Predicting Discontinuation of Pegylated Interferon as a Result of Lack of Efficacy in United States Veterans With Chronic Hepatitis C on Dual Therapy.

BACKGROUND: Many patients with chronic hepatitis C virus (HCV) being treated with pegylated interferon (peg-IFN) plus ribavirin (RBV) do not respond to therapy and do not clear the virus. Standard of care during the era of dual therapy was to discontinue the patient's therapy based on insufficient decreases in viral load after 12 and/or 24 weeks on therapy. OBJECTIVES: We identified patient characteristics that were significant predictors of discontinuation as a result of lack of efficacy (LOE) in a national database of US veterans with genotypes 1 and 4. METHODS: We identified US veterans who received care at Veterans Affairs medical centers in 2004-2009 and who had lab-confirmed HCV diagnoses and initiated therapy with peg-IFN plus RBV. Patients who discontinued therapy early were classified as either LOE or non-LOE discontinuers based on pharmacy refill patterns and laboratory response data. Predictors of LOE discontinuation were identified using univariate and multivariable Cox proportional hazards modeling. RESULTS: Of 321 238 HCV patients with an ICD-9 diagnosis code, 31 215 (9.7%) initiated dual therapy with peg-IFN plus RBV, and 10 333 (3.2%) met all inclusion criteria and were included in the analysis. Overall, 13.6% of the cohort was classified as LOE. Significant predictors of LOE discontinuation included treatment for drug abuse (hazard ratio [HR] = 2.18), age >65 years (HR = 1.75), antiretroviral therapy for HIV (HR = 1.48), black race (HR = 1.47), platelet count >100/mm3 (HR = 1.46), and drug therapy for insomnia (HR = 1.40). CONCLUSIONS: We identified risk factors for discontinuation caused by LOE. Future work should focus on determining whether these characteristics are also predictive of triple-therapy LOE discontinuations.

Adherence with bisphosphonate therapy in US veterans with rheumatoid arthritis.

OBJECTIVE: Pharmacy Benefits Management program data for patients enrolled in the Veterans Affairs Rheumatoid Arthritis (VARA) registry were linked with clinical data to determine bisphosphonate adherence and persistence among US veterans with rheumatoid arthritis (RA) and to determine factors associated with adherence. METHODS: The primary outcome measures were the duration of bisphosphonate therapy and the medication possession ratio (MPR). Patients with an MPR <0.80 were classified as nonadherent. Potential covariates considered in the analysis included patient demographics, RA disease activity and severity parameters, and factors associated with osteoporosis risk. Associations of patient factors with duration of therapy and adherence were examined using multivariable regression modeling. RESULTS: Bisphosphonates were prescribed to 573 (41.5%) of 1,382 VARA subjects. The mean ± SD duration of therapy for bisphosphonates was 39.2 ± 31.4 months. A longer duration of therapy correlated with older age, more years of education, and dual x-ray absorptiometry testing. The mean ± SD MPR of VARA subjects for bisphosphonate therapy was 0.69 ± 0.28; 302 (52.7%) were nonadherent. In multivariate analyses, nonadherence with bisphosphonate therapy was associated with a longer duration of RA disease (odds ratio [OR] 1.02, 95% confidence interval [95% CI] 1.00-1.04) and duration of bisphosphonate therapy >32 months (OR 1.63, 95% CI 1.04-2.57). Whites were less likely to have a low MPR compared with nonwhites (OR 0.52, 95% CI 0.30-0.88). CONCLUSION: Nonadherence with bisphosphonates was common in this cohort of RA patients and was associated with nonwhite ethnicity, a longer duration of RA disease, and a greater duration of bisphosphonate therapy.

Merging Veterans Affairs rheumatoid arthritis registry and pharmacy data to assess methotrexate adherence and disease activity in clinical practice.

OBJECTIVE: The Veterans Affairs (VA) Rheumatoid Arthritis (VARA) registry and the VA Pharmacy Benefits Management database were linked to determine the association of methotrexate (MTX) adherence with rheumatoid arthritis (RA) disease activity. METHODS: For each patient, the medication possession ratio (MPR) was calculated for the first episode of MTX exposure of a duration of ≥12 weeks for both new and established MTX users. High MTX adherence was defined as an MPR ≥0.80 and low MTX adherence was defined as an MPR <0.80. For each patient, the mean Disease Activity Score with 28 joints (DAS28) score, erythrocyte sedimentation rate (ESR), and C-reaction protein (CRP) level observed during registry followup were compared in high- versus low-adherence groups. RESULTS: In 455 RA patients, the prescribed doses of MTX (mean ± SD 16 ± 4 mg versus 16 ± 4 mg; P = 0.6) were similar in high-adherence patients (n = 370) in comparison to low-adherence patients (n = 85). However, the actual observed MTX doses taken by patients were significantly higher in the high-adherence group (mean ± SD 16 ± 5 mg versus 11 ± 3 mg; P < 0.001). DAS28 (mean ± SD 3.6 ± 1.2 versus 3.9 ± 1.5; P < 0.02), ESR (mean ± SD 24 ± 18 versus 29 ± 24 mm/hour; P = 0.05), and CRP level (mean ± SD 1.2 ± 1.3 versus 1.6 ± 1.5 mg/dl; P < 0.03) were lower in the high-adherence group compared to those with low MTX adherence. These variances were not explained by differences in baseline demographic features, concurrent treatments, or whether MTX was initiated before or after VARA enrollment. CONCLUSION: High MTX adherence was associated with improved clinical outcomes in RA patients treated with MTX. Adjustment for potential confounders did not alter the estimated effect of adherence. These results demonstrate the advantages of being able to merge clinical observations with pharmacy databases to evaluate antirheumatic drugs in clinical practice.