title: Prevalence of potential underlying aetiology of macrocytic anaemia in Dutch general practice.
abstract: Macrocytic anaemia (MCV ≥ 100 fL) is a relatively common finding in general practice. However, literature on the prevalence of the different causes in this population is limited. The prevalence of macrocytic anaemia and its underlying aetiology were analysed in a general practice population. The potential effect of the different aetiology on survival was also evaluated.
  
  
  
  Between the 1st of February 2007 and the 1st of February 2015, patients aged 50 years or older and presenting to their general practitioner with a newly diagnosed anaemia, were included in the study. Anaemia was defined as haemoglobin level below 13.7 g/dL in men and below 12.1 g/dL in women. A broad range of laboratory tests was performed for each patient. The causes of anaemia were consequently determined by two independent observers based on the laboratory results.
  
  
  
  Of the 3324 included patients, 249 (7.5 %) displayed a macrocytic anaemia and were subsequently analysed. An underlying explanation could be established in 204 patients (81.9 %) with 27 patients (13.2 %) displaying multiple causes. Classic aetiology (i.e. alcohol abuse, vitamin B12/folic acid deficiency, haemolysis and possible bone marrow disease) was found in 115 patients. Alternative causes (i.e. anaemia of chronic disease, iron deficiency, renal anaemia and other causes) were encountered in 101 patients. In addition, a notable finding was the median gamma GT of 277 U/L in patients diagnosed with alcohol abuse (N = 24, IQR 118.0-925.5) and 23 U/L in the remaining cohort (N = 138, IQR 14.0-61.0). The distribution of gamma GT values was statistically different (P < 0.001). Five year survival rates were determined for six categories of causes, ranging from 39.9 % (95 % CI 12.9-66.9) for renal anaemia to 76.2 % (95 % CI 49.4-103.0) for the category multiple causes.
  
  
  
  In addition to classic explanations for macrocytosis, alternative causes are frequently encountered in patients with macrocytic anaemia in general practice.
authors.affiliation: Department of Clinical Chemistry, Albert Schweitzer Hospital, Albert Schweitzerplaats 25, room F3126, 3300, AK, Dordrecht, The Netherlands. k.stouten@asz.nl.|Department of Internal Medicine, Albert Schweitzer Hospital, Albert Schweitzerplaats 25, 3300, AK, Dordrecht, The Netherlands. k.stouten@asz.nl.
authors.forename: Karlijn
authors.initials: K
authors.lastname: Stouten
authors.affiliation: Department of Clinical Chemistry, Albert Schweitzer Hospital, Albert Schweitzerplaats 25, room F3126, 3300, AK, Dordrecht, The Netherlands.
authors.forename: Jurgen A
authors.initials: JA
authors.lastname: Riedl
authors.affiliation: Department of Haematology, St Elisabeth Hospital, Hilvarenbeekse Weg 60, 5022, GC, Tilburg, The Netherlands.
authors.forename: Jolanda
authors.initials: J
authors.lastname: Droogendijk
authors.affiliation: Department of Clinical Chemistry, Albert Schweitzer Hospital, Albert Schweitzerplaats 25, room F3126, 3300, AK, Dordrecht, The Netherlands.|Department of Clinical Chemistry, Admiraal de Ruyter Hospital, 's-Gravenpolderseweg 114, 4462, RA, Goes, The Netherlands.
authors.forename: Rob
authors.initials: R
authors.lastname: Castel
authors.affiliation: Department of Biostatistics, Erasmus Medical Centre, 's-Gravendijkwal 230, 3015, CE, Rotterdam, The Netherlands.
authors.forename: Joost
authors.initials: J
authors.lastname: van Rosmalen
authors.affiliation: General practitioner at General Medical Practice van Houten, Tromplaan 49, 3342 TR, H.I., Ambacht, The Netherlands.
authors.forename: Ron J
authors.initials: RJ
authors.lastname: van Houten
authors.affiliation: Department of Clinical Chemistry, Beatrix Hospital, Banneweg 57, 4204, AA, Gorinchem, The Netherlands.
authors.forename: Paul
authors.initials: P
authors.lastname: Berendes
authors.affiliation: Department of Haematology, Erasmus Medical Centre, 's-Gravendijkwal 230, 3015, CE, Rotterdam, The Netherlands.
authors.forename: Pieter
authors.initials: P
authors.lastname: Sonneveld
authors.affiliation: Department of Internal Medicine, Albert Schweitzer Hospital, Albert Schweitzerplaats 25, 3300, AK, Dordrecht, The Netherlands.
authors.forename: Mark-David
authors.initials: MD
authors.lastname: Levin
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000437:Alcoholism / Q000097:blood / Q000150:complications / Q000453:epidemiology*; D018798:Anemia, Iron-Deficiency / Q000453:epidemiology; D000748:Anemia, Macrocytic / Q000097:blood / Q000453:epidemiology* / Q000209:etiology*; D001855:Bone Marrow Diseases / Q000150:complications / Q000453:epidemiology*; D058006:General Practice / Q000706:statistics & numerical data*; D006461:Hemolysis; D006801:Humans; D007674:Kidney Diseases / Q000150:complications / Q000453:epidemiology; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D015995:Prevalence; D015996:Survival Rate; D014806:Vitamin B 12 Deficiency / Q000150:complications / Q000453:epidemiology*; D005723:gamma-Glutamyltransferase / Q000097:blood
chemical_list: D005723:gamma-Glutamyltransferase
keywords: Erythrocytes; Erythropoiesis; General practice; Laboratory markers; Macrocytic anaemia; Survival