Elizabeth G. Ryan

• Doctor of Philosophy
• Monash University (Australia)

The use of Bayesian adaptive designs for randomised controlled trials has been hindered by the lack of software readily available to statisticians. We have developed a new software package (Bayesian Adaptive Trials Simulator Software - BATSS for the statistical software R, which provides a flexible structure for the fast simulation of Bayesian adap...

Introduction Inequitable access to health care based on demographic factors such as ethnicity, socioeconomic status and geographical location has been consistently found in children with chronic kidney disease (CKD). However, little is known about the perspectives of caregivers on accessing health care. We described caregivers’ perspectives on acce...

Randomized controlled trials can be used to generate evidence on the efficacy and safety of new treatments in eating disorders research. Many of the trials previously conducted in this area have been deemed to be of low quality, in part due to a number of practical constraints. This article provides an overview of established and more innovative cl...

Background & significance: Hypogammaglobulinemia is common in patients with chronic lymphocytic leukemia (CLL), non-Hodgkin lymphoma (NHL) and multiple myeloma (MM), and associated with an increased risk of serious infection. Immunoglobulin (Ig) replacement therapy (IgRT) is widely used to reduce this risk, but national guidelines and clinical prac...

Background Kidney transplants from small pediatric donors are considered marginal and often transplanted as dual grafts. This study aimed to compare long-term outcomes between recipients of single kidney transplants (SKTs) and dual en bloc kidney transplants (EBKTs) from small pediatric donors. Methods Data were obtained from the Australia and New...

Background Data informing energy needs of people with spinal cord injury (SCI) and pressure injuries are scarce, the impact of surgical repair unknown, and the role of body composition in healing unexplored. The study aims were to investigate resting energy expenditure (REE) over the course of pressure injury surgical repair, compare with available...

Background: The optimal general anesthetic (GA) technique for stroke patients undergoing endovascular thrombectomy (ET) is unclear. We compared favorable outcomes and mortality in patients receiving propofol or volatile GA during ET and assessed associations between mean arterial pressure (MAP) and outcome. Methods: Ninety-three patients with an...

Introduction: The WHO estimates the incidence of iron deficiency anaemia in Australia is 25%. However there is considerable variation during pregnancy and in regional areas. Objective: The aim of this investigation is to quantify the incidence of iron deficiency anaemia during pregnancy within Far North Queensland. Design: This is a single-cen...

Large randomised trials provide the most reliable evidence of effectiveness of new treatments in clinical practice. However, the time and resources required to complete such trials can be daunting. An overarching clinical trial platform focused on a single condition or type of surgery, aiming to compare several treatments, with an option to stop an...

Background Children with chronic kidney disease (CKD) require multidisciplinary care to meet their complex healthcare needs. Patient navigators are trained non-medical personnel who assist patients and caregivers to overcome barriers to accessing health services through care coordination. This trial aims to determine the effectiveness of a patient...

Background This update summarises key changes made to the protocol since the publication of the original protocol for the NAVKIDS² trial of patient navigators for children with chronic kidney disease (CKD) experiencing social disadvantage and provides the statistical analysis plan (SAP) which has not previously been published. Methods/design The o...

The use of Bayesian adaptive designs for clinical trials has increased in recent years, particularly during the COVID‐19 pandemic. Bayesian adaptive designs offer a flexible and efficient framework for conducting clinical trials and may provide results that are more useful and natural to interpret for clinicians, compared to traditional approaches....

Background: Maternal preference for warm water immersion (WWI) and waterbirth is increasing, but adoption into obstetric guidelines and clinical practice remains limited. Concerns regarding safety and a paucity of evidence have been cited as reasons for the limited adoption and uptake. Aim: The aim was to investigate maternal and neonatal outcom...

Background Although the effectiveness of screening tools for detecting depression in pregnancy has been investigated, there is limited evidence on the cost-effectiveness. This is vital in providing full information to decision makers. This study aimed to explore the cost-effectiveness of different screening tools to identify depression in early pre...

Background It is unclear how best to identify and treat women with mental disorders in pregnancy and the year after birth (i.e. the perinatal period). Objectives (1) To investigate how best to identify depression at antenatal booking [work package (WP) 1]. (2) To estimate the prevalence of mental disorders in early pregnancy (WP1). (3) To develop...

Background Experiencing traumatic life events is associated with an increased risk of common mental disorders (CMDs), but studies investigating this association within Indigenous populations are limited. Aims The aim of this study was to investigate associations between trauma and CMDs after controlling for other exposures. Method Trauma exposure...

Introduction: The aim of this work is to perform a systematic review and meta-analysis of anti-tumor necrosis factor (anti-TNF) and anti-interleukin-17 (anti-IL-17) trials for spondyloarthritis, psoriatic arthritis, and psoriasis comparing rates of inflammatory bowel disease (IBD) events compared to placebo. Methods: MEDLINE, EMBASE, and The Coc...

Objectives We aimed to estimate the rate of psychogenic nonepileptic seizures (PNES) among patients presenting to an emergency department with presumed seizures. We also wanted to identify factors that can assist health care professionals in determining whether these events are likely to be epileptic or nonepileptic. Methods We performed two retro...

