Study design

The double-blind placebo-controlled trial took place from April 2015 until January 2016 and consisted of 3 visits in a time frame of 4 to 8 weeks. Participation in the study was voluntary. Prior to the commencement of the first visit (Screening visit, V1), written informed consent was required from each subject or from the parents of children under the age of 18 years.

At V1, the participants’ inclusion and exclusion criteria were confirmed, a lung function test administered using the MasterScreen spirometer, a skin prick test (SPT) performed, eNO measured and an asthma control questionnaire (ACQ) provided to participants.

On the second (V2, Randomization) and third visit (V3, End of study) a lung function test was conducted, eNO measured, an exercise challenge in a cold chamber (ECC) administered and blood collected. If the patient fulfilled the inclusion criteria `FEV<sub>1</sub> decrease ≥15% in the ECC` at V2, they were randomised to one of the two study arms (interventional group with sc-LCPUFA supplementation or placebo group). V3 was performed after 4 weeks of supplementation. The study flow chart with assessments is shown in Fig.​Fig.1.1. The study was approved by the ethics committee of Goethe University (reference number 360/14) Clinical trials registration number: {"type":"clinical-trial","attrs":{"text":"NCT02410096","term_id":"NCT02410096"}}NCT02410096.

Flowchart of study design with assessments