Cost-effectiveness of sitagliptin-based treatment regimens in European patients with type 2 diabetes and haemoglobin A1c above target on metformin monotherapy

A cost-effectiveness analysis of linagliptin add-on to insulin treatment for patients with type 2 diabetes mellitus and chronic kidney disease in Iran

Purpose

With the high prevalence of chronic kidney disease (CKD) in patients with type 2 diabetes mellitus (T2DM), determining optimal treatment strategies has become a major concern. Linagliptin is aDPP-4 inhibitor that does not require dose adjustment in patients with renal impairment. This study evaluates the cost-effectiveness of adding linagliptin to insulin therapy in patients with T2DM and mild (stage 2) or moderate (stage 3) CKD from a health system perspective in Iran.

Methods

We developed a cost-utility model using a decision tree and ran it separately for T2DM patients with mild or moderate CKD. Clinical outcomes and health-state utility values were extracted from published studies. Direct medical costs were obtained from national tariffs in Iran in 2021. We adopted an annual time horizon and calculated the difference in costs and quality-adjusted life-years (QALYs) to obtain the incremental cost-effectiveness ratios (ICER). To capture parameter uncertainties, one-way sensitivity analyses were also performed.

Results

In T2DM patients with mild CKD, the linagliptin add-on strategy was associated with an additional $23.69 cost and 0.0148 QALYs per patient, resulting in an ICER of 1600.37 USD/QALY. In moderate CKD, the strategy was associated with $22.59 more costs and 0.0191 more QALYs, and the ICER was estimated at 1182.72 USD/QALY. In both populations, the ICER was mainly driven by the impact of HbA1c on utility, cost of linagliptin, and the reduction in insulin usage by adding linagliptin to the treatment.

Conclusion

With a cost-effectiveness threshold of $1550 USD/QALY in Iran, adding linagliptin to insulin is cost-effective in patients with T2DM and moderate CKD. However, for those with mild CKD, it seems that the associated costs outweigh the expected benefits.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-023-01243-z.

Cost-Effectiveness of Newer Antidiabetic Drugs as Second-Line Treatment for Type 2 Diabetes: A Systematic Review

INTRODUCTION

Evidence from cardiovascular outcome trials (CVOTs) for newer antidiabetic drugs is increasingly influencing revised recommendations for second-line therapy in type 2 diabetes (T2D). This systematic review aimed to compare the cost-effectiveness of newer antidiabetic drugs specified as sodium-glucose cotransporter 2 inhibitor (SGLT2i), glucagon-like peptide 1 receptor agonist (GLP-1RA), and dipeptidyl peptidase 4 inhibitor (DPP-4i) for T2D in a second-line setting.

METHODS

A systematic review was conducted following the Preferred Reporting Items for Systematic Reviews (PRISMA) guidelines, and all relevant published studies were searched comprehensively in electronic databases, including PubMed, Embase, Web of Science, and International Health Technology Assessment database published from April 2023. The quality of the included studies was evaluated using Consolidated Health Economic Evaluation Reporting Standards (CHEERS) 2022 reporting checklists.

RESULTS

We included 28 studies that met the inclusion criteria. Overall reporting of the identified studies largely met CHEERS 2022 recommendations. The CORE and Cardiff models were the most frequently utilized for pharmacoeconomic evaluation in T2D. Four studies consistently discovered that SGLT2i was more cost-effective than GLP-1RA in T2D who were not adequately controlled by metformin monotherapy. Four studies compared GLP-1RA with DPP-4i, sufonylurea (SU), or insulin. Except for one that demonstrated SU was cost-effective, all were GLP-1RA. Five studies revealed that SGLT2i was more cost-effective than DPP-4i or SU. Eleven studies indicated that DPP-4i was more cost-effective than traditional antidiabetic drugs. Four additional studies explored the cost-effectiveness of various antidiabetic drugs as second-line options, indicating that SU, SGLT2i, or meglitinides were more economically advantageous. The most common driven factors were the cost of new antidiabetic drugs.

CONCLUSION

Newer antidiabetic drugs as second line are the cost-effective option for T2D from the cost-effectiveness perspective, especially SGLT2i.

