Ian Sinha

Using the Delphi technique to determine which outcomes to measure in clinical trials: recommendations for the future based on a systematic review of existing studies.

Ian Sinha and colleagues advise that when using the Delphi process to develop core outcome sets for clinical trials, patients and clinicians be involved, researchers and facilitators avoid imposing their views on participants, and attrition of participants be minimized.

A systematic review of studies that aim to determine which outcomes to measure in clinical trials in children.

Background In clinical trials the selection of appropriate outcomes is crucial to the assessment of whether one intervention is better than another. Selection of inappropriate outcomes can compromise the utility of a trial. However, the process of selecting the most suitable outcomes to include can be complex. Our aim was to systematically review studies that address the process of selecting outcomes or outcome domains to measure in clinical trials in children. Methods and Findings We searched Cochrane databases (no date restrictions) in December 2006; and MEDLINE (1950 to 2006), CINAHL (1982 to 2006), and SCOPUS (1966 to 2006) in January 2007 for studies of the selection of outcomes for use in clinical trials in children. We also asked a group of experts in paediatric clinical research to refer us to any other relevant studies. From these articles we extracted data on the clinical condition of interest, description of the method used to select outcomes, the people involved in the selection process, the outcomes selected, and limitations of the method as defined by the authors. The literature search identified 8,889 potentially relevant abstracts. Of these, 70 were retrieved, and 25 were included in the review. These studies described the work of 13 collaborations representing various paediatric specialties including critical care, gastroenterology, haematology, psychiatry, neurology, respiratory paediatrics, rheumatology, neonatal medicine, and dentistry. Two groups utilised the Delphi technique, one used the nominal group technique, and one used both methods to reach a consensus about which outcomes should be measured in clinical trials. Other groups used semistructured discussion, and one group used a questionnaire-based survey. The collaborations involved clinical experts, research experts, and industry representatives. Three groups involved parents of children affected by the particular condition. Conclusions Very few studies address the appropriate choice of outcomes for clinical research with children, and in most paediatric specialties no research has been undertaken. Among the studies we did assess, very few involved parents or children in selecting outcomes that should be measured, and none directly involved children. Research should be undertaken to identify the best way to involve parents and children in assessing which outcomes should be measured in clinical trials.

Development of a core outcome set for clinical trials in childhood asthma: a survey of clinicians, parents, and young people

BackgroundIn clinical trials in childhood asthma, outcomes reflecting short-term disease activity are frequently measured, whilst functional status, quality of life (QoL), and long-term treatment effects are rarely assessed. There is also non-uniformity across studies in the selection and measurement of outcomes within these domains. The development of a core outcome set has the potential to reduce heterogeneity between trials, lead to research that is more likely to have measured relevant outcomes, and enhance the value of evidence synthesis by reducing the risk of outcome reporting bias and ensuring that all trials contribute usable information.MethodsPaediatricians and specialist nurses, identified through the British Paediatric Respiratory Society, completed a two-round Delphi survey. Separate cohorts of parents of children younger than 18 years, recruited in clinics, participated in each round. Young people with asthma, aged at least 13 years, participated in the first round. Outcomes were identified separately for preschool and school-aged children.We identified outcomes considered important in routine clinical assessment by clinicians and parents/young people. In round 1, 46 clinicians suggested outcomes they considered important when deciding whether to adjust a child’s asthma therapy regime, and 49 parents/young people were asked, using open questions, how they judged whether their child’s (for young people, their own) asthma therapy was appropriate. Two researchers independently classified responses into appropriate, corresponding outcomes.In round 2, 43 clinicians and 50 parents scored, from 0–4, the importance of each outcome suggested by at least 10 % of round 1 responders and selected the three most important.ResultsThe most important outcomes, when making shared decisions about regular therapies for school-aged and preschool children with asthma, were daytime and nocturnal symptoms, exacerbations, QoL, and mortality. Results from parents and clinicians were generally concordant, but parents placed more emphasis on long-term treatment effects.ConclusionsWe have developed a methodology to identify outcomes of most relevance to clinicians, parents, and young people when evaluating regularly administered therapies for asthma. Daytime and nocturnal symptoms, exacerbations, QoL, and mortality are particularly important outcomes that should be measured and reported in all clinical trials of regular therapies for children with asthma.

