The aetiology and prevalence of preoperative anaemia in patients undergoing major surgery (ALICE): an international, prospective, observational cohort study
Suma Choorapoikayil, David M. Baron, Donat R. Spahn, Sigismond Lasocki, Daniela Boryshchuk, Lusine Yeghiazaryan, Martin Posch, Elvira Bisbe, Philipp Metnitz, Martin Reichmayr, Kai Zacharowski, Patrick Meybohm, Patrick Meybohm, Laura Alvarez-Velasquez, Georg Baumgarten, Olaf Baumhove, Lara Beladdale, Lea Valeska Blum, Suma Choorapoikayil, Samuel De Leeuw van Weenen, Dina El Naggar, Kristina Graf, Karlheinz Gürtler, Frank Hentschel, Phillipp Helmer, Lotta Hof, Pascal Knuefermann, Mischa J Kotlyar, Timo Ludwig, Gregor Massoth, Michael Meier, Patrick Meybohm, Vanessa Neef, Florian Piekarski, Nadine Straßberger-Nerschbach, Markus Velten, Christoph Wiesenack, Maria Wittmann, Kai Zacharowski, Kai Zacharowski, Philippe Aries, Myriam Belkacemi Rezzaoui, Hélène Beloeil, Loïc Benoit, Anne-Helene Boivin, Corentin Bonnet, Matthieu Boisson, Rachida Boukhari, Fanny Bounes, Maeva Campfort, Marc Danguy Des Deserts, Olivier Desebbe, Vincent Ehinger, Julia Fink, Denis Frasca, Baptiste Gaudriot, Aude Jeannin, Maria Lahlou Casulli, Julien Lanoiselée, Sigismond Lasocki, Mael Le Gall, Morgan Le Guen, Maxime Leger, Sabrina Ma, Pierre Massenat, Aurélie Merlin, Vincent Minville, Didier Moreau, Anne-Cécile Neau, Camille Parent, Xavier Pichon, Florian Pineau, Florence Prunier, Jean Rabet, Celin Ravry, Jean Christophe Rigal, Emmanuel Rineau, Bertrand Rozec, Julia Rubin, Jean-Luc Soubirou, Audrey Roode Tibere, Brendan Urvoy, Marc Vercruysse, Mickael Vourch, Matthew Hart, Matthew Jenkins, McAllister Davina, Renee Hope, Stephen Hillier, Walston Martis, John Shepard, Jessica Smith, Phillip Tarrant, Jonathan Termaat, Kathrin Travis, Seema Vinish, Martis Walston, Alfredo Abad Gurumeta, Ane Abad Motos, Hector Aguado
Abstract
BACKGROUND: Preoperative anaemia is a major risk factor for perioperative morbidity. Because iron deficiency is widely assumed to be the main cause of anaemia in surgical patients, treatment efforts have focused mostly on iron supplementation. However, the aetiology of anaemia is multifactorial. To further understand the underlying causes and consider a comprehensive approach to anaemia management, we studied the prevalence and aetiology of preoperative anaemia in patients undergoing major surgery. METHODS: This prospective, multicentre, observational cohort study was done in 79 hospitals in 20 countries on five continents; patients were aged at least 18 years, undergoing major surgery, and had a postoperative in-hospital stay of at least 24 h. Patients donating autologous blood before surgery were excluded. Data were extracted from the electronic hospital information system and from self-reported information during preoperative examination. The primary outcomes were the prevalence of anaemia, defined as haemoglobin less than 120 g/L for women and less than 130 g/L for men, analysed in all participants, and the aetiology of anaemia, analysed only in patients with anaemia for whom aetiology could be confirmed. The study was registered with ClinicalTrials.gov (NCT03978260) and is complete. FINDINGS: Between Aug 26, 2019, and Dec 26, 2021, 2830 patients undergoing major surgery were recruited and 2702 patients were included in the analysis (1417 [52·4%] were male, 1279 [47·3%] were female, and six [0·2%] had gender dysphoria). Overall, 856 (31·7%, 95% CI 31·2-32·2) patients had preoperative anaemia. Among 782 patients with preoperative anaemia, for whom the presence of at least one aetiology could be confirmed, 432 (55·2%, 48·9-61·6) had iron deficiency, 60 (7·7%, 6·6-8·7) had vitamin B12 deficiency, 113 (14·5%, 12·2-16·7) had folate deficiency, 68 (8·7%, 8·1-9·3) had chronic kidney disease, and 48 (6·1%, 4·5-7·8) had anaemia resulting from another cause; patients could be assigned to multiple aetiologies. Across male and female sex, all age groups, and all countries, iron deficiency was the aetiology with the highest prevalence. INTERPRETATION: The prevalence of preoperative anaemia in patients in this study who were undergoing major surgery is high. Iron deficiency is the primary cause of this anaemia; however, the substantial prevalence of vitamin B12 and folate deficiencies demands immediate attention and action. FUNDING: None. TRANSLATIONS: For the Afrikaans, Albanian, Arabic, French, German, Greek, Italian, Korean, Portuguese, Romanian, Slovenian, Spanish, and Turkish translations of the abstract see Supplementary Materials section.