BACKGROUND: Although the Medicare Part D coverage gap phase-out should reduce cost-related nonadherence (CRN) among seniors with diabetes, preferential generic prescribing may have already decreased CRN, while smaller numbers of patients using more costly branded oral anti-diabetic (OAD) medications remain vulnerable to CRN. OBJECTIVE: To estimate the effects of cost sharing in the Part D standard (non-LIS) benefit on adherence to different OAD classes, comparing two classes dominated by inexpensive generic medications and two by more costly branded medications. DESIGN AND PATIENTS: Retrospective cohort study using dispensed prescription data for elderly non-LIS (N=81,047) and LIS (low-income subsidy) (N=150,359) beneficiaries using same class OAD(s) in 2008 and 2009. Logistic regression modeled non-LIS likelihood; LIS and non-LIS patients matched using propensity outcome (N=38,054). Logistic regression, controlling for demographic and health status characteristics, modeled effects of non-LIS coverage on 2009 OAD class adherence. MAIN MEASURES: Main outcome measures were within-class OAD coverage year adherence, with patients considered adherent when days supplied to calendar days ratio at least 0.8. KEY RESULTS: Non-LIS patients had 0.52 and 0.57 times the odds of branded-only DPP-4 Inhibitor (N=1,812; 95 % CI: 0.43, 0.63; P<0.001) and Thiazolidinedione (TZD) (N=6,290; 95 % CI: 0.52, 0.63; P<0.001) adherence. Most patients (N=32,510; 82 %) used OADs in primarily generic classes, where we found no significant (Biguanides; N=21,377) or small differences (Sulfonylureas/Glinides [N=19,240; OR: 0.91; 95 % CI: 0.86, 0.97; P=0.002]) in adherence odds. Crude adherence rates were sub-optimal when CRN was not a factor (Non-LIS/LIS: Biguanides: 65 %/65 %; Sulfonylureas/Glinides: 66 %/68 %; LIS: DPP-4 Inhibitors: 66 %; TZDs: 67 %). CONCLUSIONS: Gap elimination would not affect generic, but should reduce branded OAD CRN. Branded copayments may continue to lead to CRN. Policy initiatives and benefit changes targeting both cost deterrents for patients with more complex disease and non-cost generic OAD underuse are recommended.
BACKGROUND: Although the Medicare Part D coverage gap phase-out should reduce cost-related nonadherence (CRN) among seniors with diabetes, preferential generic prescribing may have already decreased CRN, while smaller numbers of patients using more costly branded oral anti-diabetic (OAD) medications remain vulnerable to CRN. OBJECTIVE: To estimate the effects of cost sharing in the Part D standard (non-LIS) benefit on adherence to different OAD classes, comparing two classes dominated by inexpensive generic medications and two by more costly branded medications. DESIGN AND PATIENTS: Retrospective cohort study using dispensed prescription data for elderly non-LIS (N=81,047) and LIS (low-income subsidy) (N=150,359) beneficiaries using same class OAD(s) in 2008 and 2009. Logistic regression modeled non-LIS likelihood; LIS and non-LISpatients matched using propensity outcome (N=38,054). Logistic regression, controlling for demographic and health status characteristics, modeled effects of non-LIS coverage on 2009 OAD class adherence. MAIN MEASURES: Main outcome measures were within-class OAD coverage year adherence, with patients considered adherent when days supplied to calendar days ratio at least 0.8. KEY RESULTS: Non-LISpatients had 0.52 and 0.57 times the odds of branded-only DPP-4 Inhibitor (N=1,812; 95 % CI: 0.43, 0.63; P<0.001) and Thiazolidinedione (TZD) (N=6,290; 95 % CI: 0.52, 0.63; P<0.001) adherence. Most patients (N=32,510; 82 %) used OADs in primarily generic classes, where we found no significant (Biguanides; N=21,377) or small differences (Sulfonylureas/Glinides [N=19,240; OR: 0.91; 95 % CI: 0.86, 0.97; P=0.002]) in adherence odds. Crude adherence rates were sub-optimal when CRN was not a factor (Non-LIS/LIS: Biguanides: 65 %/65 %; Sulfonylureas/Glinides: 66 %/68 %; LIS: DPP-4 Inhibitors: 66 %; TZDs: 67 %). CONCLUSIONS: Gap elimination would not affect generic, but should reduce branded OAD CRN. Branded copayments may continue to lead to CRN. Policy initiatives and benefit changes targeting both cost deterrents for patients with more complex disease and non-cost generic OAD underuse are recommended.
Authors: Kevin L Sloan; Anne E Sales; Chuan-Fen Liu; Paul Fishman; Paul Nichol; Norman T Suzuki; Nancy D Sharp Journal: Med Care Date: 2003-06 Impact factor: 2.983
Authors: Haiden A Huskamp; Patricia A Deverka; Arnold M Epstein; Robert S Epstein; Kimberly A McGuigan; Richard G Frank Journal: N Engl J Med Date: 2003-12-04 Impact factor: 91.245
Authors: Dana P Goldman; Geoffrey F Joyce; Jose J Escarce; Jennifer E Pace; Matthew D Solomon; Marianne Laouri; Pamela B Landsman; Steven M Teutsch Journal: JAMA Date: 2004-05-19 Impact factor: 56.272
Authors: Rajesh Balkrishnan; Rukmini Rajagopalan; Fabian T Camacho; Sally A Huston; Frederick T Murray; Roger T Anderson Journal: Clin Ther Date: 2003-11 Impact factor: 3.393
Authors: Lidia Mvr Moura; Eli L Schwamm; Valdery Moura Junior; Michael P Seitz; Daniel B Hoch; John Hsu; Lee H Schwamm Journal: Clinicoecon Outcomes Res Date: 2016-11-17