Acceptability and accuracy of a non-endoscopic screening test for Barrett's oesophagus in primary care: cohort study

Abstract

Objectives: To determine the accuracy and acceptability to patients of non-endoscopic screening for Barrett's oesophagus, using an ingestible oesophageal sampling device (Cytosponge) coupled with immunocytochemisty for trefoil factor 3.

Design: Prospective cohort study.

Setting: 12 UK general practices, with gastroscopies carried out in one hospital endoscopy unit.

Participants: 504 of 2696 eligible patients (18.7%) aged 50 to 70 years with a previous prescription for an acid suppressant (H(2) receptor antagonist or proton pump inhibitor) for more than three months in the past five years.

Main outcome measures: Sensitivity and specificity estimates for detecting Barrett's oesophagus compared with gastroscopy as the ideal method, and patient anxiety (short form Spielberger state trait anxiety inventory, impact of events scale) and acceptability (visual analogue scale) of the test.

Results: 501 of 504 (99%) participants (median age 62, male to female ratio 1:1.2) successfully swallowed the Cytosponge. No serious adverse events occurred. In total, 3.0% (15/501) had an endoscopic diagnosis of Barrett's oesophagus (≥1 cm circumferential length, median circumferential and maximal length of 2 cm and 5 cm, respectively) with intestinal metaplasia. Compared with gastroscopy the sensitivity and specificity of the test was 73.3% (95% confidence interval 44.9% to 92.2%) and 93.8% (91.3% to 95.8%) for 1 cm or more circumferential length and 90.0% (55.5% to 99.7%) and 93.5% (90.9% to 95.5%) for clinically relevant segments of 2 cm or more. Most participants (355/496, 82%, 95% confidence interval 78.9% to 85.1%) reported low levels of anxiety before the test, and scores remained within normal limits at follow-up. Less than 4.5% (2.8% to 6.1%) of participants reported psychological distress a week after the procedure.

Conclusions: The performance of the Cytosponge test was promising and the procedure was well tolerated. These data bring screening for Barrett's oesophagus into the realm of possibility. Further evaluation is recommended.

Fig 1 Cytosponge in gelatine capsule (right) and expanded (left)

Fig 2 Flow of patients through trial

Fig 3 Endoscopic view of a patient with C2M4 segment length Barrett’s oesophagus (panel A). Haematoxylin and eosin (panel B ×100, panel C ×400) and trefoil factor 3 (panel D ×100, panel E ×400) staining from representative patient with Barrett’s oesophagus

Fig 4 Participants’ experience, anxiety, and distress related to Cytosponge test. Anxiety measured at day 0, 7, and 90 using six item short form short form Spielberger state trait anxiety inventory (values >40 denote clinically significant anxiety). Distress associated with Cytosponge test measured using impact of events scale. Intrusion and avoidance scores >19 denote high impact of test and >38 for total score. Participants rated their experience of Cytosponge using a visual analogue scale, with 0 representing the “worst experience” and 10 the “best experience”