TABLE 3.

Multivariate Cox Proportional Hazards Analysis With Backward Covariate Selection for Clinical Factors Associated with Composite Effectiveness^a

Covariatesb	Hazard Ratio	95% Confidence Interval	P
Adult-onset IBDc	0.846	0.575–1.245	0.40
>1 Comorbidity at Entry	1.320	0.918–1.898	0.13
Prior Hospitalization	1.426	0.895–2.270	0.14
Clinical Flare at Cohort Entry	1.520	1.037–2.228	0.03
Medication at Cohort Entryd	1.378	0.948 0 2.004	0.09
Corticosteroids at Cohort Entry	1.621	1.048–2.509	0.03
Prior GI Surgery	1.396	0.910–2.141	0.13

^aComposite effectiveness defined as the first occurrence of IBD-related surgery, hospitalization, treatment escalation, clinical flare, or disease complication following cohort entry. Treatment escalation defined as any change to higher class of medication; increases in dosage/frequency; or changes within a class of medications. Disease complication defined as any new stricture, fistula, or perianal behavior.

^bCovariates were selected via backward regression with p-cutoff of 0.2.

^cAdult-onset IBD defined as age of IBD diagnosis younger than 60 years, compared with elderly-onset IBD (60 years and older at diagnosis) as baseline.

^dMedication at cohort entry defined as a binary categorical variable: either taking no medications/5-aminosalicylates at entry (baseline) or taking immunomodulators/biologics at entry.

Abbreviations: IBD, inflammatory bowel diseases; GI, gastrointestinal