Re-analysis of data from cluster randomised trials to explore the impact of model choice on estimates of odds ratios: study protocol.

Background: There are numerous approaches available to analyse data from cluster randomised trials. These include cluster-level summary methods and individual-level methods accounting for clustering, such as generalised estimating equations and generalised linear mixed models. There has been much methodological work showing that estimates of treatment effects can vary depending on the choice of approach, particularly when estimating odds ratios, essentially because the different approaches target different estimands.

Performance of mixed effects models and generalized estimating equations for continuous outcomes in partially clustered trials including both independent and paired data.

Many clinical trials involve partially clustered data, where some observations belong to a cluster and others can be considered independent. For example, neonatal trials may include infants from single or multiple births. Sample size and analysis methods for these trials have received limited attention.

A simple and effective method for simulating nested exchangeable correlated binary data for longitudinal cluster randomised trials.

Background: Simulation is an important tool for assessing the performance of statistical methods for the analysis of data and for the planning of studies. While methods are available for the simulation of correlated binary random variables, all have significant practical limitations for simulating outcomes from longitudinal cluster randomised trial designs, such as the cluster randomised crossover and the stepped wedge trial designs. For these trial designs as the number of observations in each cluster increases these methods either become computationally infeasible or their range of allowable correlations rapidly shrinks to zero.

Unravelling the effect of anaesthesia provider sex on patient outcomes: statistical analyses for sound conclusions.

Unravelling the impact of the sex of the anaesthesia provider on the outcomes of patients requires careful statistical analysis and the validity of many assumptions. A recent study in the British Journal of Anaesthesia investigates the effect of anaesthesia provider sex on patient outcomes, using data from two academic healthcare networks in the USA. The authors show that female provider sex was associated with a lower risk of intraoperative complications.

Same-visit hepatitis C testing and treatment to accelerate cure among people who inject drugs (the QuickStart Study): a cluster randomised cross-over trial protocol.

Introduction: Despite universal access to government-funded direct-acting antivirals (DAAs) in 2016, the rate of hepatitis C treatment uptake in Australia has declined substantially. Most hepatitis C is related to injecting drug use; reducing the hepatitis C burden among people who inject drugs (PWID) is, therefore, paramount to reach hepatitis C elimination targets. Increasing DAA uptake by PWID is important for interrupting transmission and reducing incidence, as well as reducing morbidity and mortality and improving quality of life of PWID and meeting Australia's hepatitis C elimination targets.

SCANPatient: study protocol for a multi-centre, batched, stepped wedge, comparative effectiveness, randomised clinical trial of synoptic reporting of computerised tomography (CT) scans assessing cancers of the pancreas.

Background: Complete surgical removal of pancreatic ductal adenocarcinoma (PDAC) is central to all curative treatment approaches for this aggressive disease, yet this is only possible in patients technically amenable to resection. Hence, an accurate assessment of whether patients are suitable for surgery is of paramount importance. The SCANPatient trial aims to test whether implementing a structured synoptic radiological report results in increased institutional accuracy in defining surgical resectability of non-metastatic PDAC.

Neuromuscular Control and Resistance Training for People With Chronic Low Back Pain: A Randomized Controlled Trial.

To determine if adding lumbar neuromuscular control retraining exercises to a 12-week program of strengthening exercises had greater effect for improving disability than 12 weeks of strengthening exercises alone in people with chronic low back pain (LBP). Single-center, participant- and assessor-blinded, comparative effectiveness randomized controlled trial. Sixty-nine participants (31 females; 29 males; mean age: 46.

Practical and methodological challenges when conducting a cluster randomized trial: Examples and recommendations.

The use of cluster randomized trial design to answer research questions is increasing. This design and associated variants such as the cluster randomized crossover and stepped wedge are useful to assess complex interventions in a pragmatic way but when adopting such designs, one may face specific implementation challenges. This article summarizes common challenges faced when conducting cluster randomized trials, cluster randomized crossover trials, and stepped wedge trials, and provides recommendations.

What type of cluster randomized trial for which setting?

The cluster randomized trial allows a randomized evaluation when it is either not possible to randomize the individual or randomizing individuals would put the trial at high risk of contamination across treatment arms. There are many variations of the cluster randomized design, including the parallel design with or without baseline measures, the cluster randomized cross-over design, the stepped-wedge cluster randomized design, and more recently-developed variants such as the batched stepped-wedge design and the staircase design. Once it has been clearly established that there is a need for cluster randomization, one ever important question is which form the cluster design should take.

Telerehabilitation consultations with a physiotherapist for chronic knee pain versus in-person consultations in Australia: the PEAK non-inferiority randomised controlled trial.

Background: Telerehabilitation is perceived as less effective than in-person care for musculoskeletal problems. We aimed to determine if physiotherapy video conferencing consultations were non-inferior to in-person consultations for chronic knee pain.

Methods: In this non-inferiority randomised controlled trial, we recruited primary care physiotherapists from 27 Australian clinics.

Protocol and statistical analysis plan for the mega randomised registry trial research program comparing conservative versus liberal oxygenation targets in adults receiving unplanned invasive mechanical ventilation in the ICU (Mega-ROX).

The effect of conservative versus liberal oxygen therapy on 90-day in-hospital mortality in patients who require unplanned invasive mechanical ventilation in an intensive care unit (ICU) is uncertain and will be evaluated in the mega randomised registry trial research program (Mega-ROX). To summarise the protocol and statistical analysis plan for Mega-ROX. Mega-ROX is a 40 000-patient parallel-group, registry-embedded clinical trial in which adults who require unplanned invasive mechanical ventilation in an ICU will be randomly assigned to conservative or liberal oxygen therapy.