DPP-4 inhibitors for treating T2DM - hype or hope? an analysis based on the current literature

DPP-4 inhibition is an interesting line of therapy for treating Type 2 Diabetes Mellitus (T2DM) and is based on promoting the incretin effect. Here, the authors have presented a brief appraisal of DPP-4 inhibitors, their modes of action, and the clinical efficiency of currently available drugs based on DPP-4 inhibitors. The safety profiles as well as future directions including their potential application in improving COVID-19 patient outcomes have also been discussed in detail. This review also highlights the existing queries and evidence gaps in DPP-4 inhibitor research. Authors have concluded that the excitement surrounding DPP-4 inhibitors is justified because in addition to controlling blood glucose level, they are good at managing risk factors associated with diabetes.

Pharmacoeconomic evaluation of dipeptidyl peptidase-4 inhibitors for the treatment of type 2 diabetes mellitus: a systematic literature review

INTRODUCTION

Dipeptidyl peptidase-4 inhibitors (DPP-4i) are widely used oral antidiabetic agents that exert antihyperglycemic effects in type 2 diabetes mellitus (T2DM) without increased risk of weight gain or hypoglycemic events. The objective of this paper was to systematically review the latest evidence that was associated with the pharmacoeconomic evaluation of DPP-4i for the treatment of patients with T2DM.

AREAS COVERED

We conducted a systematic literature search of eligible articles published since inception up to March 2021 in Web of Science, MEDLINE (via PubMed), and ECONLIT. Fifty-four eligible articles were included in our review, in which DPP-4i were compared to metformin (4 studies), sulphonylurea (SU) (16 studies), alpha-glucosidase inhibitors (AGI) (3 studies), thiazolidinediones (TZD) (4 studies), other DPP-4i (3 studies), sodium-glucose co-transporter-2 inhibitors (SGLT-2i) (10 studies), glucagon-like peptide 1 receptor agonist (GLP-1RA) (18 studies), insulin (5 studies), and other antidiabetic therapies (5 studies).

EXPERT OPINION

This study provided the updated evidence of systematic pharmacoeconomic evaluation associated with DPP-4i for the treatment of patients with T2DM. The evidence from the literature suggested that DPP-4i may be more cost-effective compared to SU and insulin as second-line therapy after metformin but not a cost-effective alternative compared to SGLPT-2i and GLP-1RA.

Health Utilities in Patients with Type 2 Diabetes in Taiwan

We aimed to measure health utilities in patients with diabetes mellitus (DM) in Taiwan and to estimate the impact of common DM-related complications and adverse effects (AEs) on health utilities. The present study was a cross-sectional survey of DM patients at a metropolitan hospital. Respondents’ health-related quality of life (HRQoL) was assessed by the EQ-5D-5L, and ordinary least-squares (OLS) regression was used to estimate the impact of self-reported DM-related complications and AEs on health utilities after controlling for age, gender, and duration of DM. A total of 506 eligible adults with type 2 DM (T2DM) were enrolled. The EQ-5D index values in our study sample ranged from −0.13 to 1, with a mean ± standard deviation of 0.88 ± 0.20. As indicated by the negative regression coefficients, the presence of any complication or AE was associated with lower EQ-5D index values, and the greatest impact on the score was made by amputation (−0.276), followed by stroke (−0.211), and blindness (−0.203). In conclusion, the present study elicited health utilities in patients with T2DM in Taiwan using the EQ-5D-5L. These estimated utility decrements provided essential data for future DM cost–utility analyses that are needed as a result of the increasing prevalence and health expenditures of DM.

Cost-Effectiveness Analysis of Exenatide versus GLP-1 Receptor Agonists in Patients with Type 2 Diabetes Mellitus

OBJECTIVE

The aim of this study was to assess the efficiency of exenatide 2 mg/week compared with other glucagon-like peptide-1 (GLP-1) receptor agonists (dulaglutide 1.5 mg/week, liraglutide 1.2 mg/day, liraglutide 1.8 mg/day and lixisenatide 20 μg/day) in adult patients with type 2 diabetes mellitus (T2DM) not adequately controlled on metformin alone from the perspective of the Spanish National Health System (NHS).

