Note from the National Guideline Clearinghouse (NGC): The National Institute for Health and Clinical Excellence (NICE) commissioned an independent academic centre to perform a systematic literature review on the technology considered in this appraisal and prepare an assessment report. The assessment report for this technology appraisal was prepared by the School of Health and Related Research (ScHARR), University of Sheffield. (See the "Availability of Companion Documents" field.)
Clinical Effectiveness
Search Strategy
The search aimed to identify all papers relating to childhood asthma inhalers and outcomes previously addressed in the systematic review by Brocklebank et al.* and published subsequent to publication of that review. The search also aimed to identify all papers that addressed childhood asthma inhalers (e.g. comparisons between different powder devices) or outcomes (e.g. patient preference/compliance, quality of life, unwanted effects, etc.) not covered in Brocklebank et al's review. An update of the Brocklebank et al. search on in vitro studies was also undertaken. All literature searches were conducted between April-July 2001.
* Brocklebank D, Ram F, Wright J, Barry P, Cates C, Davies L, Douglas G, Muers M, Smith D, White J. Comparison of the effectiveness of inhaler devices in asthma and chronic obstructive airways disease: a systematic review of the literature. Health Technol Assess. 2001;5(26):1-149.
Sources Searched
Fifteen electronic bibliographic databases were searched, covering biomedical, science, social science, health economic and grey literature (including current research). A list of databases is provided in Appendix 2 of the Assessment Report (see "Availability of Companion Documents" field).
In addition, the reference lists of the Brocklebank et al. review and other relevant articles were checked. Various health services research related resources were consulted via the Internet. These included health economics and Health Technology Assessment (HTA) organisations, guideline producing agencies, generic research and trials registers, and specialist asthma sites. A list of these additional sources is given in Appendix 3 of the Assessment Report (see "Availability of Companion Documents" field).
Search Terms
A combination of free-text and thesaurus terms were used. Asthma search terms were combined with generic terms regarding asthma inhalers (e.g., administration, inhalation; aerosols, powders, meter(ed) dose(s), mdi(s), pmdi(s), etc.), and limited to children. Searches were also conducted on named inhalers and spacers (e.g., Maxivent, Spacehaler, Accuhaler, etc.). Copies of the search strategies used in the major databases are included in Appendix 4 of the Assessment Report (see "Availability of Companion Documents" field).
Search Restrictions
Where possible (e.g., in the smaller databases), searches were not restricted by publication type or study design. However, methodological filters aimed at identifying guidelines, systematic reviews, clinical trials, economic evaluations, unwanted effects, compliance, and quality of life studies, were used in Medline (refer to Appendix 4 of the Assessment Report [see "Availability of Companion Documents" field] for details of the filters used). Searches for reviews, guidelines and clinical trials, were limited to 1998 onwards, as earlier studies had already been identified by the Brocklebank et al. review. No language restrictions were used.
Inclusion and Exclusion Criteria
Inclusion Criteria
Subjects: human patients aged between five and fifteen years with chronic asthma or experiencing a mild to moderate exacerbation (increased symptoms and reduced lung function requiring usual treatment delivery but at an increased frequency and/or dosage, not requiring emergency treatment or addition of oral steroids). For searches for "in vitro" evidence, the inclusion criteria omit "subjects."
Intervention: use of any one inhaler device to deliver bronchodilators (short and long acting beta2 –agonists, other adrenoceptor agonists, antimuscarinic bronchodilators), corticosteroids (beclometasone diproprionate, budesonide and fluticasone proprionate), cromoglycate, nedocromil, or combination therapy, for the routine management of chronic asthma. This includes any inhaler devices delivering drugs not licensed for the United Kingdom (UK) but included within the categories defined above (but such drug/device combinations will be specifically identified in the review).
Inhaler devices to include:
- Pressurised metered dose aerosols, using either chlorofluorocarbon (CFC) or hydrofluoroalkane (HFA) propellant, with or without a spacer (all sizes)
- Breath actuated metered dose aerosols, using either CFC or HFA propellant
- Breath actuated dry powder devices
Comparators: Alternative inhaler devices from the list above, but delivering the same form of medication, by generic drug, not by drug type, and at the equivalent dose level.
Exclusion Criteria
Interventions: Any interventions on drug efficacy in isolation from device used to deliver it.
Language: Any papers not available in the English language (as a rapid review, this review is subject to a very short time scale that precludes time for translation).
Time: No date limits will be imposed.
Studies available only as abstracts will also be excluded.