Cost-Effectiveness of Dipeptidylpeptidase-4 Inhibitors Added to Metformin in Patients With Type 2 Diabetes in China.

Purpose: Dipeptidylpeptidase-4 (DPP-4) inhibitors, including linagliptin, alogliptin, saxagliptin, sitagliptin, and vildagliptin, are used for the treatment of type 2 diabetes mellitus (T2DM) patients in China. This study assessed the economic outcomes of different DPP-4 inhibitors in patients with T2DM inadequately controlled with metformin in the Chinese context. Materials and Methods: In this study, the validated Chinese Outcomes Model for T2DM (COMT) was conducted to project economic outcomes from the perspective of Chinese healthcare service providers. Efficacy and safety, medical expenditure, and utility data were derived from the literature, which were assigned to model variables. The primary outputs of the model included the lifetime costs, quality-adjusted life years (QALYs), and incremental cost-effectiveness ratio (ICER). One-way and probability sensitivity analysis was conducted to assess the potential uncertainties of parameters. Results: Of the five competing strategies, alogliptin 25 mg strategy yielded the most significant health outcome, which associated with improvements in discounted QALY of 0.007, 0.014, 0.011, and 0.022 versus linagliptin 5 mg, saxagliptin 5 mg, sitagliptin 100 mg and vildagliptin50 mg, respectively. The sitagliptin 100 mg strategy was the cheapest option. The ICER of alogliptin 25 mg against sitagliptin 100 mg strategy was $6,952 per additional QALY gained, and the rest of the strategies were dominated or extended dominated. The most influential parameters were the cost of DPP-4 inhibitors and their treatment efficacy. Conclusions: These results suggested that alogliptin was a preferred treatment option compared with other DPP-4 inhibitors for Chinese patients whose T2DM are inadequately controlled on metformin monotherapy.

Concordance with prescribing information dosage recommendations for dipeptidyl-peptidase-4 inhibitors among type 2 diabetes mellitus patients with moderate to severe chronic kidney disease.

OBJECTIVE: To estimate the proportion of patients with moderate to severe chronic kidney disease (CKD) whose initial dipeptidyl-peptidase-4 inhibitor (DPP4-i) dosage was concordant with prescribing information (label) recommendations in the United States. METHODS: Adult patients with type 2 diabetes mellitus (T2DM) who initiated a DPP4-i (linagliptin, sitagliptin, saxagliptin) between 1 January 2011 and 30 June 2014 were identified using electronic medical records and administrative claims, with index date being the date of first observed DPP4-i treatment. Patients were required to have chronic kidney disease (CKD) stage 3b, 4 or 5 (estimated Glomerular Filtration Rate [eGFR] value <45 ml/min/1.73 m2) during the 12 month pre-index period. Patients were classified as concordant or not concordant based on whether the first prescribed dose was consistent with label recommendations. Demographics, clinical characteristics, resource use and costs during pre-index were evaluated by DPP4-i concordance status. RESULTS: Of the 492 patients (323 sitagliptin, 57 saxagliptin, 112 linagliptin), 36.2% were prescribed doses that were not concordant with label recommendations (44.9% for sitagliptin, 57.9% for saxagliptin and 0% for linagliptin [which does not require dosage adjustment]). Concordant patients were slightly older (mean age 71 years vs. 68, p = .01) but had similar gender distribution (55% vs. 60% female, p = .31) compared to those who were not concordant. They had lower general health status (Charlson Comorbidity Score 2.6 vs. 2.2, p = .03), and had similar pre-index all-cause total costs ($25,245 vs. $21,972, p = .68) and lower pre-index T2DM-related costs ($1618 vs. $1922, p = .05). CONCLUSIONS: More than a third of DPP4-i patients with CKD stage 3b or higher were prescribed doses not concordant with DPP4-i label dosage recommendations.

Healthcare costs among adults with type 2 diabetes initiating saxagliptin or linagliptin: a US-based claims analysis.

OBJECTIVE: To compare healthcare costs of adults with type 2 diabetes (T2D) after initiation of saxagliptin or linagliptin, two antidiabetic medications in the dipeptidyl peptidase-4 inhibitor medication class. METHODS: Patients with T2D who were at least 18 years old and initiated saxagliptin or linagliptin (index date) between 1 June 2011 and 30 June 2014 were identified in the MarketScan Commercial and Medicare Supplemental Databases. All-cause healthcare costs and diabetes-related costs (T2D diagnosis on a medical claim and/or an antidiabetic medication claim) were measured in the 1 year follow-up period. Saxagliptin and linagliptin initiators were matched using propensity score methods. Cost ratios (CRs) and predicted costs were estimated from generalized linear models and recycled predictions. RESULTS: There were 34,560 saxagliptin initiators and 18,175 linagliptin initiators identified (mean ages 57 and 59; 55% and 56% male, respectively). Before matching, saxagliptin initiators had significantly lower all-cause total healthcare costs than linagliptin initiators (mean = $15,335 [SD $28,923] vs. mean = $20,069 [SD $48,541], p < .001) and significantly lower diabetes-related total healthcare costs (mean = $6109 [SD $13,851] vs. mean = $7393 [SD $26,041], p < .001). In matched analyses (n = 16,069 per cohort), saxagliptin initiators had lower all-cause follow-up costs than linagliptin initiators (CR = 0.953, 95% CI = 0.932-0.974, p < .001; predicted costs = $17,211 vs. $18,068). There was no significant difference in diabetes-related total costs after matching; however, diabetes-related medical costs were significantly lower for saxagliptin initiators (CR = 0.959, 95% CI = 0.927-0.993, p = 0.017; predicted costs = $3989 vs. $4159). CONCLUSIONS: Adult patients with T2D initiating treatment with saxagliptin had lower total all-cause healthcare costs and diabetes-related medical costs over 1 year compared with patients initiating treatment with linagliptin.

