Sample size
Using a two-sample t-test based on expected improvement on total nasal symptoms score (TNSS) a power calculation was performed. Assuming a 2 out of 12 points improvement in total dSS and a standard deviation of 2 points, aimed at a power of 0.80 and using a type 1 error rate α level of 0.05, the calculated sample size was 32. A power calculation using CSMS was not performed prior to study start. Patients treated with Depomedrol had a median (IQR) CSMS score of 1.6 (1.3–2.4) and in the placebo group 2.5 (1.8–3.0).