METHODS

Quality-adjusted life-years (QALYs) gained and total costs of each assessed drug combined with metformin (2 g/day) were estimated over a 40-year time horizon using the Cardiff Diabetes Model (based on UK Prospective Diabetes Study [UKPDS] 68 equations), which simulates disease progression considering the T2DM-related micro- and macrovascular complications, hypoglycaemia, nausea, body mass index (BMI) changes and treatment discontinuation due to adverse effects (AEs). Drug efficacy derived from an indirect comparison performed in a network meta-analysis. Patient characteristics were obtained from the literature. The baseline utility value (0.80) was derived from the PANORAMA study, applying utility decrements to micro- and macrovascular complications, hypoglycaemia episodes and changes in BMI. Treatment discontinuation due to AEs or poorly controlled diabetes (HbA1c > 7.5%) involved switching to second-line (basal insulin) or third-line (basal-bolus insulin) treatment. Total cost (€, 2018) included the costs of drug acquisition, hypoglycaemia, weight gain, micro- and macrovascular complications, nausea and treatment discontinuation due to AEs. An annual discount rate of 3% was applied to costs and outcomes. Deterministic and probabilistic sensitivity analyses (SA) were performed.

RESULTS

In base-case, exenatide 2 mg/week resulted in more QALYs (8.26) than dulaglutide 1.5 mg/week (8.19 QALYs), liraglutide 1.2 mg/day (8.10 QALYs), liraglutide 1.8 mg/day (8.20 QALYs) and lixisenatide 20 μg/day (8.13 QALYs). Total cost/patient was €20,423.27 (exenatide 2 mg/week), €22,611.94 (dulaglutide 1.5 mg/week), €21,065.97 (liraglutide 1.2 mg/day), €24,865.69 (liraglutide 1.8 mg/day) and €21,334.58 (lixisenatide 20 μg/day). Deterministic SA confirmed the robustness of the model. In the probabilistic SA, 95-99% of the 1000 Monte Carlo iterations performed were under a hypothetical willingness-to-pay threshold of €20,000/QALY gained.

CONCLUSIONS

Exenatide 2 mg/week would be a dominant strategy (more effective and less costly) versus the other GLP-1 receptor agonists assessed for the treatment of T2DM patients who are not adequately controlled on metformin alone.

Cost Effectiveness of Sodium-Glucose Cotransporter-2 (SGLT2) Inhibitors, Glucagon-Like Peptide-1 (GLP-1) Receptor Agonists, and Dipeptidyl Peptidase-4 (DPP-4) Inhibitors: A Systematic Review

OBJECTIVE

This study aimed to systematically review cost-effectiveness studies of newer antidiabetic medications.

METHODS

The PubMed/MEDLINE, EMBASE, CINAHL Plus, Cochrane Library-NHS Economic Evaluation Database (Wiley), Cochrane Library-Health Technology Assessment Database (Wiley), Cochrane Library-Database of Abstracts of Reviews of Effects (Wiley), and the Cost-Effectiveness Analysis Registry databases (from 1 January 2000 to 1 June 2018) were searched. The search strategies included the Medical Subject Heading (MeSH) term 'economics', and the MeSH entry terms 'cost', 'cost effectiveness', 'value', and 'cost utility', as well as all names for GLP-1 receptor agonists, DPP-4 inhibitors, and SGLT2 inhibitors. Inclusion criteria included (1) cost-effectiveness studies of the newer antidiabetic medications, including sodium-glucose cotransporter-2 (SGLT2) inhibitors, glucagon-like peptide-1 (GLP-1) receptor agonists, and dipeptidyl peptidase-4 (DPP-4) inhibitors; and (2) full-text publications in English. Two reviewers independently screened the titles, abstracts, and full-text articles to select studies for data extraction. Discrepancies were resolved by discussion and consensus. The quality of reporting cost-effectiveness analyses was assessed using the Consolidated Health Economic Evaluation Reporting Standards (CHEERS) guideline.