Introduction Hemodialysis (HD) with medium cut‐off (MCO) dialyzers may expand molecular clearance, predominantly larger middle molecules (molecular weight 25–60 kDa). However, the impact of MCO dialyzers on long‐term clearance of various other components of the uremic milieu is unknown. The tRial Evaluating Mid cut‐Off Value membrane clearance of A...

Reproductive medicine is imbued with debates over the results of key trials. This has resulted in heterogeneity in clinical practice and a disconnect between researchers and the patient group they aim to treat. The criticisms of trials originate from the nature of reproductive health conditions and limitations imposed in designing trials to assess...

Background: Bayesian adaptive methods are increasingly being used to design clinical trials and offer several advantages over traditional approaches. Decisions at analysis points are usually based on the posterior distribution of the treatment effect. However, there is some confusion as to whether control of type I error is required for Bayesian d...

Objective: To estimate prevalence of lifetime and current eating disorders (ED) in a sample of pregnant women in South-East London and to describe their sociodemographic and clinical characteristics. Method: Secondary analysis of data from a cross-sectional survey. Using a stratified sampling design, 545 pregnant women were recruited. Diagnostic...

Background: Bayesian adaptive designs can be more efficient than traditional methods for multi-arm randomised controlled trials. The aim of this work was to demonstrate how Bayesian adaptive designs can be constructed for multi-arm phase III clinical trials and assess potential benefits that these designs offer. Methods: We constructed several alt...

Background: Phase III trials often require large sample sizes, leading to high costs and delays in clinical decision-making. Group sequential designs can improve trial efficiency by allowing for early stopping for efficacy and/or futility, and thus may decrease the sample size, trial duration and associated costs. Bayesian approaches may offer addi...

Background: There is a growing interest in the use of Bayesian adaptive designs in late-phase clinical trials. This includes the use of stopping rules based on Bayesian analyses in which the frequentist type I error rate is controlled as in frequentist group-sequential designs. Methods: This paper presents a practical comparison of Bayesian and...

Background Bayesian adaptive methods are increasingly being used to design clinical trials and offer a number of advantages over traditional approaches. Decisions at analysis points are usually based on the posterior distribution of the parameter of interest. However, there is some confusion amongst statisticians and trialists as to whether control...

Background: Bayesian adaptive methods are increasingly being used to design clinical trials and offer several advantages over traditional approaches. Decisions at analysis points are usually based on the posterior distribution of the treatment effect. However, there is some confusion as to whether control of type I error is required for Bayesian de...

Objective: The primary objective was to estimate the population prevalence of specific phobias (including pregnancy related specific phobias) and associated mental disorders. The secondary objective was to investigate the effectiveness of routinely collected screening tools (depression and anxiety screens, Whooley and GAD-2 respectively) in identi...

Background: Depression is a common antenatal mental disorder associated with significant maternal morbidity and adverse fetal outcomes. However, there is a lack of research on the effectiveness or cost-effectiveness of psychological interventions for antenatal depression. Methods: A parallel-group, exploratory randomised controlled trial across...

Objective: There is limited evidence on the prevalence and odds of antenatal common mental disorders (CMDs) among migrant women and the effect on risk of intersecting variables such as immigration status and ethnicity. This study aimed to estimate the prevalence and odds of antenatal CMDs among migrant women compared to UK-born women in an inner-Lo...

Background: Bayesian adaptive designs can improve the efficiency of trials, and lead to trials that can produce high quality evidence more quickly, with fewer patients and lower costs than traditional methods. The aim of this work was to determine how Bayesian adaptive designs can be constructed for phase III clinical trials in critical care, and...

Introduction Research into what constitutes the best and most effective care for women with an acute severe postpartum mental disorder is lacking. The effectiveness and cost-effectiveness of psychiatric mother and baby units (MBUs) has not been investigated systematically and there has been no direct comparison of the outcomes of mothers and infant...

Objective: The traditional approach of null hypothesis testing dominates the design and analysis of randomised controlled trials. This study aimed to demonstrate how a simple Bayesian analysis could have been used to analyse the Optimisation of Perioperative Cardiovascular Management to Improve Surgical Outcome (OPTIMISE) trial to obtain more clini...

Background Young women aged 16–24 are at high risk of common mental disorders (CMDs), but the risk during pregnancy is unclear. Aims To compare the population prevalence of CMDs in pregnant women aged 16–24 with pregnant women ≥25 years in a representative cohort, hypothesising that younger women are at higher risk of CMDs (depression, anxiety dis...

Background People recovering from heroin addiction need better treatments than are currently offered. The chronic relapsing nature of drug dependence means that helping a patient to achieve abstinence is often difficult. Naltrexone blocks the effects of ingested heroin; however, evidence is conflicting regarding the best delivery method. Objective...

Purpose A systematic review and meta-analysis was conducted to answer the question ‘In adults with respiratory failure requiring invasive ventilation for more than 24 h, does a weaning strategy with early extubation to non-invasive ventilation (NIV) compared to invasive ventilation weaning reduce all-cause hospital mortality?’ Methods We included...

