Original article—alimentary tract
Correlation Between the Crohn's Disease Activity and Harvey–Bradshaw Indices in Assessing Crohn's Disease Severity

https://doi.org/10.1016/j.cgh.2010.01.001Get rights and content

Background & Aims

Clinical trials of Crohn's disease generally use the Crohn's Disease Activity Index to assess disease activity; these calculations are complex, time-consuming, and impracticable. We investigated whether a simpler tool, the Harvey–Bradshaw Index, was equally effective in assessing disease severity.

Methods

Crohn's Disease Activity and Harvey-Bradshaw Index scores were collected from 2 large multicenter Crohn's disease studies. The PEGylated antibody fragment evaluation in Crohn's disease: safety and efficacy (PRECiSE) 1 and 2 trials assessed efficacy and tolerability of certolizumab pegol (PEGylated, humanized, Fab' fragment of an antitumor necrosis factor α antibody). PRECiSE 1 and 2 data were analyzed to determine if results from the Crohn's Disease Activity Index correlated with those from the Harvey-Bradshaw Index criteria for defining response and remission.

Results

Analysis of almost 1000 data pairs showed a positive correlation between scores. The correlation between the indices for pooled data from PRECiSE 1 and PRECiSE 2 was 0.800 (Spearman correlation coefficient). The correlations between indices for the PRECiSE 1 or PRECiSE 2 were 20.698 and 0.716, respectively (Kronecker product variance). A 3-point change in the Harvey-Bradshaw Index score corresponded to a 100-point change in the Crohn's Disease Activity Index (clinical response); scores ≤4 points corresponded to a Crohn's Disease Activity Index score ≤150 points (clinical remission).

Conclusions

Results from the Crohn's Disease Activity Index correlate with those from the Harvey-Bradshaw Index; use of the Harvey-Bradshaw Index might permit simpler Crohn's disease activity assessment in long-term clinical trials, and facilitate standardized disease activity measurements and cross-center comparisons.

Section snippets

Patients

Patients enrolled in PRECiSE 1 and PRECiSE 2 were aged ≥18 years and had moderate to severe active Crohn's disease (defined as a CDAI score of 220–450 points). To be eligible for enrollment, patients had to have been diagnosed with Crohn's disease at least 3 months before screening, based on radiologic, endoscopic, or histologic evidence. The protocals were approved by the institutional review board or ethics committee at each center. All patients gave written informed consent.

Study Procedures

In PRECiSE 1, 660

Correlation Between the CDAI and HBI

In the 2 studies, values for HBI ranged from 0 to 33, and CDAI values ranged from –16 to 661.7. In total, pairs of observations were available for 995 patients for the overall comparison of CDAI versus HBI scores, and 989 pairs of observations were available for the analysis of change from baseline in CDAI and HBI. The maximum number of patients for which paired data would have been available would have been 1088 as 240 patients in the PRECiSE 2 study did not respond to induction therapy and so

Discussion

These data from 1328 patients in the PRECiSE 1 and PRECiSE 2 studies represent by far the largest comparison and cross-validation of the HBI and CDAI published to date. The findings show that a decrease in CDAI score of 100 points corresponds with a decrease in HBI of 3.20 points, which is equivalent to a change of 31.25 points on the CDAI for 1 point on the HBI.

The findings of this analysis are in close agreement with the results from a previous comparison of these scales, which found a

Acknowledgments

Editorial assistance was provided by Dave Burton at Adelphi Communications Ltd, Cheshire, UK; and Lisa Thomas, at PAREXEL MMS, Worthing, UK, with funding from UCB Pharma, Brussels, Belgium.

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    Conflicts of interest The authors disclose the following: William J. Sandborn received research support and consultant fees from UCB Pharma; Paul Rutgeerts received lecture fees, consultant fees, and research support from UCB Pharma. The remaining authors disclose no conflicts.

    Funding The development of this manuscript was funded by UCB Pharma, Brussels, Belgium.

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