RESULTS

Among 85 studies selected, 82 clearly stated the types of diabetes model used (e.g. CORE model), and 70 studied used validated diabetes models. Seventy-four (87%) studies were funded by pharmaceutical companies, and 72 (85%) studies were conducted from a payer's perspective. Seventy-six (89%) studies presented were of good quality (20-24 CHEERS items), and nine were of moderate quality (14-19 items). Thirty studies compared newer antidiabetic medications with insulin, 3 studies compared newer antidiabetic medications with thiazolidinediones (TZDs), 15 studies compared newer antidiabetic medications with sulfonylureas, 40 studies compared new antidiabetic medications with alternative newer antidiabetic medication, and 9 studies compared other antidiabetic agents that were not included above. Newer antidiabetic medications were reported to be cost-effective in 26 of 30 (87%) studies compared with insulin, and 13 of 15 (87%) studies compared with sulfonylureas.

CONCLUSIONS

Most economic evaluations of antidiabetic medications have good reporting quality and use validated diabetes models. The newer antidiabetic medications in most of the reviewed studies were found to be cost effective, compared with insulin, TZDs, and sulfonylureas.

Cost-Effectiveness of Continuous Subcutaneous Insulin Infusion Versus Multiple Daily Injections in Patients with Poorly Controlled Type 2 Diabetes in Finland

INTRODUCTION

Although primarily utilized in type 1 diabetes, continuous subcutaneous insulin infusion (CSII) represents a useful treatment alternative for patients with type 2 diabetes who are unable to achieve good glycemic control despite optimization of multiple daily injections (MDI). The aim of the analysis reported here was to investigate the long-term cost-effectiveness of CSII versus MDI in type 2 diabetes patients with poor glycemic control in Finland.

METHODS

The IQVIA CORE Diabetes Model was used to make long-term projections of the clinical and economic outcomes associated with CSII use in type 2 diabetes, based on clinical input data from the OpT2mise trial, which showed that CSII was associated with a 1.1% decrease in glycated hemoglobin (HbA1c) in patients with poor glycemic control at baseline. The analysis was performed from a societal perspective and the time horizon was that of patient lifetimes. Future costs and clinical outcomes were discounted at 3% per annum.

RESULTS

Continuous subcutaneous insulin infusion was associated with a gain in quality-adjusted life expectancy of 0.32 quality-adjusted life-years (QALYs) compared with MDI (8.15 vs. 7.83 QALYs, respectively), as well as higher mean lifetime costs, resulting in an incremental cost-effectiveness ratio of Euro (EUR) 47,834 per QALY gained for CSII versus MDI. The higher treatment costs in the CSII group were partly mitigated by a 15% reduction in diabetes-related complication costs. Sensitivity analyses demonstrated that CSII was most cost-effective in patients with the highest baseline HbA1c values.

CONCLUSION

In Finland, CSII is likely to represent a cost-effective treatment alternative for patients with type 2 diabetes with poor glycemic control despite optimization of MDI. In such patients, CSII is associated with improved clinical outcomes relative to MDI, with the higher acquisition costs partly offset by a lower lifetime incidence and cost of diabetes-related complications.

FUNDING

Medtronic International Sàrl.

Cost-effectiveness and budget impact of liraglutide in type 2 diabetes patients with elevated cardiovascular risk: a US-managed care perspective

BACKGROUND

The Liraglutide Effect and Action in Diabetes: Evaluation of Cardiovascular Outcomes Results (LEADER) clinical trial demonstrated that liraglutide added to standard-of-care (SoC) therapy for type 2 diabetes (T2D) with established cardiovascular disease (CVD) or elevated cardiovascular (CV) risk was associated with lower rates of death from CVD, nonfatal myocardial infarction (MI), or nonfatal stroke than SoC alone.

OBJECTIVE

The objective of this study was to assess the cost-effectiveness (CE) and budget impact of liraglutide vs SoC in T2D patients with established CVD or elevated CV risk, over a lifetime horizon from a US managed care perspective.

METHODS

A cohort state-transition model (costs and benefits discounted at 3% per year) was used to predict diabetes-related complications and death (CV and all-cause). Events, treatment effects, and discontinuation rates were from LEADER trial; utility and cost data (US$, 2017) were from literature. Sensitivity analysis explored the impact of uncertainty on results. Additionally, a budget impact analysis was conducted to evaluate the financial impact of liraglutide use in this population, with displacement from dulaglutide, assuming a health care plan with 1 million members.

