CRD summary

This review assessed the efficacy and safety of nebulisers, pressurised metered-dose inhalers and dry powder inhalers as delivery systems for beta-agonists, anticholinergic agents and corticosteroids. The authors concluded that the delivery devices can be equally effective. Given the risk of studies being underpowered and the limited consideration of quality, the robustness of the authors' conclusions is somewhat unclear.

Authors' objectives

To compare the efficacy and safety of nebulisers, pressurised metered-dose inhalers (MDIs) with or without a spacer or holding chamber, and dry powder inhalers (DPIs) as delivery systems for beta-agonists, anticholinergic agents and corticosteroids.

Searching

MEDLINE, EMBASE and the Cochrane Library were searched for English language articles. The search terms were reported though the dates of the searches were unclear.

Study selection

Assessment of study quality

The authors did not state that they assessed validity.

Data extraction

The authors did not report how the data were extracted. Mean scores and standard deviations were extracted for individual studies and used to calculate the weighted mean difference and 95% confidence interval. Where an outcome was assessed at more than one time point, the most recent time point was used. Where more than one outcome was assessed, the outcome that was highest in the specified hierarchy (ranging from FEV1 at the top of the hierarchy to heart rate, pulse rate and increase in heart rate at the bottom) was used.

Methods of synthesis

Results of the review

Fifty-nine RCTs were included (n not reported).

Over 20 separate meta-analyses were conducted across the different populations and settings for the various delivery devices. There were no statistically significant differences between delivery devices in any of the meta-analyses conducted. The authors stated that there was very little heterogeneity in any of the analyses (data were not reported).

Authors' conclusions

The various devices used for the delivery of bronchodilators and steroids can be equally efficacious. There is no clear basis for selecting one device over another.

CRD commentary

The review addressed a defined review question. The review question was broad and only inclusion criteria for the interventions of interest and study design were specified. Some relevant electronic databases were searched. Details of the search terms were provided though the search dates were not. No attempts were made to locate unpublished studies and only English-language studies were included; there is therefore a risk of publication and language bias. Two reviewers were involved in selecting studies, which helps minimise error and bias, though it was unclear how the data were extracted.

The statistical pooling was probably appropriate as the authors stratified studies based on the devices being compared, study population and setting. The authors stated that there was no significant heterogeneity, though this data and details of the method of pooling were not reported. Individual studies were not quality assessed. The quality of the evidence was graded, but this was based primarily on study design and the criteria that were used to distinguish the quality of the RCTs were unclear. Many of the studies were small and the authors pointed out that many might have been underpowered to detect an effect. In addition, many of the studies conducted in a laboratory setting were designed to be equivalence studies. Given the risk of the studies being underpowered and the limited consideration of quality, the robustness of the authors' conclusions is somewhat unclear.

Implications of the review for practice and research

Practice: The authors stated that several factors should be considered when selecting a delivery device for individuals with asthma and COPD. In particular, the availability of the device; the clinical setting; the age of the patient and their ability to use the device appropriately; the use of multiple medications; costs and reimbursement; drug administration time; convenience and durability; and patient and physician preference. Further recommendations about specific devices and settings were made.

Research: The authors did not state any specific implications for research. However, they did highlight the lack of information in the included studies on who is likely to use specific devices properly, patient preference, and other factors that are important in choosing a delivery device. This may be a useful area for future research

Bibliographic details

Dolovich MB, Ahrens RC, Hess DR, Anderson P, Dhand R, Rau JL, Smaldone GC, Guyatt G. Device selection and outcomes of aerosol therapy: evidence-based guidelines. Chest 2005; 127(1): 335-371. [PubMed: 15654001]

Original Paper URL

http://journal.publications.chestnet.org/article.aspx?articleid=1083082

Other publications of related interest

This additional published commentary may also be of interest. Horner SD. Review: various devices for delivery of aerosol treatment can be equally efficacious. Evid Based Nurs 2005;8:106.

Indexing Status

Subject indexing assigned by NLM

MeSH

Adrenergic beta-Agonists /administration & dosage; Anti-Asthmatic Agents /administration & dosage; Cholinergic Antagonists /administration & dosage; Equipment Design; Evidence-Based Medicine; Glucocorticoids /administration & dosage; Humans; Inhalation Spacers; Metered Dose Inhalers; Nebulizers and Vaporizers /standards; Practice Guidelines as Topic; Pulmonary Disease, Chronic Obstructive /drug therapy; Randomized Controlled Trials as Topic

AccessionNumber

12005008536

Database entry date

30/06/2006

Record Status

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.