Standard 5: Selection, Measurement, and Reporting of Outcomes in Clinical Trials in Children

* Abbreviations: CONSORT — : Consolidated Standards of Reporting Trials OMERACT — : Outcome Measures in Rheumatology PROM — : patient-reported outcome measure People making choices in health care should use the findings of clinical trials (ideally, incorporated in systematic reviews) to inform their decisions. If these findings are to be useful and reliable, researchers must select appropriate outcomes, measure them in a scientifically robust manner, and report results thoroughly. There are difficulties, however, relating to the selection and measurement of outcomes in clinical trials, and special considerations are needed when these studies are conducted in children. This article provides guidance for researchers working on clinical trials in children. Although this article is focused on trials of effectiveness, which are similar to therapeutic confirmatory trials, certain sections may also relate to efficacy trials, pharmacokinetic trials, therapeutic exploratory trials, and trials conducted earlier in drug development. To be useful, clinical trials that evaluate potential benefits and harms of health care interventions must measure outcomes of relevance to practitioners and patients who make shared decisions about treatment options; regulatory authorities who consider applications for marketing authorizations for medicines; organizations who decide whether to provide funding for an intervention (eg, health care commissioners, insurance companies); and policy makers interested in the impact of an intervention. It can be difficult, however, to decide which outcomes to measure in clinical trials. One reason is that the impact of illnesses is very variable, and some, but not all, may be improved by an intervention. Various frameworks for considering the effects of illnesses have been suggested,1–4 and others are in development. It may not be immediately obvious which of these effects are of particular importance, and the key aspects of the effects of health care interventions might vary between trials. For example, domains such as short-term measures of disease activity, prevention of symptoms, functional status, longer-term consequences of the illness, overall well-being, and utilization of health care … Address correspondence to Rosalind L. Smyth, Department of Women’s and Children’s Health, Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom. E-mail: r.l.smyth{at}liv.ac.uk

Outcomes in Clinical Trials of Inhaled Corticosteroids for Children with Asthma Are Narrowly Focussed on Short Term Disease Activity

Background Little work has been done to determine which outcomes should be measured in randomised controlled trials (RCTs) in children with asthma. Drug regulatory authorities require that short term disease activity is measured, but other outcome domains are not mandatory for licensing and marketing purposes. We aimed to identify whether any domains were underrepresented in RCTs of regular therapies for children with asthma over a 20 year period, and to examine what consistency there was between RCTs in the outcomes used to assess the domains. Methodology/Principal Findings By searching the Cochrane Central Register of Controlled Trials in January 2008, we identified all parallel-group RCTs, published between January 1988 and December 2007, which assessed inhaled corticosteroids (ICS) as regular therapy for children with asthma. We evaluated how frequently RCTs measured the following pre-defined domains: disease activity; disease damage; functional status; quality of life; health resource utilisation; and adverse effects of therapy. Our initial search identified 1668 abstracts, of which 412 were retrieved in full. 159 RCTs, of which 115 involved only children and 44 involved children and adults, were included in the review. Disease activity was measured in 157 RCTs, adverse effects of ICS in 135, functional status in 25, quality of life in 21, and health resource utilisation in 17. No RCT measured long term disease damage, although two used FEV1 as a measure of ‘lung growth’. RCTs were inconsistent in the outcomes used to measure the domains. Conclusions Short term disease activity is the most frequently measured outcome domain in RCTs in children with asthma. Effects of regular therapies on functional status, quality of life, and long term consequences of asthma are infrequently assessed. A core set of outcomes, developed using consensus techniques, would standardise the measurement of appropriate outcomes in these RCTs. Involving patients would identify outcomes which are most relevant from their perspective.

CPAP and High-Flow Nasal Cannula Oxygen in Bronchiolitis

Severe respiratory failure develops in some infants with bronchiolitis because of a complex pathophysiologic process involving increased airways resistance, alveolar atelectasis, muscle fatigue, and hypoxemia due to mismatch between ventilation and perfusion. Nasal CPAP and high-flow nasal cannula (HFNC) oxygen may improve the work of breathing and oxygenation. Although the mechanisms behind these noninvasive modalities of respiratory support are not well understood, they may help infants by way of distending pressure and delivery of high concentrations of warmed and humidified oxygen. Observational studies of varying quality have suggested that CPAP and HFNC may confer direct physiologic benefits to infants with bronchiolitis and that their use has reduced the need for intubation. No trials to our knowledge, however, have compared CPAP with HFNC in bronchiolitis. Two randomized trials compared CPAP with oxygen delivered by low-flow nasal cannula or face mask and found some improvements in blood gas results and some physiologic parameters, but these trials were unable to demonstrate a reduction in the need for intubation. Two trials evaluated HFNC in bronchiolitis (one comparing it with headbox oxygen, the other with nebulized hypertonic saline), with the results not seeming to suggest important clinical or physiologic benefits. In this article, we review the pathophysiology of respiratory failure in bronchiolitis, discuss these trials in detail, and consider how future research studies may be designed to best evaluate CPAP and HFNC in bronchiolitis.