RESULTS

Liraglutide patients experienced 6.3% fewer events, had event-related cost-savings of $15,182, gained additional life-years of 0.67 and quality-adjusted life-years (QALYs) of 0.57, and had additional total costs ($60,928) vs SoC. Liraglutide was cost-effective with an incremental CE ratio of $106,749/QALY which was below the willingness-to-pay threshold of $150,000/QALY accepted by the Institute of Clinical and Economic Research. Liraglutide was cost-effective across all sensitivity analyses, except when the hazard ratio for all-cause mortality varied. The budget impact was neutral, with a per-plan-per-year and per-member-per-month cost-savings of $266,334 and $0.02, respectively.

CONCLUSION

From a US-managed care perspective, for T2D patients with established CVD or elevated CV risk, liraglutide is a cost-effective and a budget neutral treatment option for health care plans.

Novel Risk Engine for Diabetes Progression and Mortality in USA: Building, Relating, Assessing, and Validating Outcomes (BRAVO)

BACKGROUND

There is an urgent need to update diabetes prediction, which has relied on the United Kingdom Prospective Diabetes Study (UKPDS) that dates back to 1970 s' European populations.

OBJECTIVE

The objective of this study was to develop a risk engine with multiple risk equations using a recent patient cohort with type 2 diabetes mellitus reflective of the US population.

METHODS

A total of 17 risk equations for predicting diabetes-related microvascular and macrovascular events, hypoglycemia, mortality, and progression of diabetes risk factors were estimated using the data from the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial (n = 10,251). Internal and external validation processes were used to assess performance of the Building, Relating, Assessing, and Validating Outcomes (BRAVO) risk engine. One-way sensitivity analysis was conducted to examine the impact of risk factors on mortality at the population level.

RESULTS

The BRAVO risk engine added several risk factors including severe hypoglycemia and common US racial/ethnicity categories compared with the UKPDS risk engine. The BRAVO risk engine also modeled mortality escalation associated with intensive glycemic control (i.e., glycosylated hemoglobin < 6.5%). External validation showed a good prediction power on 28 endpoints observed from other clinical trials (slope = 1.071, R² = 0.86).

CONCLUSION

The BRAVO risk engine for the US diabetes cohort provides an alternative to the UKPDS risk engine. It can be applied to assist clinical and policy decision making such as cost-effective resource allocation in USA.

Longitudinal medical resources and costs among type 2 diabetes patients participating in the Trial Evaluating Cardiovascular Outcomes with Sitagliptin (TECOS)

AIMS

TECOS, a cardiovascular safety trial (ClinicalTrials.gov identifier: NCT00790205) involving 14 671 patients with type 2 diabetes and cardiovascular disease, demonstrated that sitagliptin was non-inferior to placebo for the primary composite cardiovascular outcome when added to best usual care. This study tested hypotheses that medical resource use and costs differed between these 2 treatment strategies.

MATERIALS AND METHODS

Information concerning medical resource use was collected on case report forms throughout the trial and was valued using US costs for: Medicare payments for hospitalizations, medical procedures and outpatient visits, and wholesale acquisition costs (WAC) for diabetes-related medications. Hierarchical generalized linear models were used to compare resource use and US costs, accounting for variable intercountry practice patterns. Sensitivity analyses included resource valuation using English costs for a UK perspective.

RESULTS

There were no significant differences in hospitalizations, inpatient days, medical procedures, or outpatient visits during follow-up (mean and median 3.0 years in both groups). Hospitalization rates appeared to diverge after 2 years, with lower rates among sitagliptin-treated vs placebo patients after 2.5 years (relative rate, 0.90 [95% CI, 0.83-0.97]; P = .01). Mean medical costs, exclusive of study medication, were 11 937 USD in the sitagliptin arm and 12 409 USD in the placebo arm (P = .06). Mean sitagliptin costs based on undiscounted WAC were 9978 USD per patient. Differential UK total costs including study drug costs were smaller (911 GBP), primarily because of lower mean costs for sitagliptin (1072 GBP).

