3.3 Frequency and time to first and repeated surgery in different subgroups
The mean cumulative count with 95% CIs for ESS for all incident CRSwNP patients during an eight-year follow-up is presented in Figure 3A. At one year follow-up, the mean number of ESS per patient was 0.44 (95% CI 0.43 – 0.44) ESS. At five years of follow-up, the mean cumulative count per patient was 0.59 (95% CI 0.58 – 0.60) ESS. Both asthma status and asthma severity had an impact on the mean cumulative count for ESS, and a CRSwNP patient with severe controlled asthma had undergone on average 0.68 (95% CI 0.63 – 0.73) ESS within three years after the diagnosis. The corresponding count for a severe uncontrolled asthma patient was 0.80 (95% CI 0.70 – 0.90) ESS within three years after the diagnosis, Figure 3B.
Overall, during the follow-up period, 8 673 patients out of the total 18 563 incident CRSwNP patients (46.7%) had undergone an ESS to treat the polyps. The probability of having an ESS was 40.6% (95% CI 39.9 – 41.3 %) for the CRSwNP patients during the first year after the diagnosis of polyps (Figure 4A). The median time from the diagnosis of polyps to first ESS in patients with mild to moderate asthma was 20 months, while the median time for patients with severe uncontrolled asthma was 11 months. Patients in all asthma groups were more likely to have the first surgery earlier compared to non-asthma patients. Still, for the non-asthma CRSwNP patients, the probability of ESS was 41.5 % (95% CI 40.6 – 42.3%) within the first two years after the diagnosis of polyps, Figure 4B.
Out of the 8 673 CRSwNP patients who had an ESS, 7 227 (83.3%) had only one ESS, whereas 1 446 (16.6%) patients had two or more sinus surgeries. Overall, the probability for at least one revision ESS during follow-up within two years after the first ESS was 10.6% (95% CI 10.0 – 11.3%) (Figure 5A). Figure 5B shows that any asthma comorbidity increased the likelihood of having another surgery. In addition, the patients with more severe asthma were more likely to have the revision surgery earlier compared to non-asthma CRSwNP patients. The probability of repeated ESS within two years after the first ESS was 9.5% (95% CI 8.7 - 10.2%), 12.6% (95% CI 11.2 – 14.0%), 13.5% (95% CI 10.3 – 16.7%) and 17.9% (95% CI 11.9 – 23.5%), for patients with no asthma, mild to moderate asthma, severe controlled asthma, and severe uncontrolled asthma, respectively.