DISCONTINUATION OF ORAL 5-AMINOSALICYLIC ACID THERAPY ASSOCIATED WITH INCREMENTAL ALL-CAUSE HEALTHCARE COSTS IN ACTIVE ULCERATIVE COLITIS PATIENTS

Purpose:  To assess the association between oral 5-aminosalicylic acid (5-ASA) treatment discontinuation and all-cause healthcare costs in patients with active ulcerative colitis (UC).

Method:   IMS LifeLink™ Health Plan claims data 2007-2011 were analyzed to identify UC patients aged ≥18 years with ≥1 UC diagnosis (ICD-9-CM: 556.x) and had ≥1 prescription for oral 5-ASA during the study period.  Patients with active disease were identified as those who had ≥1 prescription for corticosteroid and ≥2 UC-specific medical claims during 12 months post initiation of 5-ASA (index date).  Eligible patients were followed up for 12 months post index date to measure treatment discontinuation and healthcare costs.  Discontinuation of 5-ASA treatment was defined if patients had ≥60 days without prescription fills and neither switched to other non-index drug, nor restarted index medication.  We calculated all-cause healthcare costs including prescription, emergency room (ER) visits, inpatient hospitalizations, and other medical claims.  Multivariable generalized linear models with a log-link function and a gamma distribution were used to investigate the association of treatment discontinuation and healthcare costs. 

Result:   Of 1,855 patients who were identified as having active UC disease, 607 (32%) patients discontinued oral 5-ASA treatment.  Mean age was 46.6±15.7 years, and 51% were female.  When compared to patients without discontinuing 5-ASA treatment, patients who discontinued were associated with decreased mean (standard error) all-cause prescription costs of $1,992 ($193, P=0.000), but increased ER costs of $72 ($27, P=0.007), hospitalization costs of $3,026 ($953, P=0.001), other medical claims costs of $1,711 ($623, P=0.006), and total healthcare costs of $2,894 ($1,328, P=0.03) even with the adjustment for patients’ social demographic characteristics, health insurance status, number of comorbidities, residing region, access to specialist care, use of immunosuppressive/biologic agents, and use of rectal form of 5-ASA. 

Conclusion:   Discontinuation of oral 5-ASA treatment in the active UC patients was associated with significantly increased all-cause healthcare costs, especially the costs of hospitalization.  At the margin, increased spending on medical claims significantly exceeded the costs of the drug for the patients who discontinued treatment.