Wednesday, October 22, 2014
Poster Board # PS4-51

Jennifer Cooper, MPH1, Brian Bartle, MPH2, Min-Woong Sohn, PhD2, Gary Chan, PhD3, Vishal Ahuja, PhD4, Anirban Basu, PhD3 and Elbert S. Huang, MD, MPH1, (1)University of Chicago, Chicago, IL, (2)Center for Management of Complex Chronic Care, Hines, IL, (3)Department of Health Services, University of Washington, Seattle, Seattle, WA, (4)Center on Aging at NORC, University of Chicago, Chicago, IL
Purpose: Clinical trials of intensive glucose lowering have raised questions about the potential harms of longitudinal treatment patterns that utilize complex drug combinations or have frequent changes.  In a real-world patient population, very little is known about what treatment patterns are used over time.        

Method: We created a national diabetes cohort using data from the Department of Veteran Affairs and Medicare.  Patients were included if they had ≥2 diagnostic codes conferring a positive diagnosis of type 2 diabetes, and age ≥40 years as of 1/1/2003.  We further limited the cohort to metformin monotherapy users (≥90 day supply of metformin dispensed during CY 2002 with no history of other pharmacologic intervention for diabetes).  Medication patterns were assessed from 1/1/2003 to 12/31/2011.  Patients were followed until leaving the cohort (death) or the end of the study.  Glucose-lowering drugs were categorized into 11 classes and dosing was ignored.  A patient was considered a user if they were dispensed ≥30 day supply at any point during the study period.  Drug episodes (discontinuation, restart, intensification and switching) and individual medication patterns were examined.


   Our cohort consisted of 76,216 veterans, who were majority male (98%), Caucasian (84%), and elderly (average age 66).  Thirty-five percent of the cohort died during the study period.  The average number of drugs prescribed per patient during the 9-year follow-up was 2.6 ± 1.4.  While most patients took a total of ≤2 different drugs over the 9 years, 11% took ≥5, with a very small percentage taking up to 9 different drugs.  Nearly 23% of the cohort maintained a metformin-only treatment pattern.  Within this group, 8% consistently used metformin, 83% had intermittent use (discontinuation and restart), and 9% discontinued metformin all together without switching to another drug.  The first drug episode of the remaining population was either a switch to another medication (15%), movement to dual-therapy (metformin plus another drug; 55%), or movement to triple-therapy and beyond (metformin plus ≥2 more drugs; 6%).  Sulfonylurea was the most common drug a patient was either switched to or intensified with. Overall, there were 27,760 unique longitudinal treatment patterns. 

Conclusion: There is extreme variability in medications that are prescribed in real clinical practice.  These patterns will be assessed in relation to diabetes-related complications.