Endoscopy 2014; 46(03): 257
DOI: 10.1055/s-0033-1359177
Letters to the editor
© Georg Thieme Verlag KG Stuttgart · New York

Is capsule endoscopy a useful modality for the emergency triage of upper gastrointestinal hemorrhage?

Long Xu
,
Meifang Huang
,
Bing Xia
Further Information

Publication History

Publication Date:
26 February 2014 (online)

We recently read the article by Gralnek et al. [1]. The authors conducted a proof-of-concept study, which we found quite interesting. However, we believe that two issues presented in the study warrant further review.

First, the authors found that capsule endoscopy provided less diagnostic accuracy than esophagogastroduodenoscopy (EGD), which is the gold standard for diagnosing upper gastrointestinal hemorrhage. As shown in Table 3 of the article, 28 patients (61 %) received different diagnoses from the two examinations. Simple Kappa was only 0.28 (95 %CI 0.07 – 0.49) when we performed a statistical analysis using SAS 9.0. The strength of agreement is poor when Kappa is less than 0.40 [2]. Thus capsule endoscopy was a poor tool for diagnosing upper gastrointestinal haemorrhage.

Secondly, the results of this study were not reliable due to the small sample size. According to the study of Springate et al. [3], the results of studies with one outcome cannot be considered reliable if the case number is less than 46. A larger simple size is therefore needed for this study, which examines multiple outcomes, including etiology (inflammation, ulcer or cancer) and location (esophagus, stomach, and duodenal bulb) of bleeding, though these outcomes were not clearly defined as such in the study.

In summary, this study concluded that capsule endoscopy identifies gross bleeding in the upper gastrointestinal tract and therefore may facilitate patient triage in an emergency department setting. We believe, however, that this conclusion is not reasonable due to the low diagnostic accuracy of capsule endoscopy and the small sample size. This question warrants further investigation in the form of well designed, unbiased prospective studies with larger sample sizes.

 
  • References

  • 1 Gralnek IM, Ching JY, Maza I et al. Capsule endoscopy in acute upper gastrointestinal hemorrhage: a prospective cohort study. Endoscopy 2013; 45: 12-19
  • 2 Sierra F, Cárdenas A. Evidence-based medicine (EBM) in practice: agreement between observers rating esophageal varices: how to cope with chance?. Am J Gastroenterol 2007; 102: 2363-2366
  • 3 Springate SD. The effect of sample size and bias on the reliability of estimates of error: a comparative study of Dahlberg’s formula. Eur J Orthod 2012; 34: 158-163