Prehospital use of inhaled corticosteroids in covid-19: a systematic review and meta-analysis

Introduction: Studies of hospitalized patients with COVID-19 have found varying clinical outcomes associated with underlying respiratory conditions and inhaled corticosteroid use. We performed a systematic review to summarize the effect of the pre-hospital use of inhaled corticosteroids on the clinical outcomes in patients with COVID-19. Methods: A comprehensive literature accrual was conducted across the WHO, CDC, and LitCovid PubMed COVID-19 databases from inception until June 30th, 2022. The Overall mortality was the primary outcome, and the secondary outcomes were the need for intensive care unit (ICU) admission and the need for invasive mechanical ventilation (IMV). All included studies were observational and reported the desired outcomes with pre-hospital use of ICS in COVID-19 patients. Data analysis was performed using Review Manager Software, version 5.2 to evaluate the combined odds ratio (OR) with respective 95% confidence intervals (CI) using a random-effects model. Results: Nineteen studies assessed mortality and were included in the meta-analysis. A total of 1,122,329 patients were included, of which 10,466 patients died (2,289 out of 824,005 in ICS arm patients and 8,177 out of 298,324 in the non-ICS arm), resulting in the unadjusted odds of death (OR 1.36, 95% CI 1.09-1.70, I2=82%). However, In the subgroups analyses of COPD patients (8 studies; 598 out of 106,659 in the ICS arm and 353 out of 44,496 in the non-ICS arm) and Asthma patients (7 studies; 705 out of 714,126 in the ICS arm and 179 out of 222,577 in the non-ICS arm), significantly increased risk of death was not shown (OR 1.20, 95% CI 0.93-1.57, I2=32%, OR 1.61, 95% CI 0.97-2.66, I2=82% respectively). There were no significantly increased odds in the assessed secondary outcomes; ICU admission (13 studies, OR 1.11, 95% CI 0.82-1.51, I2=84%), need for mechanical ventilation (7 studies, OR 1.21, 95% CI 1.00-1.45, I2=0%). Conclusions: Prehospital use of ICS in COVID-19 patients is associated with higher odds of overall mortality in unadjusted analysis. However, this was not shown in the subgroup of patients with a history of COPD or Asthma. Other clinical outcomes such as the need for ICU admission and mechanical ventilation show similar trends. Future research with well-designed clinical trials is needed to validate our findings.