Use of asthma control indicators in measuring inhaled corticosteroid effectiveness in asthmatic smokers: a systematic review

The objective of this review is to explore how current research measures the effectiveness of inhaled corticosteroids (ICS) in smokers with asthma.PubMed, CINAHL and PsycINFO databases were searched for combinations of terms relating to asthma, tobacco use and ICS effectiveness.The search was limited to articles published between 2004 and 2015, in English language. Studies met inclusion criteria if reporting the use of guideline-based asthma control indicators to measure the therapeutic effects of ICS or ICS combination therapies. This review did not exclude articles based on study design. Data were extracted and summarized to describe how indicators were measured across studies in order to characterize and describe the effects of ICS in smokers.Thirteen studies were included in this review. Six of these 13 studies used only one indicator to measure asthma control in smokers and ICS was found to improve asthma in only one of six of these studies. Of studies evaluating combination therapy, three of four studies reported a therapeutic benefit to smokers. In these studies of combination therapy multiple indicators of control were measured to assess drug effects.To assess the therapeutic benefit of ICS drugs in smokers, multiple indicators should be measured to determine if current therapy is improving asthma control. Asthma therapy should then be adjusted based on the patient's current asthma status. The development of clinical treatment guidelines for asthmatic smokers may help clinicians make best-practice, evidence-based recommendations in order to optimize care for these patients.