Introduction: Population-based studies have identified significant differences in drug prescription practices in inflammatory bowel disease (IBD) among different age groups. This study aimed to offer insight from an IBD population in the United States.
Methods: In this retrospective chart review, Veterans with diagnostic codes for Crohn's Disease (CD: ICD-9-CM 555.x and ICD-10-CM K50.x) and ulcerative colitis (UC: ICD-9-CM 556.x and ICD-10-CM K51.x) first recorded between 01/2013 to 08/2016 at the Cleveland VAMC were included. Based on the age at the time when the IBD diagnostic code was first assigned, the patients were categorized into the younger (age < 65) or older (age ≥ 65) cohorts. Patients' complete drug dispensing history from our institution, including medications dispensed prior to the diagnosis of IBD, were compared among the two age groups. Agents include 5-aminosalicylic acid (5-ASA), budesonide (BUD), azathioprine/6-mercaptopurine (AZA/6-MP), methotrexate (MTX), infliximab (IFX), adalimumab (ADA), certolizumab (CTZ), and vedolizumab (VEDO). The highest dose of corticosteroids (CS) was categorized into high (prednisone >10 mg for ≥4 weeks) or low (prednisone ≤10 mg for any duration or ≥10 mg for < 4 weeks) dose.
Results: In this cohort of 571 Veterans with IBD, the median age was 64 (range 21-93) and 527 (93%) were men. The younger group consisted of 298 Veterans with 115 (39%) CD and 183 (61%) UC. The older group consisted of 273 with 71 (26%) CD and 202 (74%) UC. Comparing the younger and older cohorts respectively, 5% vs 4% had sulfasalazine, 31% vs 29% 5-ASA, 9% vs 11% BUD, 8% vs 3% AZA/6-MP (P=0.024), 3% vs 2% IFX, 5% vs 2% ADA (P=0.029), 1% vs none VEDO, 10% vs 5% high dose CS (P=0.021), 26% vs 21% low dose CS. Neither MTX or CTZ was prescribed. There were statistically significant differences in the use of AZA/6-MP, ADA, and high dose CS. No statistical difference was seen in the use 5-ASA, or other immunomodulators or biologics among the two cohorts.
Conclusion: Overall, the use of immunosuppressives and biological therapy in this cohort was lower compared to non-veterans populations. Older IBD patients who were ≥ 65 years old were less likely to receive AZA/6-MP, ADA, or high dose CS. Further research is needed to determine whether this discrepancy is related to providers' concerns for potential medication-associated adverse effects, patients' values and preferences, or tendency for older patients to present with milder disease.