 82 trials (95%) recruited patients in favour of the experimental group. Various reasons for the use of unequal randomisation were given including: gaining treatment experience; identification of adverse events; ethical; logistic and enhancing recruitment. No trial reported explicitly used it for cost-effectiveness. Most of the papers (i.e. 47, 55%) did not state why they had used unequal randomisation and only 38 trials (44%) appeared to have taken the unequal randomisation into account in their sample size calculation. CONCLUSION Most studies did not mention the rationale for unequal allocation, and a significant proportion did not appear to account for it in the sample size calculations. Unlike the previous review economic considerations were not stated as a rationale for its use. A number of trials used it to enhance recruitment, although this has not been tested.


Bone and Joint Research | 2014

Clinical trial networks in orthopaedic surgery

Amar Rangan; Laura Jefferson; Paul Baker; Liz Cook

The aim of this study was to review the role of clinical trial networks in orthopaedic surgery. A total of two electronic databases (MEDLINE and EMBASE) were searched from inception to September 2013 with no language restrictions. Articles related to randomised controlled trials (RCTs), research networks and orthopaedic research, were identified and reviewed. The usefulness of trainee-led research collaborations is reported and our knowledge of current clinical trial infrastructure further supplements the review. Searching yielded 818 titles and abstracts, of which 12 were suitable for this review. Results are summarised and presented narratively under the following headings: 1) identifying clinically relevant research questions; 2) education and training; 3) conduct of multicentre RCTs and 4) dissemination and adoption of trial results. This review confirms growing international awareness of the important role research networks play in supporting trials in orthopaedic surgery. Multidisciplinary collaboration and adequate investment in trial infrastructure are crucial for successful delivery of RCTs. Cite this article: Bone Joint Res 2014;3:169–74.


BMJ Open | 2016

Social Stories in mainstream schools for children with autism spectrum disorder: a feasibility randomised controlled trial

David Marshall; Barry Wright; Victoria Allgar; Joy Adamson; Christine Williams; Hannah Ainsworth; Liz Cook; Danielle Varley; Lisa Hackney; Paul Dempster; Shehzad Ali; Dominic Trépel; Danielle Collingridge Moore; Elizabeth Littlewood; Dean McMillan

Objectives To assess the feasibility of recruitment, retention, outcome measures and intervention training/delivery among teachers, parents and children. To calculate a sample size estimation for full trial. Design A single-centre, unblinded, cluster feasibility randomised controlled trial examining Social Stories delivered within a school environment compared with an attentional control. Setting 37 primary schools in York, UK. Participants 50 participants were recruited and a cluster randomisation approach by school was examined. Participants were randomised into the treatment group (n=23) or a waiting list control group (n=27). Outcome measures Acceptability and feasibility of the trial, intervention and of measurements required to assess outcomes in a definitive trial. Results An assessment of the questionnaire completion rates indicated teachers would be most appropriate to complete the primary outcome measure. 2 outcome measures: the Social Responsiveness Scale (SRS)-2 and a goal-based measure showed both the highest levels of completion rates (above 80%) at the primary follow-up point (6 weeks postintervention) and captured relevant social and behaviour outcomes. Power calculations were based on these 2 outcome measures leading to a total proposed sample size of 180 participant groups. Conclusions Results suggest that a future trial would be feasible to conduct and could inform the policy and practice of using Social Stories in mainstream schools. Trial registration number ISRCTN96286707; Results.


