Real‐world characterisation of patients with chronic rhinosinusitis with nasal polyps with and without surgery in England

To characterise the real‐world burden of chronic rhinosinusitis with nasal polyps (CRSwNP) in the UK, stratified by number of surgeries.


| INTRODUCTION
Chronic rhinosinusitis with nasal polyps (CRSwNP) is characterised by chronic inflammation of the paranasal sinuses and inflammatory outgrowths of sino-nasal tissue, 1 with elevated blood eosinophil levels a common feature of recurrent CRSwNP. [2][3][4] Symptoms include nasal blockage, loss of smell and rhinorrhoea, [5][6][7] which can have a substantial impact on health-related quality of life, daily activity and ability to work. [8][9][10][11] Previous estimates of CRSwNP prevalence in the general population have ranged from 1.1% in the United States to 4.3% in Finland. [12][13][14][15] The current standard of care for CRSwNP includes intranasal corticosteroids, saline nasal douching and short courses of systemic (i.e., oral or injectable) corticosteroids (SCS), with endoscopic sinus surgery considered in those who fail to achieve symptom control. 13 While surgery is effective in many cases, some patients experience recurrent disease, despite post-operative treatment. These patients often undergo multiple surgeries, with numerous courses of systemic corticosteroids, worsening quality of life and increased healthcare resource utilisation (HCRU). 8,[16][17][18][19][20] For patients who experience recurrent disease despite surgery, treatment with a biologic may be considered. 13

| Objectives
There are currently limited data on the burden of CRSwNP in the UK, including patient characteristics and HCRU, and the prevalence of sur-

gery. A previous study by the Chronic Rhinosinusitis Epidemiology
Study group looked at the burden of revision surgery in patients with CRS in the UK. However, this study recruited patients referred to secondary care and may overestimate the need for both primary and secondary surgery. 19 This study used data from a primary care database with hospital linked data to characterise the real-world burden of CRSwNP and identify patients with unmet needs in the UK. These data would be informative for health policy decision making in terms of understanding how many and which patients may be eligible for biologic therapy, as per current European Position Paper on Rhinosinusitis and Nasal Polyps recommendations. 13 2 | METHODS  Figure S1).

| Participants
Eligible patients were ≥18 years of age at index and had ≥365 days of continuous enrolment prior to the index date and ≥180 days postindex date. Patients were excluded if they had a diagnosis of CRSwNP or surgery for NP during the baseline period or a diagnosis of cystic fibrosis at any time during the study period. This study used fully de-identified retrospective medical record data, and as such, was not classified as research involving human participants. Therefore, institutional review board approval and informed consent were not required.

Key points
1. This retrospective cohort study characterised the realworld burden of chronic rhinosinusitis with nasal polyps (CRSwNP) in the UK stratified by number of surgeries following an initial NP diagnosis.

| Patient demographics, clinical characteristics and comorbidities
Compared with patients without surgery, patients with ≥2 surgeries were younger and more likely to be male, have comorbid asthma or NERD and have severe asthma (Table 1).
In total, 36.4% of patients had a blood eosinophil count measurement at baseline. Geometric mean blood eosinophil counts increased as the number of surgeries increased, as did the proportion of patients with blood eosinophil counts of ≥300 cells/μL (Table 1).

| CRSwNP-related treatments and all-cause HCRU in the first 90 days of follow-up
During the first 90 days of follow-up, patients with surgery at any time during follow-up had more oral corticosteroid (OCS) and oral antibiotic use and less topical corticosteroid use than those with no surgery ( Table 2). The mean number of all-cause primary care visits was similar among patients with or without surgery during follow-up.
However, patients with surgery had slightly higher mean numbers of inpatient and outpatient visits compared with those who had no surgery. Mean all-cause HCRU visits increased with increasing number of surgeries ( Table 2) (Table 3). For HCRU visits, the most notable increases during the 90-day post-surgery period between patients undergoing their second versus first surgery were in primary care visits and outpatient visits. While surgical complications were rare, the most commonly reported complication patients experienced within 90 days of surgery was bleeding (first surgery: 1.5%; second surgery: 1.4%) ( Table 3).       23 As such, the small proportion of patients requiring repeat surgery in the current study is reassuring and suggests that the prevalence of patients with severe uncontrolled CRSwNP in the UK who may require additional therapy to achieve disease control is low.
Although the proportion of patients with multiple surgeries during follow-up was low, the duration between first and second and second The overall prevalence of CRSwNP reported in this study (.5%) was lower than previous estimates from population-based studies (1.0%-4.3%), 12-15 however the current study identified clinically relevant cases of CRSwNP, therefore the prevalence could be expected to be lower than in population-based studies. [12][13][14][15] Additionally, the current study's estimate may be lower due to the non-inclusion of patients managing their condition using over the counter medication therefore not seeking health care for their CRSwNP.
The study is subject to the limitations inherent to a retrospective cohort study using healthcare data. First, patient and NP surgery identification relied on diagnosis and procedure codes introducing the possibility of CRS misdiagnosis. Second, the full details of NP surgeries were not always captured in procedure codes. Additionally, for several of the procedure codes used, it is uncertain if they were specific to NP surgery only, however, as the study only included patients with CRSwNP diagnosis it is unlikely that overestimation of surgery occurred. This is also the case with SCS, it is unclear from CPRD Med-