Systemic corticosteroid dispensing patterns and associated adverse outcomes among patients with chronic rhinosinusitis with nasal polyps

Chronic rhinosinusitis with nasal polyps (CRSwNP) symptoms are commonly treated with systemic corticosteroids (SCS) despite ambiguous clinical guidelines recommending the therapy’s use. SCS are strong anti-inflammatory medications with important related adverse outcomes. This thesis identified a cohort of CRSwNP patients and pharmacy claims to investigate dispensing patterns of SCS, factors associated with increased use, prescribing practices across healthcare providers, and association of SCS use with the incidence of adverse outcomes. Two studies were derived from this work. The first study was mainly descriptive and revealed variations in SCS prescribing practices among otolaryngologists and potential inappropriate SCS prescribing by general practitioners in the management of CRSwNP. Performing multinomial logistic regression, analyses showed patients residing in small population centres and rural areas were more likely to receive higher SCS doses. The second study, using time to event regression analysis, found that SCS use was associated with a higher risk of SCS-related adverse outcomes. In sensitivity analysis for individual outcomes, statistically significant associations were identified between SCS users compared with non-users and increased risk of pneumonia, hypertension, and cardio/cerebrovascular disease. In the study’s cumulative dose analysis, most adverse health outcomes showed increased risk among SCS users exposed to 0.5g to < 1g compared with those exposed to < 0.5g. A clear dose-response pattern with increasing cumulative dose was not observed. These findings underscore the need for standardized clinical guidelines, monitoring strategies for the prevention and early detection of adverse outcomes, and further research to identify safe and effective use of SCS among patients with CRSwNP.