This study assessed the effectiveness of a leukotriene receptor antagonist (LTRA) in two pragmatic randomised controlled trials over a 2-year period in primary care practices across the UK.

The first trial compared LTRAs with inhaled glucocorticoids as the first-line treatment in asthma.

The second trial compared the addition of LTRAs versus the addition of long-acting β2-agonists in patients already using inhaled glucocorticoids with asthma.

All treatments led to significant improvements in the primary outcome measure: the mini Asthma Quality of Life Questionnaire. At 2 months, the LTRA was found to be equivalent in both studies. At 2 years, there was a trend towards equivalence between treatment groups although scores fell outside of their pretest definition of equivalence...