The prevalence of coeliac disease is approximately 1 % [
1‐
5]. However, 75 % of cases remain undiagnosed [
6], possibly due to its insidious onset, and patients do not always have symptoms. Moreover, the sensitivities of the endoscopic features of coeliac disease are limited as they may not always be present or easily recognised [
7,
8]. One of the common presenting symptoms is anaemia, affecting 15–26.8 % of untreated patients [
9,
10]. It usually results from malabsorption, leading to iron, folate, and B12 deficiency [
11]. One way to increase the detection of coeliac disease is by screening individuals with iron deficiency anaemia, which affects 2–5 % of the general population in the developed world [
12,
13]. At the endoscopy setting, 2.6–8.7 % of patients presenting with anaemia are diagnosed with coeliac disease, although the data is sparse and mainly from small cohorts [
10,
14‐
18]. The current British Society of Gastroenterology (BSG) iron deficiency anaemia guidelines recommend routine screening for coeliac disease with tissue transglutaminase (TTG) and/or endomysial antibodies (EMA). This is based on the excellent negative predictive value of modern serological tests for coeliac disease. Individuals who are tested positive should then undergo a gastroscopy for duodenal biopsy to confirm the presence of coeliac disease [
19]. Anecdotally, the availability and utilisation of coeliac serology prior to endoscopy appears to be highly variable, thus committing clinicians to take duodenal biopsies if serology results are unavailable. However, this is an expensive way of case detection. A recent Swedish study [
10] showed that a routine duodenal biopsy strategy was ineffective, with a number needed to biopsy of 577 to detect one case of coeliac disease, spending more than €30,000 per case. In an attempt to target patients who require a duodenal biopsy, Hopper et al. [
20] devised a clinical decision tool using a combination of pre-endoscopy serological testing and symptom assessment. This algorithm had a 100 % sensitivity and negative predictive value in detecting coeliac disease when applied to 2000 prospectively recruited patients. Yet, the lack of serology availability prior to endoscopy in real clinical practice seemed to have precluded the widespread utilisation of this effective and cost saving clinical decision tool.
One method of filling the gap of unavailable serology is by using a point of care test at the point of endoscopy. Several point of care tests are now commercially available for clinicians and patients to purchase, mostly detecting TTG antibodies. Simtomax, a new point of care test for coeliac disease, is a finger prick test that provides rapid results within ten minutes. Simtomax detects coeliac disease with a unique combination of immunoglobulin A (IgA) and immunoglobulin G (IgG) antibodies against deamidated gliadin peptides (DGP) as well as the total level of IgA [
21]. This ensures that results are not affected by patients with IgA deficiency, which is more common in people with coeliac disease than the general population (2.6 % versus 0.14–0.2 %) [
22].
In this study, our aim was to evaluate the role of utilising a pre-endoscopy point of care test for coeliac disease, Simtomax, in iron deficiency anaemia in a cost saving model. Firstly, we reviewed the rates of adherence to the BSG guidelines on coeliac serological screening in iron deficiency anaemia in real clinical practice, to demonstrate the pre-endoscopy availability of serology. We then ascertained the sensitivities of Simtomax in detecting coeliac disease in iron deficiency, and established the economic impact of using Simtomax as a screening tool to target biopsy taking only in those tested positive for Simtomax. Finally, we explored whether routine duodenal biopsy would yield any alternative causes for iron deficiency anaemia other than coeliac disease, in order to evaluate whether using Simtomax to target biopsies only in Simtomax positive anaemic patients would miss other duodenal pathologies causing anaemia. We chose to review the duodenal histology of patients from the general population attending a non-coeliac specialised iron deficiency anaemia clinic at the Northern General Hospital, because the results would represent real world data without tertiary referral bias.