“…In many of the publications, the study population is heterogeneous and consists of primary immune deficiencies, SCT and patients on different chemotherapy regimens. The severity of the clinical condition of patients in these studies also varies considerably; the proportion of patients who were ventilated with or without multiorgan failure in critical-care units, when the SLB was performed, ranged from 2 to 100% [12,13,14,15,16,17,18,19,23]. Our study demonstrated a lower yield of SLB in comparison to the results presented by others, with the estimation of the yield of SLB ranging from 33 to 69% across studies [5,13,14,15,16,17,18,19].…”