In‐hospital mortality among patients with invasive non‐group A β‐hemolytic Streptococcus treated with clindamycin combination therapy: a nationwide cohort study

Aim Combination treatment with clindamycin is recommended in patients with invasive group A Streptococcus infection; however, whether the same treatment is effective in invasive group B Streptococcus and S. dysgalactiae subspecies equisimilis infections remains unknown. We aimed to investigate whether clindamycin added to standard of care therapy would be effective in patients with invasive non‐group A β‐hemolytic Streptococcus infections. Methods This was a nationwide retrospective cohort study using the Japanese Diagnosis Procedure Combination inpatient database focusing on the period between 2010 and 2018. We extracted data on patients diagnosed with sepsis due to non‐group A β‐hemolytic Streptococcus . One‐to‐four propensity score‐matching was undertaken to compare patients who were treated with clindamycin within 2 days of admission (clindamycin group) and those who did not (control group). The primary outcome was in‐hospital mortality. Results We identified 3754 eligible patients during the study period. The patients were divided into the clindamycin ( n  = 296) and control groups ( n  = 3458). After one‐to‐four propensity score matching, we compared 289 and 1156 patients with and without clindamycin, respectively. In‐hospital mortality did not significantly differ between the two groups (9.7% versus 10.3%; risk difference 0.3%; 95% confidence interval, –3.5% to 4.2%). Conclusions This nationwide database study showed that combination therapy involving the use of clindamycin was not associated with lower in‐hospital mortality in patients with invasive non‐group A β‐hemolytic Streptococcus .