BACKGROUND: Asthma is a common long-term breathing condition that affects approximately 300 million people worldwide. People with asthma may experience short-term worsening of their asthma symptoms; these episodes are often known as 'exacerbations', 'flare-ups', 'attacks' or 'acute asthma'. Oral steroids, which have a potent anti-inflammatory effect, are recommended for all but the most mild asthma exacerbations; they should be initiated promptly. The most often prescribed oral steroids are prednisolone and dexamethasone, but current guidelines on dosing vary between countries, and often among different guideline producers within the same country. Despite their proven efficacy, use of steroids needs to be balanced against their potential to cause important adverse events. Evidence is somewhat limited regarding optimal dosing of oral steroids for asthma exacerbations to maximise recovery while minimising potential side effects, which is the topic of this review.
OBJECTIVES: To assess the efficacy and safety of any dose or duration of oral steroids versus any other dose or duration of oral steroids for adults and children with an asthma exacerbation.
SEARCH METHODS: We identified trials from the Cochrane Airways Group Specialised Register (CAGR), ClinicalTrials.gov (www.ClinicalTrials.gov), the World Health Organization (WHO) trials portal (www.who.int/ictrp/en/) and reference lists of all primary studies and review articles. This search was up to date as of April 2016.
SELECTION CRITERIA: We included parallel randomised controlled trials (RCTs), irrespective of blinding or duration, that evaluated one dose or duration of oral steroid versus any other dose or duration, for management of asthma exacerbations. We included studies involving both adults and children with asthma of any severity, in which investigators analysed adults and children separately. We allowed any other co-intervention in the management of an asthma exacerbation, provided it was not part of the randomised treatment. We included studies reported as full text, those published as abstract only and unpublished data.
DATA COLLECTION AND ANALYSIS: Two review authors independently screened the search results for included trials, extracted numerical data and assessed risk of bias; all data were cross-checked for accuracy. We resolved disagreements by discussion with the third review author or with an external advisor.We analysed dichotomous data as odds ratios (ORs) or risk differences (RDs) using study participants as the unit of analysis; we analysed continuous data as mean differences (MDs). We used a random-effects model, and we carried out a fixed-effect analysis if we detected statistical heterogeneity. We rated all outcomes using the GRADE (Grades of Recommendation, Assessment, Development and Evaluation) system and presented results in 'Summary of findings' tables.
MAIN RESULTS: We included 18 studies that randomised a total of 2438 participants - both adults and children - and performed comparisons of interest. Included studies assessed higher versus lower doses of prednisolone (n = 4); longer versus shorter courses of prednisolone (n = 3) or dexamethasone (n = 1); tapered versus non-tapered courses of prednisolone (n = 4); and prednisolone versus dexamethasone (n = 6). Follow-up duration ranged from seven days to six months. The smallest study randomised just 15 participants, and the largest 638 (median 93). The varied interventions and outcomes reported limited the number of meaningful meta-analyses that we could perform.For two of our primary outcomes - hospital admission and serious adverse events - events were too infrequent to permit conclusions about the superiority of one treatment over the other, or their equivalence. Researchers in the included studies reported asthma symptoms in different ways and rarely used validated scales, again limiting our conclusions. Secondary outcome meta-analysis was similarly hampered by heterogeneity among interventions and outcome measures used. Overall, we found no convincing evidence of differences in outcomes between a higher dose or longer course and a lower dose or shorter course of prednisolone or dexamethasone, or between prednisolone and dexamethasone.Included studies were generally of reasonable methodological quality. Review authors assessed most outcomes in the review as having low or very low quality, meaning we are not confident in the effect estimates. The predominant reason for downgrading was imprecision, but indirectness and risk of bias also reduced our confidence in some estimates.
AUTHORS' CONCLUSIONS: Evidence is not strong enough to reveal whether shorter or lower-dose regimens are generally less effective than longer or higher-dose regimens, or indeed that the latter are associated with more adverse events. Any changes recommended for current practice should be supported by data from larger, well-designed trials. Varied study design and outcome measures limited the number of meta-analyses that we could perform. Greater emphasis on palatability and on whether some regimens might be easier to adhere to than others could better inform clinical decisions for individual patients.
There are still no new answers to an old problem. Interesting meta-analysis but no interesting practical conclusion.
As a family physician, I believe this is important information, even though the study is telling us that we really don't know whether this is an optimal regimen for oral steroids used acutely.
This review is of minimal use in that it cannot confirm current practice or affirm the clinical utility of of one treatment over another.
A meta-analysis showing that there are not a lot of data to meta-analyze! We must wait until a well-designed clinical study addresses specifically this question, and in the meantime, we can use whatever scheme of administration.
Confirms with strong methodology current clinicians' judgement: we don't know, 1) whether and 2) how much variations in days or dose may alter outcome. I feel a bit surprised and disappointed that Point 2) has not been examined and presented with some helpful Detail.
The article tells us that there is no clear answer as to the superiority of one steroid regimen (type, dose, duration) over another. The evidence is generally of low quality and too heterogeneous to combine. The question is relevant but the answer remains unknown.
The question being considered is of direct relevance to general paediatricians and Respiratory physicians. Like many Cochrane reviews, there is insufficient evidence to provide definite answers to the question of dose and duration of steroids in acute flare-ups of asthma. The fact that the evidence is insufficient is newsworthy for practitioners.
As an ED physician, my colleagues and I am are concerned with adherence to post-ED visit medications. Therefore, we often use dexamethasone in the setting of acute asthma exacerbations, especially in children likely to be discharged home.
Results of this and any meta-analysis are always dependent on the quality of the individual studies with regards to the clinical questions. It's difficult to reach conclusions when the quality of studies is not great.
This is a review which concludes that we do not have sufficient evidence to make any definitive statements.