Inhaled corticosteroids’ effect on COVID-19 patients: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND: More than six million people died due to COVID-19, and 10-15% of infected individuals suffer from post-covid syndrome. Corticosteroids are widely used in the management of severe COVID-19 and post-acute COVID-19 symptoms. This study synthesizes current evidence of the effectiveness of inhaled corticosteroids (ICS) on mortality, hospital length-of-stay (LOS), and improvement of smell scores in patients with COVID-19. METHODS: We searched Embase, Web of Science, PubMed, Cochrane Library, and Scopus until Aug 2022. The Cochrane risk of bias tool was used to assess the quality of studies. We evaluated the effectiveness of ICS in COVID-19 patients through measures of mortality, LOS, alleviation of post-acute COVID-19 symptoms, time to sustained self-reported cure, and sense of smell (visual analog scale (VAS)). RESULTS: Ten studies were included in the meta-analysis. Our study showed a significant decrease in the LOS in ICS patients over placebo (MD = -1.52, 95% CI [-2.77 to -0.28], p-value = 0.02). Patients treated with intranasal corticosteroids (INC) showed a significant improvement in VAS smell scores from week three to week four (MD =1.52, 95% CI [0.27 to 2.78], p-value = 0.02), and alleviation of COVID-related symptoms after 14 days (RR = 1.17, 95% CI [1.09 to 1.26], p-value < 0.0001). No significant differences were detected in mortality (RR= 0.69, 95% CI [0.36 to 1.35], p-value = 0.28) and time to sustained self-reported cure (MD = -1.28, 95% CI [-6.77 to 4.20], p-value = 0.65). CONCLUSION: We concluded that the use of ICS decreased patient LOS and improved COVID-19-related symptoms. INC may have a role in improving the smell score. Therefore, using INC and ICS for two weeks or more may prove beneficial. Current data do not demonstrate an effect on mortality or time to sustained self-reported cure. However, the evidence is inconclusive, and more studies are needed for more precise data.