Effectiveness of fluoroquinolone antimicrobials in addition to tetracyclines for Japanese spotted fever: A retrospective analysis using a national inpatient database.

OBJECTIVES

This study aim to evaluate the effectiveness of fluoroquinolone (FQ) antimicrobial therapy in combination with tetracyclines (TCs) in patients with Japanese spotted fever (JSF) using a nationwide inpatient database in Japan.

METHODS

We identified hospitalized patients diagnosed with JSF who were enrolled in the Japanese Diagnosis Procedure Combination inpatient database from July 2010 to March 2021. Patients who received FQ plus TC on the day of admission were compared with patients who received TC alone on the day of admission, using inverse probability of treatment weighting. The primary outcome was in-hospital mortality. Secondary outcomes were in-hospital complications, total hospitalization costs, and length of hospital stay.

RESULTS

We identified 1060 eligible patients. Of these, 434 (41%) received FQ plus TC on the day of admission and 626 (59%) received TC alone on the day of admission. Inverse probability of treatment weighting showed no statistically significant differences between the groups in in-hospital mortality, in-hospital complications, total hospitalization costs, and length of hospital stay.

CONCLUSION

This study did not show any significantly improved effectiveness using FQ antimicrobials in combination with TCs for treating JSF. Clinicians may need to be cautious in administering FQ and TC antimicrobials concomitantly in routine practice.