Although the Geboes score (GS) and modified Riley score (MRS) are commonly used to evaluate histological disease activity in ulcerative colitis, their operating properties are unknown.
Accordingly, Dr Barrett Levesque and Canada developed an alternative instrument.
The team reported that 4 pathologists scored 48 ulcerative colitis colon biopsies using the GS, MRS and a visual analogue scale global rating.
Intra-rater and inter-rater reliability for each index and individual index items were measured using intraclass correlation coefficients.
The researchers used that items with high reliability developed the Robarts histopathology index.
|The correlation estimate between change scores in Robarts histopathology index and change score in GS was 0.75 |
The responsiveness/validity of the Robarts histopathology index and multiple histological, endoscopic and clinical outcome measures were evaluated by analyses of change scores, standardized effect size and Guyatt's responsiveness statistic using data from a clinical trial of an effective therapy.
Inter-rater intraclass correlation coefficients for the total GS and MRS scores were 0.79, and 0.80.
The correlation estimates between change scores in Robarts histopathology index and change score in GS and MRS were 0.75 and 0.84, respectively.
The research team found that the standardized effect size and Guyatt's responsiveness statistic estimates for GS, MRS and Robarts histopathology index were: 1.87 and 1.23, 1.29 and 0.88, and 1.05 and 0.88, respectively.
Dr Levesque's team concludes, "The Robarts histopathology index is a new histopathological index with favorable operating properties."