Re-exploration of the optimal threshold for restrictive transfusion after hip fracture: a multicenter prospective...

Restrictive transfusion is recommended in patients undergoing hip fracture surgery. However, the evidence regarding the optimal threshold for transfusion remained uncertain.

In this multicenter prospective cohort, we enrolled participants who received surgical treatment of a hip fracture and were aged 65 years or older from 2017 to 2023. The restrictive transfusion of red blood cells (RBCs) with a threshold at the hemoglobin level <8 g/dl was the standard of care during the study period. When periodic shortage of blood existed, the threshold was adjusted to <7 g/dl as a priori-defined coping strategy. The primary outcome was all-cause mortality within one year after surgery.

In this study, 3356 and 892 patients received standard care (threshold at the hemoglobin level <8 g/dl) and alternative care (threshold at the hemoglobin level <7 g/dl), respectively. Patients in the alternative care group had a similar incidence of death within one year compared with patients in the standard care group (157 [17.6%] patients versus 575 [17.1%] patients), with an adjusted hazard ratio (HR) of 1.01 (95% confidence interval [CI] 0.85 to 1.21, P = 0.885). For subgroup analysis of patients with cardiovascular disease (CVD) at baseline, death occurred in 53 (22.6%) patients of the alternative care group and 182 (20.8%) of the standard care group, with an adjusted HR of 1.45 (95% CI 1.05 to 1.99, P = 0.023).

In patients without baseline CVD, adjusting the threshold for transfusion from the standard level (hemoglobin level <8 g/dl) to an alternative level (<7 g/dl) might be a safe practice in coping periodic blood shortage. In patients with baseline CVD, the standard threshold remained recommended. Future randomized clinical trials were warranted by the current study.