Study designs of evaluations included in the review
Randomised, placebo-controlled, double-blind trials were included. Parallel and crossover studies were also accepted.
Specific interventions included in the review
Low-dose methotrexate (7.5 to 30 mg, once weekly) versus placebo.
Participants included in the review
The participants were adults or children with asthma who were dependent on daily oral corticosteroid therapy (at least 5 mg/day of prednisone or equivalent). Asthma was defined as a reversible airflow obstruction with at least a 15% improvement in forced expiratory volume in l second (FEVl) either spontaneously or after bronchodilator therapy.
Outcomes assessed in the review
The outcomes assessed were the reduction in oral corticosteroid use, the change in FEV1, and side-effects.
How were decisions on the relevance of primary studies made?
Two reviewers independently assessed and selected the trials for inclusion.