International variation in medication prescription rates among elderly patients with inflammatory bowel disease

Abstract

Background and aims: The elderly represent a growing demographic of patients with IBD. No study has previously described variations in care or medication prescriptions in senior patients with IBD. We compared prescription rates among elderly patients with IBD in four countries using health administrative data.

Methods: Databases from the United States (US), United Kingdom (UK), Denmark and Canada were queried. Variation in prescription rates between countries was assessed in patients ≥65y with prevalent IBD who had ≥1 prescription for an IBD-related medication in a given quarter between 2004 and 2009. Patients were identified using previously-reported, validated algorithms. Country-specific rates were compared in each quarter using Fisher's exact test.

Results: In patients with Crohn's disease, Canada and US had higher prescription rates for oral 5-ASA (P<0.0001 in all quarters) and infliximab (P<0.05 in 22/24 quarters), while the US had higher rates of thiopurine usage (P<0.05 in 23/24 quarters). Canada had greater rates of methotrexate prescriptions (P<0.05 in 21/24 quarters analyzed). In patients with ulcerative colitis (UC), rates of oral steroid usage was lowest in the US (P<0.05 in 22/24 quarters) and oral 5-ASA use was highest in the US and Canada (P<0.0001 in all quarters). Canada and Denmark used more rectal therapy than the US. Infliximab usage in UC was significantly higher in the US and Canada after 2006.

Conclusions: Significant variation in medication prescription rates exists among countries. Future research should assess whether these differences were associated with disparities in outcomes and health care costs.

Keywords: ASA; CD; Crohn's disease; DIN; Drug Identification Number; Drug prescriptions; GPRD; General Practice Research Database; Health administrative data; Health services research; IBD; Inflammatory bowel disease; MP; ODB; Ontario Drug Database; SASP; TR; Thompson Reuters; UC; UK; US; Ulcerative colitis; United Kingdom; United States; aminosalicylates; inflammatory bowel disease; mercaptopurine; sulfasalazine; ulcerative colitis.