VARIATION IN USE OF BLOOD TRANSFUSIONS AMONG PATIENTS UNDERGOING PRIMARY TOTAL HIP ARTHROPLASTY AT DANISH HOSPITALS

Abstract

Introduction: We examined the risk of blood transfusion in patients undergoing THA at 21 different orthopaedic departments in Denmark.

Material and Methods: Patients with primary THA (n=21,773) registered in the Danish Hip Arthroplasty Registry between 1999 and 2006 were identified. Data on use of blood transfusion was collected from the Danish Transfusion Data Base (DTDB). The outcome was defined as red blood cell transfusion (yes/no) within 7 days after surgery. Modified Poisson regression analyses were used to estimate the risk of red blood cells transfusion (RR) and a 95% confidence interval (CI) adjusting for possible confounding factors including patient related factors (age, gender, comorbidity and diagnosis for primary THA) and surgery related factors (type of anestesia, type of osiffication prophylaxis type of operation, duration of surgery, and duration of admission. The risk of blood transfusion for each department was compared with the general risk of blood transfusion for all departments.

Results: Overall, red blood cells transfusion was given to 8,162 of 21,773 patients (37%) (range between 16% and 64%, depending on department). After adjusting for different patient–and surgery-related factors, the adjusted RRs differed from 1.24 (95% CI, 2.07–3.43) to 0.52 (95% CI, 0.4–0.69) using all departments as reference. Coefficient of variation was 23%.

Conclusions: Substantial differences in the risk of red blood cells transfusion among THA patients were found when comparing a sample of Danish orthopaedic departments. The differences in use of transfusions appeared not to be explained by a range of patient – and surgery – related factors and may thus reflect true differences in transfusion practice.