CONCLUSIONS

Lower hospitalization rates across time with sitagliptin slightly offset sitagliptin treatment costs over 3 years in type 2 diabetes patients at high risk for cardiovascular events.

Comparison of costs and outcomes of dapagliflozin with other glucose-lowering therapy classes added to metformin using a short-term cost-effectiveness model in the US setting

OBJECTIVE

To compare 1-year costs and benefits of dapagliflozin (DAPA), a sodium-glucose cotransporter-2 (SGLT-2) inhibitor, with those of other treatments for type 2 diabetes (T2D), such as glucagon-like peptide-1 receptor agonists (GLP-1RAs), sulfonylureas (SUs), thiazolidinediones (TZDs), and dipeptidyl peptidase-4 inhibitors (DPP-4i), all combined with metformin.

METHODS

A short-term decision-analytic model with a 1-year time horizon was developed from a payer's perspective in the United States setting. Costs and benefits associated with four clinical end-points (glycated hemoglobin [A1C], body weight, systolic blood pressure [SBP], and risk of hypoglycemia) were evaluated in the analysis. The impact of DAPA and other glucose-lowering therapy classes on these clinical end-points was estimated from a network meta-analysis (NMA). Data for costs and quality-adjusted life-years (QALYs) associated with a per-unit change in these clinical end-points were taken from published literature. Drug prices were taken from an annual wholesale price list. All costs were inflation-adjusted to December 2016 costs using the medical care component of the consumer price index. Total costs (both medical and drug costs), total QALYs, and incremental cost-effectiveness ratios (ICERs) were estimated. Sensitivity analyses (SA) were performed to explore uncertainty in the inputs. To assess face validity, results from the short-term model were compared with long-term models published for these drugs.

RESULTS

The total annual medical cost for DAPA was less than that for GLP-1RA ($186 less), DPP-4i ($1,142 less), SU ($2,474 less), and TZD ($1,640 less). Treatment with DAPA resulted in an average QALY gain of 0.0107, 0.0587, 0.1137, and 0.0715 per treated patient when compared with GLP-1RA, DPP-4i, SU, and TZD, respectively. ICERs for DAPA vs SU and TZD were $19,005 and $25,835, respectively. DAPA was a cost-saving option when compared with GLP-1RAs and DPP-4is. Among all four clinical end-points, change in weight had the greatest impact on total annual costs and ICERS. Sensitivity analysis showed that results were robust, and results from the short-term model were found to be similar to those of published long-term models.

CONCLUSION

This analysis showed that DAPA was cost-saving compared with GLP-1RA and DPP-4i, and cost-effective compared with SU and TZD in the US setting over 1 year. Furthermore, the results suggest that, among the four composite clinical end-points, change in weight and SBP had an impact on cost-effectiveness results.

Incremental Costs and Cost Effectiveness of Intensive Treatment in Individuals with Type 2 Diabetes Detected by Screening in the ADDITION-UK Trial: An Update with Empirical Trial-Based Cost Data

BACKGROUND

There is uncertainty about the cost effectiveness of early intensive treatment versus routine care in individuals with type 2 diabetes detected by screening.

OBJECTIVES

To derive a trial-informed estimate of the incremental costs of intensive treatment as delivered in the Anglo-Danish-Dutch Study of Intensive Treatment in People with Screen-Detected Diabetes in Primary Care-Europe (ADDITION) trial and to revisit the long-term cost-effectiveness analysis from the perspective of the UK National Health Service.

METHODS

We analyzed the electronic primary care records of a subsample of the ADDITION-Cambridge trial cohort (n = 173). Unit costs of used primary care services were taken from the published literature. Incremental annual costs of intensive treatment versus routine care in years 1 to 5 after diagnosis were calculated using multilevel generalized linear models. We revisited the long-term cost-utility analyses for the ADDITION-UK trial cohort and reported results for ADDITION-Cambridge using the UK Prospective Diabetes Study Outcomes Model and the trial-informed cost estimates according to a previously developed evaluation framework.

