(034) Risk of safety outcomes associated with the long-term use of oral corticosteroids: A nested case-control study of 1 million patients with atopic dermatitis

Background: The use of oral corticosteroids (OCSs) for extended period may lead to various adverse events (AEs). Nevertheless, the risk of AEs especially in atopic dermatitis (AD) patients associated with the long-term use of OCS (LTOC) has not been comprehensively investigated, especially lacking evidence on duration.

Objectives: To assess the association between LTOC and the various AEs among patients with AD

Methods: We conducted a nested case-control study including patients with AD aged 18 years and older using Health Insurance Review and Assessment service (HIRA) database between 2012 and 2021 in South Korea. From our cohort, patients diagnosed with an adverse outcome (cases), composite of osteoporosis, fracture, type 2 diabetes mellitus, hyperlipidemia, hypertension, myocardial infarction, stroke, heart failure, avascular necrosis, cataract, or glaucoma were matched to patients never diagnosed (controls) using risk-set sampling. The LTOC was defined as cumulative 1) >30 days of OCS use per year (30-LTOC) and 2) >90 days of OCS use per year (90-LTOC), with >5mg daily prednisolone-equivalent dose, evaluated annually throughout the exposure ascertainment period. The LTOC group is patients with a history of the LTOC for at least 1 year, and all remaining patients were defined as no LTOC group. Additionally, we performed analyses with the number of cumulative years of the LTOC, also with the maximum of consecutive years of the LTOC. We conducted multivariable conditional logistic regression analyses to estimate adjusted odds ratios (ORs) with 95% confidence intervals (CIs), controlling for potential confounders.

Results: From 572,534 patients, we identified 164,809 cases and 328,303 controls. Overall, the risk of adverse outcomes was not increased with 30-LTOC while the risk was higher with 90-LTOC (OR 1.11, 95% CI 1.01-1.23). Each cumulative or consecutive year of LTOC resulted in marginally increased risk of having an AE (1.06, 0.999-1.13 and 1.06, 0.997-1.13, respectively). Significant associations were identified in the analysis for individual outcome of fracture, hyperlipidemia, hypertension, myocardial infarction, avascular necrosis and cataract. Generally consistent findings observed across a range of subgroup and sensitivity analyses.

Conclusions: In this nationwide study, we found long-term use of OCS over 90 days in patients with AD was associated with slightly increased risk of composite adverse outcome. Based on these observed risks, OCS should be used with more caution and the duration of usage should be minimized, possibly, under 90 days during a year. Moreover, health care providers should thoroughly prescribe OCS in AD patients for prolonged period based on risk-benefit assessment with continued monitoring for any potential adverse events.