Objective To estimate the population prevalence of anxiety disorders during pregnancy and investigate the diagnostic accuracy of the two-item Generalised Anxiety Disorder scale (GAD-2) for a) GAD and b) any anxiety disorder. Design Cross-sectional survey using a stratified sampling design. Sampling weights were used in the analysis to adjust for t...

Background Adolescent depression is common and impairing. There is an urgent need to develop early interventions to prevent depression becoming entrenched. However, current psychological interventions are difficult to access and show limited evidence of effectiveness. Schools offer a promising setting to enhance access to interventions, including r...

Background There is limited evidence on the prevalence and identification of antenatal mental disorders. Aims To investigate the prevalence of mental disorders in early pregnancy and the diagnostic accuracy of depression-screening (Whooley) questions compared with the Edinburgh Postnatal Depression Scale (EPDS), against the Structured Clinical Int...

Objective: Symptoms of chronic fatigue syndrome (CFS) can be perpetuated by cognitive and behavioural responses to the illness. We aimed to determine the factor structure, reliability and validity of the 40-item Cognitive Behavioural Responses Questionnaire (CBRQ) using data gathered from CFS patients. We also propose a short version CBRQ for grea...

Correlation and regression assess the association between 2 or more variables. This article reviews the core knowledge needed to understand these analyses, moving from visual analysis in scatter plots through correlation, simple and multiple linear regression, and logistic regression. Correlation estimates the strength and direction of a relationsh...

Big Datasets are endemic, but are often notoriously difficult to analyse because of their size, heterogeneity and quality. The purpose of this paper is to open a discourse on the potential for modern decision theoretic optimal experimental design methods, which by their very nature have traditionally been applied prospectively, to improve the analy...

Background Delayed graft function (DGF) is traditionally defined as the requirement for dialysis during the first week after transplantation. DGF is a common complication of renal transplantation, and it negatively affects short- and long-term graft outcomes. Ischaemia reperfusion injury (IRI) is a prime contributor to the development of DGF. It is...

Prophylactic ureteric stenting in renal transplantation reduces major urological complications (MUCs). There is however morbidity related to the indwelling duration of a stent, we aimed to determine the optimal duration for stents in this clinical setting. Patients (aged 2-75 years) from 6 UK hospitals undergoing renal transplantation were recruite...

Due to the scale and complexity of data sets currently being collected in areas such as health, transportation, environmental science, engineering, information technology, business and finance, modern quantitative analysts are seeking improved and appropriate computational and statistical methods to explore, model and draw inferences from big data....

Background: Tracheostomy has traditionally been used as a means of facilitated mechanical ventilation in patients requiring respiratory management following cardiac surgery. However in the clinical setting, the advantages of tracheostomy has been questioned by concerns surrounding evidence of its association with increased risk of deep sternal wou...

Background Depression is a common antenatal mental disorder and is associated with an increased risk of adverse effects on the fetus and significant morbidity for the mother; if untreated it can also continue into the post-natal period and affect mother-infant interactions. There has been little research evaluating the effectiveness or cost-effecti...

Background Increasing evidence suggests that postnatal paternal depression is associated with adverse emotional, behavioural and cognitive outcomes in children. Despite this, few studies have determined the prevalence of fathers’ depressive symptoms during the first few years of their children’s lives and explored what factors are related to these...

Objective: This study reports follow-up data from a multicenter randomized controlled trial (n = 142) comparing the Maudsley Model of Anorexia Nervosa Treatment for Adults (MANTRA) with Specialist Supportive Clinical Management (SSCM) in outpatients with broadly defined anorexia nervosa (AN). At 12 months postrandomization, all patients had statis...

Bayesian inference has commonly been performed on nonlinear mixed effects models. However, there is a lack of research into performing Bayesian optimal design for nonlinear mixed effects models, especially those that require searches to be performed over several design variables. This is likely due to the fact that it is much more computationally i...

Bayesian experimental design is a fast growing area of research with many real-world applications. As computational power has increased over the years, so has the development of simulation-based design methods, which involve a number of algorithms, such as Markov chain Monte Carlo, sequential Monte Carlo and approximate Bayes methods, facilitating...

Excessive bleeding is a risk associated with cardiac surgery. Treatment invariably requires transfusion of blood products; however, the transfusion itself may contribute to postoperative sequelae. Our objective was to analyse a quality initiative designed to provide an evidenced-based approach to bleeding management. A retrospective analysis compar...

Utility functions in Bayesian experimental design are usually based on the posterior distribution. When the posterior is found by simulation, it must be sampled from for each future dataset drawn from the prior predictive distribution. Many thousands of posterior distributions are often required. A popular technique in the Bayesian experimental des...

The use of Bayesian methodologies for solving optimal experimental design problems has increased. Many of these methods have been found to be computationally intensive for design problems that require a large number of design points. A simulation-based approach that can be used to solve optimal design problems in which one is interested in finding...