METHODS
Study design
This was a single-centre, double-blind, randomized,
placebo-controlled, three-arm, parallel-group
trial, undertaken at the Persahabatan Central
Hospital, Jakarta, to evaluate the efficacy and safety
of Echinacea alone or in combination with ascorbic
acid, zinc and selenium in COPD outpatients for the
treatment of an exacerbation episode caused by an
acute URTI. Patients received treatment for 2 weeks
and had blood samples taken for the measurement
of biomarkers and COPD symptoms scored at the
clinic before and after treatment. In-between both
visits and during the 4 weeks post-treatment,
patients had to score daily on exacerbation symptoms
in patient diaries. The study protocol was
compliant with the declaration of Helsinki and was
approved by an appropriate Ethical Committee