As part of our ongoing seminar series, the Centre of Excellence in Severe Asthma hosted Prof. Helen Reddel for a webinar on “How to Design and Interpret Studies of Non-Pharmacological Interventions for Asthma” on 28 July, 2015.
Presentation Summary:
Non-pharmacological approaches are an important aspect of asthma management. These approaches are used in combination with medications. Approaches include avoidance of environmental exposures, physical activity and educational interventions.
High-level evidence is available for some non-pharmacological approaches. These include avoidance of tobacco smoke exposure, physical activity, healthy diet and avoidance of medications that worsen asthma. Unfortunately, high-level evidence is limited for most non-pharmacological strategies.
To generate high-quality evidence, careful consideration must be made to study design and analysis. Useful guidance for non-pharmacological treatment trials is available in from the CONSORT Group (Boutron, Ann Intern Med, 2008).
This presentation outlines factors that to consider when in non-pharmacological trials for asthma. Key factors include a clear statement of the research question, the choice of comparator groups, outcome measures, study blinding and patient involvement. Through careful consideration of these factors high quality research of non-pharmacological interventions is possible.
Key Points:
- Asthma management is not just about drug treatment
- Many non-pharmacological strategies have been proposed in asthma management
- High-quality evidence for many of these interventions is limited
- High-level evidence is available for avoidance of tobacco smoke exposure and medications that worsen asthma and promotion of physical activity and healthy diet
- Quality issues in non-pharmacological studies relate to study design, selection of patient populations, recruitment, intervention approaches, outcome measures, analysis and meta-analysis
- A CONSORT checklist extension provides guidance for non-pharmacological treatment trials (Boutron, Ann Intern Med, 2008)
- When planning a study, it is important to consider whether the study is a proof-of-concept (efficacy) versus an implementation study (effectiveness)
- Selection of the treatment comparator can be active or inactive
- Active comparators include current best practice, matched interventions for non-specific components and alternative treatment
- Inactive comparators include placebo or sham treatment
- Selection of the same comparator groups as other clinical trial studies can facilitate meta-analysis
- It is desirable that comparator groups be matched for the level of contact with health professionals, as healthcare contact has effects on outcomes
- Including sufficient detail in study methods is important, to ensure reproducibility across sites and to support blinding
- Regulatory requirements are lacking for non-pharmacological interventions, compared to drugs and medical devices
- There is less ability to blind non-pharmaceutical interventions, which increases the potential for sampling bias. Blinding the specific study hypothesis can help with this concern
- How the intervention is described, and patient expectation of outcomes can have large effects on study outcomes
- In asthma studies, treatment outcomes for symptom control and exacerbations are often discordant
- Short-term responses do not necessarily reflect long-term safety in asthma trials
- Asthma symptoms are modifiable by placebo or sham treatment, but are often used as outcome measures in trials of non-pharmacological treatments
- Example case: A pharmacist-delivered inhaler technique education intervention resulted in improved inhaler technique, asthma control and asthma-related quality of life (Basheti et al. Patient Educ Couns, 2008)
- Example case: A double-blinded RCT trial of breathing technique exercises with shallow nasal breathing failed to improve asthma outcomes, when compared to non-specific exercises with no evidence of benefit (Slader, Thorax, 2006)
- High quality research of non-pharmacological interventions is possible using standardised outcomes, achieving blinding where possible and considering cost-effectiveness
- Involving patients in study concept and design can be beneficial
About Prof. Helen Reddel:
Prof. Reddel’s research focuses on strategies to improve the management of airways disease, and population level monitoring of asthma and COPD outcomes. She has a strong focus on improving communication between patients and health professionals, and on making guidelines not only evidence-based, but also practical and patient-centred.
She is Chair of the Science Committee of the Global Initiative for Asthma (GINA), a member of the Guidelines Committee for the Australian Asthma Handbook, and clinical adviser to the Australian Centre for Airways disease Monitoring (ACAM).
