The percentage prevalence of gastrointestinal malignancy in 16 subgroups by sex, age and haemoglobin quartile of 720 patients with iron deficiency anaemia, Poole Hospital 2004–2012. The percentage prevalence of gastrointestinal malignancy in 16 subgroups by sex, age and haemoglobin quartile of 720 patients with iron deficiency anaemia, Poole Hospital 2004–2012. Haemoglobin quartile ranges are as in tables 1–3, and the prevalence figures are based on raw data. Angel Castro Silva et al. Frontline Gastroenterol doi:10.1136/flgastro-2013-100386 Copyright © BMJ Publishing Group Ltd & British Society of Gastroenterology. All rights reserved.