Use of Glucocorticoids and Risk of Community-Acquired Staphylococcus aureus Bacteremia: A Population-Based Case-Control Study

OBJECTIVE: To investigate whether the use of systemic glucocorticoids is a risk factor for community-acquired Staphylococcus aureus bacteremia (CA-SAB).

PATIENTS AND METHODS: We used population-based medical registries in Northern Denmark to conduct a case-control study including all adults with first-time CA-SAB and matched population controls from January 1, 2000, through December 31, 2011. Glucocorticoid users were categorized as current users (new or long-term use), former users, and nonusers. Using conditional logistic regression, we computed odds ratios (ORs) of CA-SAB according to glucocorticoid exposure, overall and by 90-day prednisolone-equivalent cumulative dose.

RESULTS: We identified 2638 patients with first-time CA-SAB and 26,379 matched population controls. Current glucocorticoid users experienced considerably increased risk of CA-SAB compared with nonusers (adjusted OR=2.48; 95% CI, 2.12-2.90). The adjusted OR was 2.73 (95% CI, 2.17-3.45) in new users, 2.31 (95% CI, 1.90-2.82) in long-term users, and much lower at 1.33 (95% CI, 0.98-1.81) in former users of glucocorticoids compared with nonusers. The risk of CA-SAB increased with higher 90-day cumulative doses. Compared with nonusers of glucocorticoids, the adjusted OR was 1.32 (95% CI, 1.01-1.72) for persons with a cumulative dose of 150 mg or less, 2.42 (95% CI, 1.76-3.33) for persons whose cumulative dose was greater than 500 to 1000 mg, and 6.25 (95% CI, 4.74-8.23) for persons with a cumulative dose greater than 1000 mg.

CONCLUSION: Glucocorticoid use was associated with a substantially increased risk of CA-SAB. The risk increased with higher cumulative dose, revealing a distinct dose-response relation.