Power calculation
ThIlo, ARDS, high disability
REGRESSION, SECONDARY, ARDS
The ThIlo trial was powered for the primary endpoint (effectiveness of iloprost in ARDS). In this secondary analysis, a post-hoc power calculation was done to estimate the risk of high disability at day 180. The power calculation was based on a binary logistic regression model. An observed group size of 144 patients (144 with COVID-19 and 44 without COVID-19) was used for the power calculation. The outcome of high disability, which occurred in 57% of patients, requires an OR of 3.1 (or OR: 0.32) to achieve a power of 80% with an alpha of 5%. The calculation was performed using the software PASS 2020.