Table 2.

Results with autofluorescence (AF) and methylene blue (MB) staining compared with histological findings as the reference standard in 345 biopsies from patients with Barrett’s osophagus (BO); the results of video endoscopy (VE) alone are also shown (with respect to the respective accuracy achieved, no statistically significant differences were found among the different methods used). A positive biopsy was from either a suspicious area on VE or any of the two methods tested (AF and MB), or from the additional four quadrant biopsies

Cancer	12	True positive*	3 (25%)	6 (50%)	8 (67%)
HGD	19	True positive*	5 (26%)	9 (47%)	8 (42%)
LGD	88	True positive*	11 (13%)	12 (14%)	14 (16%)
Normal BO	226	True negative†	206 (91%)	205 (91%)	214 (95%)

*Sensitivity of AF, MB, or VE in the detection of cancer, HGD, and LGD, respectively.

†Specificity of AF, MB, or VE in the correct recognition of normal BO (see text for positive and negative predictive values).

HGD, high grade dysplasia; LGD, low grade dysplasia.