title: Negative capsule endoscopy for obscure gastrointestinal bleeding is closely associated with the use of low-dose aspirin.
abstract: OBJECTIVE
  Capsule endoscopy (CE) is used widely for determining the cause of obscure gastrointestinal bleeding (OGIB). However, negative findings still arise from CE examination. The aim of this study was to determine the factors associated with negative findings on CE in patients with OGIB.
  
  
  METHODS
  A total of 134 patients who underwent CE for overt (n = 104) or occult (n = 30) OGIB between October 2007 and April 2010 were included. The clinical backgrounds of the patients (age; sex; the use of anti-coagulant, anti-platelet drugs or NSAIDs; comorbidity and the timing of CE examination after bleeding) were noted.
  
  
  RESULTS
  The overall diagnostic yield of CE in detecting the relevant findings was 50% (n = 67). Multivariate analysis revealed that the use of anti-platelet drug and the timing of CE (≥ 16 days) were predictive factors for negative findings on CE (odds ratio 2.69 [1.01-7.21], p = 0.048 and odds ratio 2.32 [1.01-5.33], p = 0.047, respectively). Among the patients with the use of low-dose aspirin (LDA, n = 28) as anti-platelet drug, cessation of it before CE was the only predictive factor for negative findings on CE (odds ratio 12.0 [1.72-83.5], p = 0.012).
  
  
  CONCLUSIONS
  In the patients with OGIB, the use of LDA and the cessation of it before CE made it difficult to detect the cause of bleeding by CE. This might indicate that the source of OGIB related to LDA heals immediately after cessation of the drugs or is a very small lesion that could not be detected by CE.
authors.affiliation: Department of Medicine and Clinical Oncology, Graduate School of Medicine, Chiba University, Chiba-city, Japan.
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Matsumura
authors.forename: Makoto
authors.initials: M
authors.lastname: Arai
authors.forename: Sayuri
authors.initials: S
authors.lastname: Sazuka
authors.forename: Masaya
authors.initials: M
authors.lastname: Saito
authors.forename: Yoshie
authors.initials: Y
authors.lastname: Takahashi
authors.forename: Daisuke
authors.initials: D
authors.lastname: Maruoka
authors.forename: Takuto
authors.initials: T
authors.lastname: Suzuki
authors.forename: Tomoo
authors.initials: T
authors.lastname: Nakagawa
authors.forename: Toru
authors.initials: T
authors.lastname: Sato
authors.forename: Tatsuro
authors.initials: T
authors.lastname: Katsuno
authors.forename: Fumio
authors.initials: F
authors.lastname: Imazeki
authors.forename: Osamu
authors.initials: O
authors.lastname: Yokosuka
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage; D000925:Anticoagulants / Q000008:administration & dosage; D001241:Aspirin / Q000008:administration & dosage* / Q000009:adverse effects; D053704:Capsule Endoscopy; D005188:False Negative Reactions; D005260:Female; D006471:Gastrointestinal Hemorrhage / Q000175:diagnosis* / Q000209:etiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage* / Q000009:adverse effects; D012680:Sensitivity and Specificity; D013997:Time Factors; D055815:Young Adult
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D000925:Anticoagulants; D010975:Platelet Aggregation Inhibitors; D001241:Aspirin