The prevalence of pre-operative anaemia and an examination of its effect on transfusion practice between sexes: A multicentre retrospective study.

Pre-operative anaemia affects one third of patients presenting for surgery and is associated with increased peri-operative morbidity and mortality. Most studies on this subject make a distinction in acceptable haemoglobin level between sexes. We analysed data for patients undergoing major elective surgery, with pre-operative anaemia defined as haemoglobin <13 g/dL. Data was collected for 1074 patients, of whom 411 (38.3%) had pre-operative anaemia. The odds of red cell transfusion were significantly higher in patients with pre-operative anaemia, OR = 4.35 [95%CI OR: 3.0- 6.2]. Additional binary logistic regression results identified haemoglobin level, male gender and increasing age as independent predictors for red cell transfusion. The length of post-operative stay was also significantly higher in anaemic patients, those with lower haemoglobin, males and older patients. Women were twice as likely to have a haemoglobin < 13 g/dl as men. Women were also 3.55 times more likely not to be transfused despite being anaemic. This suggests differences in clinician's attitudes to transfusion limits in women, despite Blaudszun et al. 2018 showing that women with borderline anaemia (Hb 12-12.9 g/dL) are: more likely to be transfused; to be transfused more units of red cells; and to have longer lengths of hospital stay than non- anaemic women. A change in attitude to acceptable haemoglobin in women is needed. Increased clinician awareness of the associated morbidity of even a mild reduction in haemoglobin in women is required to result in more pro-active anaemia management pre-operatively and less allogenic red cell transfusion, shorter lengths of hospital stay and overall decreased morbidity.