Background/Aims: To determine the feasibility of undertaking a dietary supplementation trial to evaluate fish oil as an adjunct therapy for chronic obstructive pulmonary disease (COPD).
Methods: A double-blind, randomised controlled parallel trial was undertaken to compare the effects of fish oil versus corn oil placebo (six 1 g capsules/day orally for 16 weeks) on respiratory function, dyspnoea, functional exercise capacity and well being. The following a priori feasibility criteria were evaluated: ability to recruit 40 participants within 52 weeks, 80% participant retention rate, and a moderate sized effect in at least three outcome measures.
Results: Of 267 potential participants, 101 declined to participate and 91 were unable to be contacted. Of those willing to participate 62 were excluded at the telephone screening, the most common reasons being participants were taking fish oil (n=20), did not have COPD (n=10), were participating in another study (n=7) or, at visit 1, had a significant bronchodilator response (n=13). Only13 were enrolled (7 in the initial 52 weeks), 9 of whom completed the 16 week intervention. Participants withdrew from the study due to illness (n=2), injury unrelated to the study (n=1) or an adverse event (n=1). There was one moderate sized change (impulse oscillometry, effect size -0.56).
Conclusions: This preliminary trial did not meet the pre-determined key feasibility criteria, which raises doubts as to whether we can ascertain the efficacy of omega-3 supplementation in COPD using this approach.
Funding source: None