Association between perioperative change in red cell distribution width and mortality in patients with brain tumor craniotomy

An elevated preoperative red cell distribution width (RDW) is associated with adverse prognostic outcomes in various diseases. However, the correlation between changes in RDW (ΔRDW) and the prognosis following brain tumor craniotomy remains unclear. Accordingly, this study aimed to investigate the prognostic significance of perioperative changes in RDW in patients undergoing brain tumor craniotomy. This retrospective cohort study included patients undergoing craniotomy for brain tumors at West China Hospital, Sichuan University, from January 2011 to March 2021. We defined perioperative changes in RDW: group A (non-significant RDW changes, ΔRDW ≤0.4%), group B (drop in RDW, ΔRDW < −0.4%), and group C (rise in RDW, ΔRDW >0.4%). The relationship between the changes in RDW and all-cause mortality was analyzed by categorizing the patients according to perioperative ΔRDW (RDW at postoperative one week – RDW at admission). The present study included a total of 9589 patients who underwent craniotomy for the treatment of brain tumors. A rise in RDW was significantly associated with increased mortality, with an adjusted OR of 3.56 (95% CI: 2.56–4.95) for 30-day mortality and 1.57 (95% CI: 1.33–1.85) for one-year mortality compared to those with non-significant RDW changes (ΔRDW ≤0.4%). Conversely, a decrease in RDW showed no significant association with 30-day mortality (adjusted OR: 1.04, 95% CI: 0.53–2.04) and one-year mortality (adjusted OR: 1.18, 95% CI: 0.92–1.53). These findings were also supported by restricted cubic spline, which shows that increases in RDW were significantly associated with lower survival rates compared to stable RDW levels during the follow-up period. Among patients undergoing craniotomy for a brain tumor, a rise in RDW was associated with 30-day mortality and higher long-term mortality risks, even if patients' admissions for RDW values were within the normal range. It was worth noting that maintaining stable RDW levels during this period was associated with better survival.