Step 1: Assess Asthma Severity

No Level 1 evidence was identified to support the recommendations in this step. The recommendation for the assessment of asthma severity reflects consensus and current clinical practice. The review found no randomised controlled trials or meta-analyses on questions related to Step 1 recommendations. It is known that data exist in the form of non-randomised studies (i.e. Levels 3 and 4) but these were not searched for as part of the review. Many of the questions related to Step 1 are suitable for future research.