Incidence of serious respiratory tract infections and associated characteristics in a population exposed to immunosuppressive therapies: a register-based population study.

BACKGROUND

Immunosuppressive therapies are associated with a risk of infections. Nevertheless, their incidence in this population remains unclear. This study aims to determine the incidence of serious respiratory tract infections (SRI) in a population exposed to immunosuppressive therapies.

METHODS

Data from a representative sample of the French healthcare claims from 01/01/2014 to 12/31/2019 were analyzed. Exposure to immunosuppressive therapy was defined by the dispensation of drugs through community pharmacies or in hospitals. SRI diagnosis was based on ICD-10 codes from hospitalization records. A cohort analysis was performed to estimate standardized SRI incidence rates. A nested case-control analysis within this cohort was used to study the characteristics associated with SRI.

RESULTS

We identified 24,122 individuals exposed to immunosuppressive therapies, among which 1,559 developed SRI, resulting in a standardized incidence rate of 1,398 per 100,000 person-years. In this population, the risk of SRI was associated with a history of cancer (OR 2.68, 95% Confidence Intervals (CI) 2.24-3.21; p < 0.001), chronic respiratory disease (2.62, 95%CI 2.17-3.16; p < 0.001), end-stage renal failure (2.38, 95%CI 1.37-4.13; p = 0.003), neurodegenerative diseases (1.52, 95%CI 1.07-2.17; p = 0.026), diabetes (1.44, 95%CI 1.14-1.82; p < 0.001), psychiatric diseases (1.27, 95%CI 1.06-1.52; p < 0.001), and cardiovascular diseases (1.26, 95%CI 1.04-1.52; p = 0.002). Compared to corticosteroids alone, the risk of SRI was lower in individuals treated with conventional synthetic disease-modifying anti-rheumatic drugs (csDMARD) only (0.44, 95%CI 0.25-0.78; p < 0.001).

CONCLUSION

In the population exposed to immunosuppressive therapies, a history of chronic disease is associated with an increased risk of SRI. This risk is lower in those receiving csDMARD alone than corticosteroids alone.