24 hour consultant obstetrician presence on the labour ward and intrapartum outcomes in a large unit in England: A time series analysis.

Objectives: To explore the effect of introducing 24/7 resident labour ward consultant presence on neonatal and maternal outcomes in a large obstetric unit in England.

Design: Retrospective time sequence analysis of routinely collected data.

Setting: Obstetric unit of large teaching hospital in England.

Methodological issues in economic evaluations of emergency transport systems in low-income and middle-income countries.

A recent systematic review identified few papers on the economic evaluation of systems for emergency transport of acutely ill or injured patients. In addition, we found no articles dealing with the methodological challenges posed by such studies in low-income or middle-income countries. We therefore carried out an analysis of issues that are of particular salience to this important topic.

Design and analysis of three-arm parallel cluster randomized trials with small numbers of clusters.

In this article, we review and evaluate a number of methods used in the design and analysis of small three-arm parallel cluster randomized trials. We conduct a simulation-based study to evaluate restricted randomization methods including covariate-constrained randomization and a novel method for matched-group cluster randomization. We also evaluate the appropriate modelling of the data and small sample inferential methods for a variety of treatment effects relevant to three-arm trials.

The impact of varying cluster size in cross-sectional stepped-wedge cluster randomised trials.

Background: Cluster randomised trials with unequal sized clusters often have lower precision than with clusters of equal size. To allow for this, sample sizes are inflated by a modified version of the design effect for clustering. These inflation factors are valid under the assumption that randomisation is stratified by cluster size.

Reporting of stepped wedge cluster randomised trials: extension of the CONSORT 2010 statement with explanation and elaboration.

This report presents the Consolidated Standards of Reporting Trials (CONSORT) extension for the stepped wedge cluster randomised trial (SW-CRT). The SW-CRT involves randomisation of clusters to different sequences that dictate the order (or timing) at which each cluster will switch to the intervention condition. The statement was developed to allow for the unique characteristics of this increasingly used study design.

Sicker patients account for the weekend mortality effect among adult emergency admissions to a large hospital trust.

Objective: To determine whether the higher weekend admission mortality risk is attributable to increased severity of illness.

Design: Retrospective analysis of 4 years weekend and weekday adult emergency admissions to a university teaching hospital in England.

Outcome Measures: 30-day postadmission weekend:weekday mortality ratios adjusted for severity of illness (baseline National Early Warning Score (NEWS)), routes of admission to hospital, transfer to the intensive care unit (ICU) and demographics.

Relative efficiency of unequal cluster sizes in stepped wedge and other trial designs under longitudinal or cross-sectional sampling.

Background: A cluster trial with unequal cluster sizes often has lower precision than one with equal clusters, with a corresponding inflation of the design effect. For parallel group trials, adjustments to the design effect are available under sampling models with a single intracluster correlation. Design effects for equal clusters under more complex scenarios have appeared recently (including stepped wedge trials under cross-sectional or longitudinal sampling).

Improving outcomes after pediatric cardiac arrest - the ICU-Resuscitation Project: study protocol for a randomized controlled trial.

Background: Quality of cardiopulmonary resuscitation (CPR) is associated with survival, but recommended guidelines are often not met, and less than half the children with an in-hospital arrest will survive to discharge. A single-center before-and-after study demonstrated that outcomes may be improved with a novel training program in which all pediatric intensive care unit staff are encouraged to participate in frequent CPR refresher training and regular, structured resuscitation debriefings focused on patient-centric physiology.

Methods/design: This ongoing trial will assess whether a program of structured debriefings and point-of-care bedside practice that emphasizes physiologic resuscitation targets improves the rate of survival to hospital discharge with favorable neurologic outcome in children receiving CPR in the intensive care unit.

Impact of a commercial order entry system on prescribing errors amenable to computerised decision support in the hospital setting: a prospective pre-post study.

Background: In this UK study, we investigated the impact of computerised physician order entry (CPOE) and clinical decision support (CDS) implementation on the rate of 78 high-risk prescribing errors amenable to CDS.

Methods: We conducted a preintervention/postintervention study in three acute hospitals in England. A predefined list of prescribing errors was incorporated into an audit tool.

Protocol for the health economic evaluation of increasing the weekend specialist to patient ratio in hospitals in England.

Introduction: This protocol concerns the evaluation of increased specialist staffing at weekends in hospitals in England. Seven-day health services are a key policy for the UK government and other health systems trying to improve use of infrastructure and resources. A particular motivation for the 7-day policy has been the observed increase in the risk of death associated with weekend admission, which has been attributed to fewer hospital specialists being available at weekends.

Two-epoch cross-sectional case record review protocol comparing quality of care of hospital emergency admissions at weekends versus weekdays.

Introduction: The mortality associated with weekend admission to hospital (the 'weekend effect') has for many years been attributed to deficiencies in quality of hospital care, often assumed to be due to suboptimal senior medical staffing at weekends. This protocol describes a case note review to determine whether there are differences in care quality for emergency admissions (EAs) to hospital at weekends compared with weekdays, and whether the difference has reduced over time as health policies have changed to promote 7-day services.

Methods And Analysis: Cross-sectional two-epoch case record review of 20 acute hospital Trusts in England.

Intra-cluster and inter-period correlation coefficients for cross-sectional cluster randomised controlled trials for type-2 diabetes in UK primary care.

Background: Clustered randomised controlled trials (CRCTs) are increasingly common in primary care. Outcomes within the same cluster tend to be correlated with one another. In sample size calculations, estimates of the intra-cluster correlation coefficient (ICC) are needed to allow for this nonindependence.

Proceedings of the First International Conference on Stepped Wedge Trial Design : York, UK, 10 March 2016.

