Impact of Asthma Exacerbations on Health Status in Patients with Severe Asthma

Rationale: Asthma exacerbations constitute a considerable part of disease burden in patients with severe uncontrolled asthma. However, the impact of exacerbations is challenging to quantify. The St George’s Respiratory Questionnaire (SGRQ), a measure of health status in obstructive airway disease, was measured at baseline and end of treatment in a 32 week phase III clinical trial of mepolizumab for treatment of severe asthma with a history of exacerbations (MENSA).

Methods: In this post-hoc analysis, we examined the impact of exacerbations in 2 ways (1) baseline SGRQ scores by exacerbation history (≤2 compared with >2) and (2) change in SGRQ scores for subjects with and without exacerbations during treatment. All patients entering the trial had a history of at least two severe asthma exacerbations in the prior 12 months.

Results: Among subjects with a history of ≤2 exacerbations, mean baseline SGRQ total score was 42.5 compared to 49.4 for those a history of >2 exacerbations (p<0.0001). Among patients not experiencing an exacerbation during the study, SGRQ total score at 32 weeks was 28.5 compared to 41.5 for subjects experiencing >1 exacerbations during study treatment (p<0.0001) with changes of -15.4 and -8.0, respectively. Similar patterns were observed for SGRQ domain scores.

Conclusions: The observed differences in SGRQ total and domain scores for subjects with history of exacerbations at baseline or experiencing an exacerbation during the study substantially exceeded the accepted minimum clinically important difference of 4. These differences in SGRQ score demonstrate a substantial health impact of exacerbations. Funding: GSK (NCT01691521)