The Salford Lung Study on Asthma (SaLSA; n= 4725) demonstrates the additional benefits of fluticasone furoate and vilanterol combination, in terms of asthma control, when compared with optimised usual care in a broad patient population. Its strength lies in that it is an RCT that closely reflects clinical practice by use of existing electronic health records.
Patients with a general practitioner's diagnosis of symptomatic asthma and on maintenance inhaler therapy initiated treatment with either a once-daily inhaled combination of 100μg or 200μg fluticasone furoate with 25μg vilanterol or optimised usual care and were followed up for 12 months.
The primary endpoint was the percentage of patients who achieved an asthma control test (ACT) score of 20 or greater or an increase in ACT score from baseline of 3 or greater at 24 weeks (termed responders), in patients with a baseline ACT score of less than 20 (the primary effectiveness analysis population; reported above). At week 24, the adjusted mean ACT score increased by 4.4 points from baseline in patients initiated with fluticasone furoate and vilanterol, compared with 2.8 points in the usual care group (difference 1.6 ; 95% CI 1·3–2·0; p<0·0001).
A related commentary notes that in addition to confirming the known benefits and risks of inhaled corticosteroid/ long-acting β agonist (ICS/LABA) treatment in asthma, the innovative design of this trial provides insight into switching back from study treatment to usual care. Based on these findings, it can be expected that almost one in five patients commencing a new ICS/LABA combination will want to switch back to usual care—in the fluticasone furoate and vilanterol group, 463 (22%) of 2114 patients modified their study medication; of these, 381 (18%) switched back to usual care.