RESULTS

Incremental annual costs of intensive treatment over years 1 to 5 averaged £29.10 (standard error = £33.00) for consultations with general practitioners and nurses and £54.60 (standard error = £28.50) for metabolic and cardioprotective medication. For ADDITION-UK, over the 10-, 20-, and 30-year time horizon, adjusted incremental quality-adjusted life-years (QALYs) were 0.014, 0.043, and 0.048, and adjusted incremental costs were £1,021, £1,217, and £1,311, resulting in incremental cost-effectiveness ratios of £71,232/QALY, £28,444/QALY, and £27,549/QALY, respectively. Respective incremental cost-effectiveness ratios for ADDITION-Cambridge were slightly higher.

CONCLUSIONS

The incremental costs of intensive treatment as delivered in the ADDITION-Cambridge trial were lower than expected. Given UK willingness-to-pay thresholds in patients with screen-detected diabetes, intensive treatment is of borderline cost effectiveness over a time horizon of 20 years and more.

The place of DPP-4 inhibitors in the treatment algorithm of diabetes type 2: a systematic review of cost-effectiveness studies

OBJECTIVE

To conduct a systematic review of cost-effectiveness, cost-utility, and cost-benefit studies of DPP-4 inhibitors for diabetes treatment versus other antidiabetics.

METHODS

Three investigators searched the CRD York, Tufts CEA Registry, and MEDLINE databases through 2015. We reviewed all potentially relevant titles and abstracts, and screened full-text articles, according to inclusion criteria. We established a quality score for each study based on a 35-item list.

RESULTS

A total of 295 studies were identified, of which 20 were included. The average quality score was 0.720 on a 0-1 scale. All studies were performed in high- and middle-income countries, using a 3rd-party payer perspective and randomized clinical trials to measure effectiveness. Sitagliptin, saxagliptin and vildagliptin had an ICER below 25,000 €/QALY, as second-line and as add-ons to metformin, in comparison to sulfonylureas. When compared with sitagliptin, liraglutide (GLP-1 receptor agonist) had an ICER of up to 22,724 €/QALY for the 1.2-mg dosage, and up to 32,869 €/QALY for the 1.8-mg dosage. Insulin glargine was dominant when compared with sitagliptin.

CONCLUSIONS

According to the WHO threshold applied to the country and year of each study, DPP-4 inhibitors were highly cost-effective as second-line, as add-ons to metformin, in comparison with sulfonylureas. More recent therapies (GLP-1 receptor agonists and insulin glargine) were highly cost-effective in comparison to DPP-4 inhibitors. These results were obtained, however, on the basis of a limited number of studies, relying on the same few clinical trials, and financed by manufacturers. Further independent research is needed to confirm these findings.

Cost-effectiveness of dipeptidyl peptidase-4 inhibitor monotherapy versus sulfonylurea monotherapy for people with type 2 diabetes and chronic kidney disease in Thailand

OBJECTIVE

With a high prevalence of chronic kidney disease (CKD) in type 2 diabetes (T2DM) in Thailand, the appropriate treatment for the patients has become a major concern. This study aimed to evaluate long-term cost-effective of dipeptidyl peptidase-4 (DPP-4) inhibitor monothearpy vs sulfonylurea (SFU) monotherapy in people with T2DM and CKD.

METHODS

A validated IMS CORE Diabetes Model was used to estimate the long-term costs and outcomes. The efficacy parameters were identified and synthesized using a systematic review and meta-analysis. Baseline characteristics and cost parameters were obtained from published studies and hospital databases in Thailand. Costs were expressed in 2014 US Dollars. Outcomes were presented as an incremental cost-effectiveness ratio (ICER). One-way and probabilistic sensitivity analyses were performed to estimate parameter uncertainty.

RESULTS

From a societal perspective, treatment with DPP-4 inhibitors yielded more quality-adjusted life years (QALYs) (0.024) at a higher cost (>66,000 Thai baht (THB) or >1,829.27 USD) per person than SFU, resulting in the ICER of >2.7 million THB/QALY (>74,833.70 USD/QALY). The cost-effectiveness results were mainly driven by differences in HbA1c reduction, hypoglycemic events, and drug acquisition cost of DPP-4 inhibitors. At the ceiling ratio of 160,000 THB/QALY (4,434.59 USD/QALY), the probability that DPP-4 inhibitors are cost-effective compared to SFU was less than 10%.

