Incidence and utility of follow-up blood cultures in cancer patients with gram-negative bacteremia.

Benefit of follow-up blood cultures (FUBC) in cancer patients with gram-negative bacteremia (GNB) is unknown. Multicenter, retrospective review was performed in adult cancer patients with GNB between January and December 2018. Primary outcome was FUBC incidence. Chi-square, t-tests/Wilcoxon rank-sum, and bivariate regression (logistic/Poisson) analyses compared secondary outcomes (catheter removal, ID consultation, antibiotic duration, length stay, mortality) between patients with versus without FUBC. Of 52 patients with GNB, majority (35/52; 67%) received ≥1 FUBC (mean per patient 3.6, SD 4.3, range 0-29). Majority FUBC had no growth (157/173; 90.8%). Rates of catheter removal and ID consultation were similar between groups (P > 0.05). Patients with FUBC had greater LOS (mean 21 vs 15 days; coefficient = 0.31, CI 0.17-0.45), longer duration of antibiotics (mean 13 vs 11 days, coefficient 0.19, P = 0.013), but no mortality difference (P = 1). FUBC are frequently performed yet infrequently positive in cancer patients with GNB, but were associated with increased LOS and antibiotic duration.