Impact of Guideline-Based Asthma Treatment on Health Services Use in Singapore Before and During COVID-19 Outbreak

Introduction: To date, the role of standard asthma care in reducing asthma-related health services use (HSU) during the COVID-19 pandemic remains unclear. This study examined the impact of guideline-based asthma treatment on the use of asthma-related emergency department (ED) visits, polyclinic visits (total visits and urgent visits characterized by nebuliser use) before and during the pandemic. Methods: Data from April 2017 to October 2020 was obtained from the National University Health System, one of the three healthcare clusters in Singapore. Using generalized linear models, we estimated the joint effects of the ratio of preventer to reliever dispensations (PRR) and COVID-19 on asthma-related ED visits per hospital per month, total asthma-related polyclinic visits and asthma-related urgent polyclinic visits per clinic per month. Results: Findings show that before the onset of COVID-19, for every 0.5 unit increase in PRR, the number of asthma-related ED visits and urgent polyclinic visits decreased by 12.9% (95% CI: -13.0% to -12.9%) and 6.8% (95% CI: -6.9% to -6.7%), respectively, whereas total asthma-related polyclinic visits increased by 1.0% (95% CI: 0.9% to 1.0%). During the pandemic, a 0.5 unit increase of PRR decreased the number of asthma-related ED visits, urgent and total polyclinic visits by 16.9% (95% CI: -17.0% to - 16.9%), 9.3% (95% CI: -9.5% to -9.2%) and 0.7% (95% CI: -0.8% to -0.7%), respectively. Discussion: These findings suggest that regardless of the COVID-19 pandemic, an increase in PRR consistently reduced the frequency of asthma-related urgent and emergent care, although it barely influenced routine asthma follow-up visits. In order to understand how guideline-based asthma management affects asthma-related health services use during the COVID-19 pandemic, in this study, we examined the pattern and impact of asthma medication utilisation (ie, the ratio of preventer to reliever dispensations) on asthma-related total polyclinic visits, urgent polyclinic visits and emergency department visits, and compared such effects before and during COVID-19 outbreak. We found a significant reduction in reliever medication dispensations and asthma-related total polyclinic visits, urgent polyclinic visits and emergency department visits in Singapore during the COVID-19 pandemic, as compared to the pre-pandemic period. We also observed a rapid increase in the ratio of preventer to reliever dispensations in Singapore since early 2019 which accelerated during the COVID-19 pandemic. Our finding suggests that this increase could be associated with a significant reduction in asthma-related urgent and emergent care. This effect persisted both before and during the COVID-19 pandemic. These current findings suggest that guideline-based asthma management, which can be delivered through primary care and self-care, is able to reduce asthma-related urgent care even in a global pandemic with restrained healthcare resources.