I1 Introduction Mona Kanaan, Noreen Dadirai Mdege, Ada Keding O1 The HiSTORIC trial: a hybrid before-and-after and stepped wedge design RA Parker, N Mills, A Shah, F Strachan, C Keerie, CJ Weir O2 Stepped wedge trials with non-uniform correlation structure Andrew Forbes, Karla Hemming O3 Challenges and solutions for the operationalisation of the ENHANCE study: a pilot stepped wedge trial within a general practice setting Sarah A Lawton, Emma Healey, Martyn Lewis, Elaine Nicholls, Clare Jinks, Valerie Tan, Andrew Finney, Christian D Mallen, on behalf of the ENHANCE Study Team O4 Early lessons from the implementation of a stepped wedge trial design investigating the effectiveness of a training intervention in busy health care settings: the Thistle study Erik Lenguerrand, Graeme MacLennan, John Norrie, Siladitya Bhattacharya, Tim Draycott, on behalf of the Thistle group O5 Sample size calculation for longitudinal cluster randomised trials: a unified framework for closed cohort and repeated cross-section designs Richard Hooper, Steven Teerenstra, Esther de Hoop, Sandra Eldridge O6 Restricted randomisation schemes for stepped-wedge studies with a cluster-level covariate Alan Girling, Monica Taljaard O7 A flexible modelling of the time trend for the analysis of stepped wedge trials: results of a simulation study Gian Luca Di Tanna, Antonio Gasparrini P1 Tackling acute kidney injury – a UK stepped wedge clinical trial of hospital-level quality improvement interventions Anna Casula, Fergus Caskey, Erik Lenguerrand, Shona Methven, Stephanie MacNeill, Margaret May, Nicholas Selby P2 Sample size considerations for quantifying secondary bacterial transmission in a stepped wedge trial of influenza vaccine Leon Danon, Hannah Christensen, Adam Finn, Margaret May P3 Sample size calculation for time-to-event data in stepped wedge cluster randomised trials Fumihito Takanashi, Ada Keding, Simon Crouch, Mona Kanaan P4 Sample size calculations for stepped-wedge cluster randomised trials with unequal cluster sizes Caroline A. Kristunas, Karen L. Smith, Laura J.

Reviewing deaths in British and US hospitals: a study of two scales for assessing preventability.

Background: Standardised mortality ratios do not provide accurate measures of preventable mortality. This has generated interest in using case notes to assess the preventable component of mortality. But, different methods of measurement have not been compared.

Weekend specialist intensity and admission mortality in acute hospital trusts in England: a cross-sectional study.

Background: Increased mortality rates associated with weekend hospital admission (the so-called weekend effect) have been attributed to suboptimum staffing levels of specialist consultants. However, evidence for a causal association is elusive, and the magnitude of the weekend specialist deficit remains unquantified. This uncertainty could hamper efforts by national health systems to introduce 7 day health services.

Researching Complex Interventions in Health: The State of the Art : Exeter, UK. 14-15 October 2015.

KEYNOTE PRESENTATIONS K1 Researching complex interventions: the need for robust approaches Peter Craig K2 Complex intervention studies: an important step in developing knowledge for practice Ingalill Rahm-Hallberg K3 Public and patient involvement in research: what, why and how? Nicky Britten K4 Mixed methods in health service research – where do we go from here? Gunilla Borglin SPEAKER PRESENTATIONS S1 Exploring complexity in systematic reviews of complex interventions Gabriele Meyer, Sascha Köpke, Jane Noyes, Jackie Chandler S2 Can complex health interventions be optimised before moving to a definitive RCT? Strategies and methods currently in use Sara Levati S3 A systematic approach to develop theory based implementation interventions Anne Sales S4 Pilot studies and feasibility studies for complex interventions: an introduction Lehana Thabane, Lora Giangregorio S5 What can be done to pilot complex interventions? Nancy Feeley, Sylvie Cossette S6 Using feasibility and pilot trials to test alternative methodologies and methodological procedures prior to full scale trials Rod Taylor S7 A mixed methods feasibility study in practice Jacqueline Hill, David A Richards, Willem Kuyken S8 Non-standard experimental designs and preference designs Louise von Essen S9 Evaluation gone wild: using natural experimental approaches to evaluate complex interventions Andrew Williams S10 The stepped wedge cluster randomised trial: an opportunity to increase the quality of evaluations of service delivery and public policy interventions Karla Hemming, Richard Lilford, Alan Girling, Monica Taljaard S11 Adaptive designs in confirmatory clinical trials: opportunities in investigating complex interventions Munyaradzi Dimairo S12 Processes, contexts and outcomes in complex interventions, and the implications for evaluation Mark Petticrew S13 Processes, contexts and outcomes in complex interventions, and the implications for evaluation Janis Baird, Graham Moore S14 Qualitative evaluation alongside RCTs: what to consider to get relevant and valuable results Willem Odendaal, Salla Atkins, Elizabeth Lutge, Natalie Leon, Simon Lewin S15 Using economic evaluations to understand the value of complex interventions: when maximising health status is not sufficient Katherine Payne S16 How to arrive at an implementation plan Theo van Achterberg S17 Modelling process and outcomes in complex interventions Walter Sermeus S18 Systems modelling for improving health care Martin Pitt, Thomas Monks

Systematic review finds major deficiencies in sample size methodology and reporting for stepped-wedge cluster randomised trials.

Background: Stepped-wedge cluster randomised trials (SW-CRT) are increasingly being used in health policy and services research, but unless they are conducted and reported to the highest methodological standards, they are unlikely to be useful to decision-makers. Sample size calculations for these designs require allowance for clustering, time effects and repeated measures.

Methods: We carried out a methodological review of SW-CRTs up to October 2014.