Linking Crohn's disease health status measurements with International Classification of Functioning, Disability and Health and vocational rehabilitation outcomes.

OBJECTIVE The International Classification of Functioning, Disability and Health (ICF) serves as a unifying model for rehabilitation medicine. Variables of the health status measurements, the Crohn's Disease Activity Index and the Harvey-Bradshaw Index, have not been linked with the ICF categories and compared with other predictors of rehabilitation outcomes. METHODS Crohn's Disease Activity Index variables were linked with ICF categories using linking rules. A chart review included the patients of our in-patient rehabilitation centre during one year (n=355) with International Classification of Disease Codes for Crohn's disease (ICD K50). We identified variables linked with clinical improvement (decrease in the Harvey-Bradshaw Index of > or = 2 U) and rehabilitation success (conversion from unfit-to-work to fit-to-work) by multivariate logistic regression. RESULTS The ICF component, activities and participation, was not represented in the Crohn's Disease Activity Index and the Harvey-Bradshaw Index. A Harvey-Bradshaw Index > or = 5 U was associated with clinical improvement during rehabilitation (odds ratio 5.65 (95% CI 3.41-9.35)). Normal C-reactive protein (odds ratio 2.8 (95% CI 1.1-7.0)) and higher body mass index (odds ratio (per 1 kg/m2 increase) 1.1 (95% CI 1.0-1.2)), but not Harvey-Bradshaw Index, were associated with vocational rehabilitation success in 124 patients who were initially unfit-to-work. CONCLUSION Variables representing activities and participation as well as immune functions may improve Crohn's disease health status measurements on the basis of better prediction of vocational rehabilitation success.