Impact of the COVID-19 Pandemic on the Prescribing of Antiasthmatic Treatments in Portugal: A Nationwide Study

PURPOSE: The coronavirus disease 2019 (COVID-19) pandemic has had a profound impact on everyday life, the environment, and health care services. A shift from in-person medical appointments to telemedicine was a main adjustment. Such changes can have repercussions on the control and management of chronic respiratory diseases, such as asthma. The available data suggest that there was an overall decrease in asthma-related morbidities during the first year of the pandemic. Therefore, the goal of this study was to quantify the effects of the pandemic on the prescribing of antiasthmatic treatments in outpatient care (public and private health care). METHODS: This before–after study used a time series approach based on data from monthly prescriptions of antiasthmatic drugs (anti-inflammatory drugs and bronchodilators) dated between April 2018 and March 2021. An interrupted time series (ITS) design was used for assessing changes in antiasthmatic prescribing patterns in the short and long terms after COVID-19 was recognized as a pandemic. The results are complemented with seasonal autoregressive integrated moving average (sARIMA) models. FINDINGS: The ITS analysis showed a non-significant increase in antiasthmatic prescribing in the short term. In the long term, after the pandemic was declared, a statistically significant decrease was observed in the prescribing of antiasthmatics (in anti-inflammatory drugs and, more pronounced, in bronchodilators). In the sARIMA model, the mean monthly volume of antiasthmatic prescriptions was 18.1% lower than predicted. The numbers of months outside of the 95% CIs were different between anti-inflammatory drugs (1 month) and bronchodilators (7 months). IMPLICATIONS: The prescribing of antiasthmatic drugs in the long term was significantly decreased with the COVID-19 pandemic, with a greater effect in the case of bronchodilators.