Moderate to severe anemia at admission increases the risk of complications in patients over 60 years with hip fracture.

Background: Anemia frequently occurs in patients with hip fractures and represents a risk factor that can potentially be altered. To evaluate the association between admission anemia and complications in older hip fracture patients while exploring the potential impact of anemia on complications from the perspective of overall, operation and non-operation.

Methods: This retrospective study enrolled in-patients over 60 years old with hip fractures from January 2020 to November 2023. At admission, anemic patients were identified as having a hemoglobin level below 12 g/dL in females and 13 g/dL in males. Anemia was further classified as mild, moderate, or severe. Data encompassing demographics, comorbidities, medications, information on fracture and surgery, and complications were collected.

Results: A total of 462/679 patients had anemia, including 348, 105, and 9 with mild, moderate, and severe anemia, respectively. A total of 281 individuals experienced complications, including 212 and 69 with and without operation, respectively. Multivariate regression analysis identified anemia as a greater risk for acute heart failure (OR = 2.056, p = 0.037, 95% CI 1.043-4.052) than non-anemia. Moderate to severe anemia was a significant risk factor for any complication (OR = 1.584, p = 0.028, 95% CI 1.050-2.390), ≥ 2 (OR = 2.364, p = 0.001, 95% CI 1.443-3.872) or 3 (OR = 2.311, p = 0.022, 95% CI 1.131-4.720) complications, delirium (OR = 2.301, p = 0.018, 95% CI 1.156-4.579), venous thromboembolism (OR = 2.031, p = 0.042, 95% CI 1.025-4.025), and acute heart failure (OR = 2.095, p = 0.016, 95% CI 1.145-3.834), compared with mild to non-anemia. Similar results were observed in operated patients, while anemia and its severity were not associated with complications in non-operated patients.

Conclusion: Moderate to severe anemia caused complications in elderly hip fracture patients, but it was not observed in non-operated individuals. These findings would support orthopedic physicians' hierarchical management of anemic patients.