Consistent with hypothesis #1, beneficiaries facing the lowest cost sharing (FBDE) had the highest mean days supply of all OHAs combined (452 days) and the group facing the highest cost sharing (non-LIS) had the fewest days supply (432), but the difference was a mere 4.6 percent.
The number of generic fills was 11 percent higher among FBDE recipients compared to non-LIS beneficiaries (8.7 vs.
$13.90 for generics by FBDE and non-FB recipients, respectively, and $147.14 vs.
The overall cost of OHA therapy for non-LIS beneficiaries was 28 percent below that of FBDE recipients ($656.29 vs.
For example, the unadjusted difference in annual brand days supply between FBDE and non-FB recipients of 15 days (already a small difference) was reduced to 7 days after adjustment.
In adjusted analyses, mean annual OHA days supply differed by less than 2.5 percent between FBDE and non-LIS beneficiaries.
During our study year, the effective 30-day copay for non-FB recipients ($3.93) was almost twice that of FBDE recipients ($2.12), but the adjusted differences in GDR and annual OHA cost were just 1 percentage point and $35, respectively.
Diabetes severity and comorbidity measures were highest for FBDE recipients and lowest for non-LIS beneficiaries.
To give just one example, the statutory brand copay for FBDE recipients in 2008 was $3.10, whereas the effective copay per 30-day supply was just $2.12, due to larger fill sizes.