The staircase cluster randomised trial design: A pragmatic alternative to the stepped wedge.

This article introduces the 'staircase' design, derived from the zigzag pattern of steps along the diagonal of a stepped wedge design schematic where clusters switch from control to intervention conditions. Unlike a complete stepped wedge design where all participating clusters must collect and provide data for the entire trial duration, clusters in a staircase design are only required to be involved and collect data for a limited number of pre- and post-switch periods. This could alleviate some of the burden on participating clusters, encouraging involvement in the trial and reducing the likelihood of attrition.

Protocol and statistical analysis plan for the mega randomised registry trial comparing conservative vs. liberal oxygenation targets in adults with nonhypoxic ischaemic acute brain injuries and conditions in the intensive care unit (Mega-ROX Brains).

Background: The effect of conservative vs. liberal oxygen therapy on 90-day in-hospital mortality in adults who have nonhypoxic ischaemic encephalopathy acute brain injuries and conditions and are receiving invasive mechanical ventilation in the intensive care unit (ICU) is uncertain.

Objective: The objective of this study was to summarise the protocol and statistical analysis plan for the Mega-ROX Brains trial.

Protocol and statistical analysis plan for the mega randomised registry trial comparing conservative vs. liberal oxygenation targets in adults with sepsis in the intensive care unit (Mega-ROX Sepsis).

Background: The effect of conservative vs. liberal oxygen therapy on 90-day in-hospital mortality in adults with sepsis receiving unplanned invasive mechanical ventilation in the intensive care unit (ICU) is uncertain.

Objective: The objective of this study was to summarise the protocol and statistical analysis plan for the Mega-ROX Sepsis trial.

Methotrexate to treat hand osteoarthritis with synovitis (METHODS): an Australian, multisite, parallel-group, double-blind, randomised, placebo-controlled trial.

Background: Hand osteoarthritis is a disabling condition with few effective therapies. Hand osteoarthritis with synovitis is a common inflammatory phenotype associated with pain. We aimed to examine the efficacy and safety of methotrexate at 6 months in participants with hand osteoarthritis and synovitis.

Expanding community pharmacists' scope of practice in relation to contraceptive counselling and referral: a protocol for a pragmatic, stepped-wedge, cluster randomised trial (ALLIANCE).

Introduction: Improving access to effective contraception has the potential to reduce unintended pregnancy and abortion rates. Community pharmacists could play an expanded role in contraceptive counselling and referral to contraceptive prescribers particularly when women are already attending community pharmacy to obtain emergency contraceptive pills (ECPs) or to have medical abortion (MA) medicines dispensed. The ALLIANCE trial aims to compare the subsequent uptake of effective contraception (hormonal or intrauterine) in women seeking ECP or MA medicines, who receive the ALLIANCE community pharmacy-based intervention with those who do not receive the intervention.

Generalizing the information content for stepped wedge designs: A marginal modeling approach.

Stepped wedge trials are increasingly adopted because practical constraints necessitate staggered roll-out. While a complete design requires clusters to collect data in all periods, resource and patient-centered considerations may call for an incomplete stepped wedge design to minimize data collection burden. To study incomplete designs, we expand the metric of information content to discrete outcomes.

Does it decay? Obtaining decaying correlation parameter values from previously analysed cluster randomised trials.

A frequently applied assumption in the analysis of data from cluster randomised trials is that the outcomes from all participants within a cluster are equally correlated. That is, the intracluster correlation, which describes the degree of dependence between outcomes from participants in the same cluster, is the same for each pair of participants in a cluster. However, recent work has discussed the importance of allowing for this correlation to decay as the time between the measurement of participants in a cluster increases.

A protocol for the Heart Matters stepped wedge cluster randomised trial: The effectiveness of heart attack education in regions at highest-risk.

Aim: To describe the Heart Matters (HM) trial which aims to evaluate the effectiveness of a community heart attack education intervention in high-risk areas in Victoria, Australia. These local government areas (LGAs) have high rates of acute coronary syndrome (ACS), out-of-hospital cardiac arrest (OHCA), cardiovascular risk factors, and low rates of emergency medical service (EMS) use for ACS.

Methods: The trial follows a stepped-wedge cluster randomised design, with eight clusters (high-risk LGAs) randomly assigned to transition from control to intervention every four months.

Compliance-Adjusted Estimates of Aspirin Effects Among Older Persons in the ASPREE Randomized Trial.

The Aspirin in Reducing Events in the Elderly (ASPREE) Trial recruited 19,114 participants across Australia and the United States during 2010-2014. Participants were randomized to receive either 100 mg of aspirin daily or matching placebo, with disability-free survival as the primary outcome. During a median 4.

Predicting Death or Disability after Surgery in the Older Adult.

Background: Older patients are vulnerable to developing new or worsening disability after surgery. Despite this, patient or surgical characteristics predisposing to postoperative disability are poorly defined. The aim of the study was to develop and validate a model, subsequently transformed to point-score form, to predict 6-month death or disability in older patients after surgery.

The impact of iterative removal of low-information cluster-period cells from a stepped wedge design.

Background: Standard stepped wedge trials, where clusters switch from the control to the intervention condition in a staggered manner, can be costly and burdensome. Recent work has shown that the amount of information contributed by each cluster in each period differs, with some cluster-periods contributing a relatively small amount of information. We investigate the patterns of the information content of cluster-period cells upon iterative removal of low-information cells, assuming a model for continuous outcomes with constant cluster-period size, categorical time period effects, and exchangeable and discrete-time decay intracluster correlation structures.