Adherence, Persistence, and Health Care Costs for Patients Receiving Dipeptidyl Peptidase-4 Inhibitors.

BACKGROUND: The dipeptidyl peptidase-4 (DPP-4) inhibitors are among the newer, yet more established, classes of diabetes medications. OBJECTIVE: To compare adherence, persistence, and health care costs among patients taking DPP-4 inhibitors. METHODS: Claims were extracted from Humana Medicare Advantage Prescription Drug (MAPD) or commercial plans for patients aged > 18 years with ≥ 1 prescription filled for a DPP-4 inhibitor between July 1, 2011, and March 31, 2013. The first prescription claim for a DPP-4 inhibitor established the index date and index medication; 12-month pre-index and post-index data were analyzed. The Diabetes Complications Severity Index (DCSI) was used to assess a level of baseline diabetes-related comorbidities. Adherence (proportion of days covered [PDC] ≥ 80%) and persistence (< 31-day gap) measures were compared before and after, adjusting for DCSI, pre-index insulin, age, and gender. Post-index costs (in 2013 U.S. dollars) were compared using general linear modeling (GLM) to adjust for pre-index costs, DCSI, pre-index insulin, age, and gender. RESULTS: Based on study criteria, 22,860 patients with MAPD coverage (17,292 sitagliptin, 4,282 saxagliptin, and 1,286 linagliptin) and 3,229 patients with commercial coverage (2,368 sitagliptin, 643 saxagliptin, and 218 linagliptin) were included. For MAPD patients, the mean age was 70-72 years, and females represented 50%-52% of patients. For commercial patients, mean age was 55-56 years, and females represented 44% of patients. Clinical indicators for patients on linagliptin showed a higher comorbidity level than sitagliptin or saxagliptin cohorts (MAPD DCSI 3.0 vs 2.4 and 2.2, P < 0.001; commercial DCSI 1.2 vs. 0.9 and 0.9, P < 0.001); a higher use of pre-index insulin (MAPD 22% vs. 15% and 14%, P < 0.001; commercial 18% vs. 11% and 10%, P = 0.003); and higher mean pre-index costs (MAPD $14,448 vs. $11,818 and $10,399, P < 0.001; commercial $13,868 vs. $9,357 and $8,223, P = 0.016). For the MAPD cohort, the unadjusted PDC was lower for linagliptin patients (67%) compared with saxagliptin (72%) or sitagliptin (72%) patients (P < 0.001). Significant differences were still seen when adjusted for covariates. Linagliptin patients were more likely to be nonpersistent (73%) than those on saxagliptin (65%) or sitagliptin (67%; P < 0.01 for adjusted and unadjusted comparisons). For the commercial population, there were no significant differences in mean PDC between the 3 groups (linagliptin 70%, saxagliptin 72%, and sitagliptin 74%; P = 0.096). Dichotomized comparisons of nonpersistence were significantly different (linagliptin 65%, saxagliptin 62%, and sitagliptin 57%; P = 0.010), although upon adjustment using a Cox proportional hazard model, no significant differences were found. When controlling for other factors, post-index adjusted health care costs were similar between the medication cohorts (MAPD: sitagliptin = $13,913, saxagliptin = $13,651, and linagliptin = $13,859; commercial: sitagliptin = $11,677, saxagliptin = $12,059, and linagliptin = $11,163; all P > 0.25). CONCLUSIONS: For MAPD and commercial populations, baseline patient demographics were similar between the 3 DPP-4 inhibitor groups, but the linagliptin group may have had more complex patients (higher pre-index costs, higher DCSI, and more use of insulin). For the MAPD population, patients on linagliptin were less adherent and persistent than patients taking sitagliptin or saxagliptin for all unadjusted and adjusted comparisons. For the commercial population, which was notably smaller, these differences were in the same direction, but not all were statistically significant. When controlling for baseline factors, 12-month post-index direct medical health care costs were similar between index DPP-4 inhibitors. DISCLOSURES: No external funding was provided for this research. The project was done as part of internal work by Humana employees. Rascati received no compensation. None of the authors have any financial disclosures or conflicts of interests to report. Worley and Everhart are employees of Comprehensive Health Insights, a subsidiary of Humana, and Meah is an employee of Humana. Discussion of the adherence and persistence data was presented as a poster at the Academy of Managed Care Pharmacy Nexus Conference, October 2015. Cost data were presented as a poster at the International Society for Pharmacoeconomics and Outcomes Research 18th Annual European Congress, November 2015. Study concept and design were contributed by Rascati, Worley, and Meah, along with Everhart. Rascati took the lead in data collection, assisted by Meah, and data interpretation was performed by all the authors. The manuscript was written primarily by Rascati, along with Worley, Everhart, and Meah, and revised by Rascati, Everhart, and Worley, with assistance from Meah.