Salbutamol or aminophylline for acute severe asthma: how to choose which one, when and why?

Acute, severe exacerbations of asthma present a challenge due to the significant morbidity associated with this presentation. For exacerbations that are refractory to initial treatments with inhaled and oral therapies, there is still doubt about which intravenous therapies are most likely to be helpful. β-2 agonists and aminophylline have differing mechanisms of action that also affect their adverse effects profiles and these are considered. A review of the available randomised control trials suggests that a bolus of intravenous salbutamol may reduce symptoms and hasten recovery. Aminophylline infusions may improve lung function, and in some studies have been shown to improve symptoms, but the evidence is not clear cut. Decisions about which treatment to use should include risk management considerations such as ease of prescription, preparation and administration factors and availability of high-dependency beds.

Inhaled short-acting bronchodilators for managing emergency childhood asthma: an overview of reviews

International guidelines provide conflicting recommendations on how to use bronchodilators to manage childhood acute wheezing conditions in the emergency department (ED), and there is variation within and among countries in how these conditions are managed. This may be reflective of uncertainty about the evidence. This overview of systematic reviews (SRs) aimed to synthesize, appraise, and present all SR evidence on the efficacy and safety of inhaled short‐acting bronchodilators to treat asthma and wheeze exacerbations in children 0–18 years presenting to the ED. Searching, review selection, data extraction and analysis, and quality assessments were conducted using methods recommended by The Cochrane Collaboration. Thirteen SRs containing 56 relevant trials and 5526 patients were included. Results demonstrate the efficacy of short‐acting beta‐agonist (SABA) delivered by metered‐dose inhaler as first‐line therapy for younger and older children (hospital admission decreased by 44% in younger children, and ED length of stay decreased by 33 min in older children). Short‐acting anticholinergic (SAAC) should be added to SABA for older children in severe cases (hospital admission decreased by 27% and 74% when compared to SABA and SAAC alone, respectively). Continuous nebulization, addition of magnesium sulfate to SABA, and levosalbutamol compared to salbutamol cannot be recommended in routine practice.

The Evidence for Intravenous Theophylline Levels between 10-20mg/L in Children Suffering an Acute Exacerbation of Asthma: A Systematic Review

Background Intravenous theophyllines are a second line treatment for children suffering an acute exacerbation of asthma. Various guidelines and formularies recommend aiming for serum theophylline levels between 10-20mg/l. This review aims to assess the evidence underpinning this recommendation. Methods A systematic review comparing outcomes of children who achieved serum theophylline concentrations between 10-20mg/l with those who did not. Primary outcomes were time until resolution of symptoms, mortality and need for mechanical ventilation. Secondary outcomes were date until discharge criteria are met, actual discharge, adverse effects and FEV1. Data sources MEDLINE, CINAHL, CENTRAL and Web of Science. Search performed in October 2015. Eligibility criteria Interventional or observational studies utilizing intravenous theophyllines for an acute exacerbation of asthma in children where serum theophylline levels and clinical outcomes were measured. Findings 10 RCTs and 2 observational studies were included. Children with serum levels between 10-20mg/l did not have a reduction in duration of symptoms, length of hospital stay or need for mechanical ventilation or better spirometric results compared with levels <10mg/l. Levels above 20mg/l are not associated with higher rates of adverse effects. This study is limited due to heterogeneity in the way theophylline levels were reported and poor surveillance of adverse effects across studies. Conclusion Dosing strategies aiming for levels between 10-20mg/l are not associated with better outcomes. Clinicians should rely on clinical outcomes and not serum levels when using intravenous theophyllines in children suffering an acute exacerbation of asthma.

Pulse oximetry in children

Pulse oximetry is routinely used in hospitals in high-income settings, but its theoretical basis is often poorly understood. 1 This paper summarises the physiological background, technological basis and limitations of pulse oximetry.