3.1 CRSwNP prevalence and incidence
Altogether, 53 119 fulfilled the study diagnosis criteria for CRSwNP, and 18 563 (35%) were incident patients. The results show a continuous increase in lifetime prevalence of CRSwNP patients from 602.2 patients per 100 000 population in 2012 to 856.7 patients per 100 000 population in 2019 (p < 0.001) (Figure 1 and 2A). In the same time period, the incidence decreased from 50.5 patients per 100 0000 in 2012 to 43.4 patients per 100 000 in 2019 (p = 0.004).
The mean annual incidence of CRSwNP per 100 000 population are visualized in Figure 2. Patients aged 50-59 and 60-69 years had the highest incidence of CRSwNP (Figure 2B). The mean annual incidence was 96.4/100 000 population (standard deviation (SD): 6.4) for patients aged 50-59 years and 103.2/100 000 population (SD: 4.6) for patients aged 60-69 years. Males had a higher incidence than females and the difference is highlighted in the age groups from 30-39 onwards (Figure 2C and Figure 2D).