Trials | 2015

Aspirin for Venous Ulcers: Randomised Trial (AVURT): study protocol for a randomised controlled trial

Helen Tilbrook; Rachael Forsythe; Debbie Rolfe; Laura Clark; Martin Bland; Hannah Buckley; Ian Chetter; Liz Cook; Jo C Dumville; Rhian Gabe; Keith Gordon Harding; Alison Layton; Ellie Lindsay; Catriona McDaid; Christine Moffatt; Ceri Phillips; Gerard Stansby; Peter Vowden; Laurie Williams; David Torgerson; R. J. Hinchliffe

BackgroundVenous leg ulcers (VLUs) are the commonest cause of leg ulceration, affecting 1 in 100 adults. There is a significant health burden associated with VLUs – it is estimated that the cost of treatment for 1 ulcer is up to £1300 per year in the NHS. The mainstay of treatment is with graduated compression bandaging; however, treatment is often prolonged and up to one quarter of venous leg ulcers do not heal despite standard care. Two previous trials have suggested that low-dose aspirin, as an adjunct to standard care, may hasten healing, but these trials were small and of poor quality. Aspirin is an inexpensive, widely used medication but its safety and efficacy in the treatment of VLUs remains to be established.Methods/DesignAVURT is a phase II randomised double blind, parallel-group, placebo-controlled efficacy trial. The primary objective is to examine whether aspirin, in addition to standard care, is effective in patients with chronic VLUs (i.e. over 6 weeks in duration or a history of VLU). Secondary objectives include feasibility and safety of aspirin in this population. A target of 100 participants, identified from community leg ulcer clinics and hospital clinics, will be randomised to receive either 300 mg of aspirin once daily or placebo. All participants will receive standard care with compression therapy. The primary outcome will be time to healing of the reference ulcer. Follow-up will occur for a maximum of 27 weeks. The primary analysis will use a Cox proportional hazards model to compare time to healing using the principles of intention-to-treat. Secondary outcomes will include ulcer size, pain evaluation, compliance and adverse events.DiscussionThe AVURT trial will investigate the efficacy and safety of aspirin as a treatment for VLU and will inform on the feasibility of proceeding to a larger phase III study. This study will address the paucity of information currently available regarding aspirin therapy to treat VLU.Trial registrationThe study is registered on a public database with clinicaltrials.gov (NCT02333123; registered on 5 November 2014).


BMJ Open | 2014

Autism Spectrum Social Stories In Schools Trial (ASSSIST): study protocol for a feasibility randomised controlled trial analysing clinical and cost-effectiveness of Social Stories in mainstream schools

Barry Wright; David Marshall; Danielle Collingridge Moore; Hannah Ainsworth; Lisa Hackney; Joy Adamson; Shehzad Ali; Victoria Allgar; Liz Cook; Lisa Dyson; Elizabeth Littlewood; Rebecca Hargate; Anne McLaren; Dean McMillan; Dominic Trépel; Jo Whitehead; Christopher M. Williams

Introduction Current evidence suggests that Social Stories can be effective in tackling problem behaviours exhibited by children with autism spectrum disorder. Exploring the meaning of behaviour from a childs perspective allows stories to provide social information that is tailored to their needs. Case reports in children with autism have suggested that these stories can lead to a number of benefits including improvements in social interactions and choice making in educational settings. Methods and analysis The feasibility of clinical and cost-effectiveness of a Social Stories toolkit will be assessed using a randomised control framework. Participants (n=50) will be randomised to either the Social Stories intervention or a comparator group where they will be read standard stories for an equivalent amount of time. Statistics will be calculated for recruitment rates, follow-up rates and attrition. Economic analysis will determine appropriate measures of generic health and resource use categories for cost-effectiveness analysis. Qualitative analysis will ascertain information on perceptions about the feasibility and acceptability of the intervention. Ethics and dissemination National Health Service Ethics Approval (NHS; ref 11/YH/0340) for the trial protocol has been obtained along with NHS Research and Development permission from Leeds and York Partnership NHS Foundation Trust. All adverse events will be closely monitored, documented and reported to the study Data Monitoring Ethics Committee. At least one article in a peer reviewed journal will be published and research findings presented at relevant conferences. Trial registration number ISRCTN96286707.


Journal of Evidence-based Medicine | 2016

'Away Days' in multi-centre randomised controlled trials: a questionnaire survey of their use and a case study on the effect of one Away Day on patient recruitment.

