Analyses
The effectiveness of case management will be established in multivariate multilevel analyses, according to the intention-to-treat principle. When possible, specific attention will be paid to identify subgroups of patients characterized by their profile of comorbidity in which the intervention is more effective than in other subgroups. The data might allow calculating an individual case management exposure level score, in the intervention group as well as in the control group. This will enable analyses of the outcome measures according to the per-protocol principle. Differences between patients exposed to the case management program and patients in the control condition on patient's health care utility and patient's health status will be tested using a chi-square test and student t-test, respectively. Potential confounding is checked, including the effect of different case managers and the number of patients per case manager.