Predicting Risk of Morbidities Associated with Oral Corticosteroid Prescription for Asthma.

Background: Oral corticosteroids (OCS) are commonly used to treat asthma but increase the risks for multiple morbidities; reducing OCS exposure may benefit patients. We analysed independent risk factors and longitudinal changes in OCS usage among patients with asthma to predict future risks of OCS-related adverse outcomes. Methods: Optimum Patient Care Research Database United Kingdom primary care electronic medical records (EMR) from January 1990 to June 2021 were used to select adults (18-93 years) with asthma who had follow-up data from ≥2 years before to ≥3 years after an index visit for active symptoms; this date was defined by the largest pre-visit to post-visit change in mean annual OCS use. OCS usage during every follow-up year was categorised as none, low (mean <2 prescriptions/year), or high (mean ≥2 prescriptions/year). Pre-index to post-index changes between usage categories were calculated. Risk modelling selected cohorts without 17 morbidities (documented pre-index) reported to be associated with OCS exposure, including type 2 diabetes, osteoporosis, hypertension, and pneumonia. Cox regression analyses selected published risk factors associated with each condition and available in EMR for inclusion in proportional hazards models. Results: The pre-index to post-index OCS usage category remained unchanged in 38.6% of patients, increased in 39.2%, and decreased in 22.2%, with 20.7% having no further OCS prescriptions. In models, the risks of all adverse outcomes increased with projected categoric OCS use; for example, hazard ratios for a one-category increment (none to low, low to high) were 1.55 (1.42-1.69) for type 2 diabetes, 1.56 (1.36-1.78) for post-menopausal osteoporosis, 1.05 (1.00-1.10) for hypertension, and 1.67 (1.52-1.83) for pneumonia (all p < 0.001). Conclusion: OCS exposure in this primary care asthma population usually continued longitudinally. Our models predict increased risk of multiple morbidities with higher projected OCS exposure. These findings support early initiation of strategies to minimise OCS use in asthma.