Laura Jefferson; Liz Cook; Ada Keding; Stephen Brealey; Helen Handoll; Amar Rangan

“Away Days” (trial promotion and training events for trial site personnel) are a well‐established method used by trialists to encourage engagement of research sites in the recruitment of patients to multicenter randomized controlled trials (RCTs). We explored the use of Away Days in multicenter RCTs and analyzed the effect on patient recruitment in a case study.


Gait & Posture | 2019

Three-curve rocker-soled shoes and gait adaptations to intermittent claudication pain: A randomised crossover trial

Alastair R. Jordan; Garry A. Tew; Stephen W Hutchins; Ahmed Shalan; Liz Cook; Andrew J. Thompson

BACKGROUND Intermittent claudication (IC) is a symptom of peripheral arterial disease where a cramp-like leg pain is exhibited during walking, which affects gait and limits walking distance. Specifically-designed rocker-soled shoes were purported to mechanically unload the calf musculature and increase walking distances until IC pain. RESEARCH QUESTIONS Do three-curve rocker-soled shoes increase walking distance and what are the biomechanical differences during pain-free walking and IC pain-induced walking, when compared with control shoes? METHODS Following NHS ethical approval, 31 individuals with claudication (age 69 ± 10 years, stature 1.7 ± 0.9 m, mass 83.2 ± 16.2 kg, ankle-brachial pressure index 0.55 ± 0.14) were randomised in this cross-over trial. Gait parameters whilst walking with rocker-soled shoes were compared with control shoes at three intervals of pain-free walking, at onset of IC pain (initial claudication distance) and when IC intensifies and prevents them walking any further (absolute claudication distance). Two-way repeated measures ANOVA were performed on gait variables. RESULTS When compared with control shoes, rocker-soled shoes reduced ankle power generation (mean 2.1 vs 1.6 W/kg, respectively; p = 0.006) and altered sagittal kinematics of the hip, knee and ankle. However, this did not translate to a significant increase in initial (138 m vs 146 m, respectively) or absolute (373 m vs 406 m, respectively) claudication distances. In response to IC pain, similar adaptations in temporal-spatial parameters and the sagittal kinematics were observed between the shoe types. SIGNIFICANCE The three-curved rocker shoes, in their current design, do not augment gait sufficiently to enhance walking distance, when compared with control shoes, and therefore cannot be recommended for the intermittent claudication population. Clinical Reg No. (ClinicalTrials.gov): NCT02505503.


Health Technology Assessment | 2018

AVURT: aspirin versus placebo for the treatment of venous leg ulcers – a Phase II pilot randomised controlled trial

Helen Tilbrook; Laura Clark; Liz Cook; Martin Bland; Hannah Buckley; Ian Chetter; Jo C Dumville; Chris Fenner; Rachael Forsythe; Rhian Gabe; Keith Gordon Harding; Alison Layton; Ellie Lindsay; Catriona McDaid; Christine Moffatt; Debbie Rolfe; Illary Sbizzera; Gerard Stansby; David Torgerson; Peter Vowden; Laurie Williams; Robert Hinchliffe

