Sa1233 Early Diagnosis of Crohn's Disease (CD) Is Associated With Lesser Complications

Abstract

between OC use and risk of CD complications using a large population-based cohort. Methods: We conducted a prospective study of female CD patients identified from the inpatient and outpatient care components of the Swedish National Patient Register from 2002 to 2009 with follow up through December of 2012. Potential CD cases were eligible if they had at least two encounters in the hospital or outpatient clinics with primary or secondary diagnosis of CD (ICD9 = ‘555' and ICD10 = ‘K50'). Information on OC use was obtained from the Prescribed Drug Register starting in July of 2005 and updated until December of 2012. Primary outcome was defined as first CD-related surgery identified through surgical procedure codes from the National Patient Register. We used Cox proportional hazard modeling with time-varying covariates to estimate multivariable-adjusted hazard ratio (MV-adjusted HR) and 95% confidence interval (CI) while adjusting for age, duration of disease, number of encounters, education, and county of residence. Results: Among 6,788 incident cases of CD, we documented 200 cases of CD-related surgery over 50,400 person-years of follow up. Compared to non-users, current and past use of OC were not associated with risk of CD-related surgery (MV-adjusted HR = 0.89, 95% CI 0.54-1.47 and 0.61, 95% CI 0.33-1.31, respectively). The association did not appear to be modified by longer duration of use. Compared to non-users of OC, the MV-adjusted HRs of surgery were 0.63 (95% CI, 0.38-1.05) for less than two years of use, and 1.28 (95% CI, 0.632.60) for two or more years of use. In sensitivity analyses, we limited our cohort to participants with age of CD diagnosis less than or equal to 40 and obtained similar results: Compared to non-users of OC, the MV-adjusted HRs of surgery were 0.87 (95% CI, 0.51-1.47) for current users of OC and 0.63 (0.33-1.17) for past users of OC. Finally, we considered the possibility that prescribing OC maybe more common among patients with more severe disease and therefore performed lag analysis using prescription data from six months prior to each one-month follow up. Similar to our main analysis, there was no statistically significant association between OC use and risk of surgery among CD patients (MV-adjusted HR = 0.70, 95% CI 0.37-1.33 for past OC use and 0.87, 95% CI 0.51-1.47 for current OC use). Conclusions: In a large nationwide registry of CD patients, we did not detect an association between OC use and CD-related surgery.