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.