BACKGROUND Venous leg ulcers (VLUs) are the most common cause of leg ulceration, affecting 1 in 100 adults. VLUs may take many months to heal (25% fail to heal). Estimated prevalence is between 1% and 3% of the elderly population. Compression is the mainstay of treatment and few additional therapies exist to improve healing. Two previous trials have indicated that low-dose aspirin, as an adjunct to standard care, may improve healing time, but these trials were insufficiently robust. Aspirin is an inexpensive, widely used medication but its safety and efficacy in the treatment of VLUs remains to be established. OBJECTIVES Primary objective - to assess the effects of 300 mg of aspirin (daily) versus placebo on the time to healing of the reference VLU. Secondary objectives - to assess the feasibility of leading into a larger pragmatic Phase III trial and the safety of aspirin in this population. DESIGN A multicentred, pilot, Phase II randomised double-blind, parallel-group, placebo-controlled efficacy trial. SETTING Community leg ulcer clinics or services, hospital outpatient clinics, leg ulcer clinics, tissue viability clinics and wound clinics in England, Wales and Scotland. PARTICIPANTS Patients aged ≥ 18 years with a chronic VLU (i.e. the VLU is > 6 weeks in duration or the patient has a history of VLU) and who are not regularly taking aspirin. INTERVENTIONS 300 mg of daily oral aspirin versus placebo. All patients were offered care in accordance with Scottish Intercollegiate Guidelines Network (SIGN) guidance with multicomponent compression therapy aiming to deliver 40 mmHg at the ankle when possible. RANDOMISATION Participants were allocated in a 1 : 1 (aspirin : placebo) ratio by the Research Pharmacy, St Georges University Hospitals NHS Foundation Trust, using a randomisation schedule generated in advance by the investigational medicinal product manufacturer. Randomisation was stratified according to ulcer size (≤ 5cm2 or > 5cm2). MAIN OUTCOME MEASURE The primary outcome was time to healing of the largest eligible ulcer (reference ulcer). FEASIBILITY RESULTS – RECRUITMENT 27 patients were recruited from eight sites over a period of 8 months. The target of 100 patients was not achieved and two sites did not recruit. Barriers to recruitment included a short recruitment window and a large proportion of participants failing to meet the eligibility criteria. RESULTS The average age of the 27 randomised participants (placebo, n = 13; aspirin, n = 14) was 62 years (standard deviation 13 years), and two-thirds were male (n = 18). Participants had their reference ulcer for a median of 15 months, and the median size of ulcer was 17.1 cm2. There was no evidence of a difference in time to healing of the reference ulcer between groups in an adjusted analysis for log-ulcer area and duration (hazard ratio 0.58, 95% confidence interval 0.18 to 1.85; p = 0.357). One expected, related serious adverse event was recorded for a participant in the aspirin group. LIMITATIONS The trial under-recruited because many patients did not meet the eligibility criteria. CONCLUSIONS There was no evidence that aspirin was efficacious in hastening the healing of chronic VLUs. It can be concluded that a larger Phase III (effectiveness) trial would not be feasible. TRIAL REGISTRATION Clinical Trials.gov NCT02333123; European Clinical Trials Database (EudraCT) 2014-003979-39. FUNDING This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 22, No. 55. See the NIHR Journals Library website for further project information.


JRSM open | 2016

No difference found in time to publication by statistical significance of trial results: a methodological review.

Laura Jefferson; Caroline Fairhurst; E Cooper; Catherine Hewitt; T Torgerson; Liz Cook; Puvan Tharmanathan; Sarah Cockayne; David Torgerson

Objective Time-lag from study completion to publication is a potential source of publication bias in randomised controlled trials. This study sought to update the evidence base by identifying the effect of the statistical significance of research findings on time to publication of trial results. Design Literature searches were carried out in four general medical journals from June 2013 to June 2014 inclusive (BMJ, JAMA, the Lancet and the New England Journal of Medicine). Setting Methodological review of four general medical journals. Participants Original research articles presenting the primary analyses from phase 2, 3 and 4 parallel-group randomised controlled trials were included. Main outcome measures Time from trial completion to publication. Results The median time from trial completion to publication was 431 days (n = 208, interquartile range 278–618). A multivariable adjusted Cox model found no statistically significant difference in time to publication for trials reporting positive or negative results (hazard ratio: 0.86, 95% CI 0.64 to 1.16, p = 0.32). Conclusion In contrast to previous studies, this review did not demonstrate the presence of time-lag bias in time to publication. This may be a result of these articles being published in four high-impact general medical journals that may be more inclined to publish rapidly, whatever the findings. Further research is needed to explore the presence of time-lag bias in lower quality studies and lower impact journals.

Collaboration


Dive into the Liz Cook's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Amar Rangan

James Cook University Hospital

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Jo C Dumville

Manchester Academic Health Science Centre

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge