Patients
This study was carried out of the rhinitis or rhinosinusitis patients visiting Departments of Otorhinolaryngology at the Hospital District of Helsinki and Uusimaa (HUS), Finland. The study (nro 31/13/03/00/2015) was approved by the ethical committee of the Hospital District. Ethics committee provided an approval that there was no need for written informed consent for this retrospective follow-up study.
The inclusion criterion of the initial patient population (n = 5080) was the ICD-10 diagnosis of J30., J31., J32., J33. or J01 registered in outpatient visits for the years 2005, 2007, 2009, 2011 or 2013. Longitudinal data of random patient samples were collected from electronic health records (EHR), so that the sample size was the same for each sampling year and each month of the sampling year. The last data collection day of the follow-up data was 31.9.2019. CRS was defined as having the diagnosis codes of J33. and/or J32. ESS was defined by the operation codes (Table S2). The baseline visit was defined as the first visit, and baseline ESS was the first ESS, found in the EHR at the given sampling time. Revision ESS was defined as ESS that was performed after the baseline ESS during the follow-up.
A total of 114/790 (14.7%) CRS patients underwent revision ESS in (mean±stdev) 30.3±31.0 months after the baseline ESS (Figure S3A, Table S4). Of the revised patients 91 had one revision ESS and 23 patients had two or more revisions (Figure S3B).