Utilization of health-care resources by patients with IBD in Manitoba: a profile of time since diagnosis.

OBJECTIVES: We tested the hypothesis of nonlinear longitudinal trends in health-care utilization by individuals with Crohn's disease (CD) and ulcerative colitis (UC) in Manitoba.
METHODS: Administrative databases were used to report resource use in 2000/1. A total of 5,485 cases of CD and UC and 45,279 matched controls were separated into incident cases (0-2 yr of disease), cases with longstanding disease (3-10 yr), and cases with very longstanding disease (>10 yr). Relative risk ratios (RRR) indicating the likelihood of resource use, given disease duration, were computed using multinomial logistic regression analysis. Sensitivity analysis was conducted to test the robustness of results to altering the disease duration cutoffs.
RESULTS: Independent of disease duration, in general, outpatient utilization was over twice as likely among IBD cases compared with controls whether or not the contact was made for IBD-specific reasons. The likelihood of utilization was greatest among incident cases for outpatient visits with an internist (RRR 6.16, 95% CI 5.11-7.43) and surgical visits (RRR 3.78, 95% CI 3.14-4.55). Inpatient stays for IBD-specific reasons in general were considered dependent on disease duration; in particular, there was a fourfold higher likelihood for the incident cases relative to their controls. For non-IBD-specific reasons, IBD cases were 1.5 times as likely to have inpatient stays, regardless of disease duration.
CONCLUSIONS: Our results suggest that within the first 2 yr from disease diagnosis the most costly resources were employed. We can likely measure the greatest proportion of treatment effects on resource use within a relatively short period.