Table 1

Number* and percentage (in parenthesis) of patients with Crohn’s disease and ulcerative colitis (UC) correctly diagnosed by 13 experts and 12 non-experts on the rectal biopsies and full series in rounds 1 and 2

Crohn’s diseaseUC
ExpertsNon-expertsExpertsNon-experts
*Although there were 19 cases of CD and 24 of UC, not all cases were viewed by all pathologists; missing values are shown in square brackets. The results are presented as a percentage of the total diagnoses available for each category. If all cases had been viewed, for CD n=247 (experts) and 228 (non-experts). If all UC cases had been viewed n=312 (experts) and 288 (non-experts).
Round 1
    Rectal39 (17) [18]31 (14) [10]190 (65) [21]170 (62) [15]
    Overall70 (16)360 (64)
    Full series130 (56) [15]109 (50) [10]213 (74) [24]195 (72) [16]
    Overall239 (53)408 (73)
Round 2
    Rectal58 (24) [8]26 (12) [7]195 (66) [15]170 (62) [14]
    Overall84 (18)365 (64)
    Full series152 (64) [9]131 (60) [10]212 (73) [22]203 (76) [20]
    Overall283(62)415 (74)