CONCLUSIONS

Compared to SFU, DPP-4 inhibitor monotherapy is not a cost-effective treatment for people with T2DM and CKD in Thailand.

Comparison of charges and resource use associated with saxagliptin and sitagliptin

OBJECTIVES

Saxagliptin and sitagliptin are two commonly used dipeptidyl peptidase-4 (DPP-4) inhibitors. Little is known about their comparative effectiveness in the real world, particularly their impact on cost and resources use. The objective of this study was to analyze charges and resource use associated with saxagliptin and sitagliptin to understand the impact of these DPP-4 inhibitor treatment options in a real-world setting.

METHODS

This was a retrospective, new-user study approved by the Institutional Review Board at the University of Toledo. Data were collected from a US insurance claims dataset (OptumInsight) for patients newly initiating treatment with saxagliptin or sitagliptin between January 1, 2010 and December 31, 2011. ICD-9 code 250 was used to identify patients with T2D. Overall and diabetes-related medical and pharmacy charges were observed. Inpatient hospitalizations were also compared. Propensity score matching was used to balance the cohorts of patients prescribed saxagliptin and sitagliptin. Appropriate univariate statistical tests were applied to the propensity-matched sample to examine differences in resource utilization outcomes. Statistical significance was evaluated at P < 0.05.

RESULT

After the propensity score matching, each cohort included 7711 patients. Saxagliptin treatment was associated with lower overall charges ($13,292 vs $14,032; P = 0.0023) and overall medical charges ($9,540 vs $10,296; P = 0.0024) during the 6-month follow-up period compared with sitagliptin treatment. No significant differences were observed in the overall pharmacy charges ($3,751 vs $3,753; P = 0.6937) and the diabetes-related charges ($5,141 vs $5,232; P = 0.2957). All-cause and diabetes-related inpatient hospitalization rates were significantly lower with saxagliptin treatment (p = 0.0001 and p = 0.0019, respectively). All-caused inpatient charges were also significantly lower with saxagliptin ($2,917.26 vs $3445.89; P < 0.0001).

CONCLUSION

Compared with patients initiating sitagliptin treatment, patients initiating saxagliptin treatment reported lower overall and medical charges and lower overall and diabetes-related hospitalization rates. These findings may aid payers in managing patients with T2D.

The Cost-Effectiveness of Alogliptin Versus Sulfonylurea as Add-on Therapy to Metformin in Patients with Uncontrolled Type 2 Diabetes Mellitus

INTRODUCTION

ENDURE (ClinicalTrials.gov identifier, NCT00856284), a multicenter, double-blind, active-controlled study of 2639 patients with uncontrolled type 2 diabetes mellitus (T2DM), found that metformin in combination with alogliptin (12.5 and 25 mg doses), when compared to standard add-on therapy (sulfonylurea, SU), exerted sustained antihyperglycemic effects over 2 years. This economic analysis of ENDURE aimed to quantify the relationship between increased glycemic durability and cost-effectiveness of alogliptin in the UK clinical setting, and communicate its sustained glycemic benefit in economic terms.

METHODS

Using baseline characteristics and treatment effects from the ENDURE trial population, between-group cost-effectiveness analyses compared the combined use of metformin and alogliptin (MET + ALO_12.5/25) in patients with inadequately controlled T2DM, as an alternative to metformin and SU (MET + SU). In scenario analyses, an intragroup cost-effectiveness analysis compared MET + ALO_12.5/25 with MET + SU; a between-group cost-effectiveness analysis also compared MET + ALO_12.5/25 versus MET + SU within a subpopulation of patients who achieved HbA1c control (<7.5%) at 2 years on study drug.

RESULTS

Compared with baseline profiles of patients, combination therapies with alogliptin or SU were associated with improvements in length and quality of life and were cost-effective at established norms. Despite increased drug acquisition costs, alogliptin at 12.5 mg and 25 mg doses resulted in greater predicted lifetime quality-adjusted life year (QALY) gains with associated incremental cost-effectiveness ratios (ICERs) of £10,959/QALY and £7217/QALY compared to SU, respectively.

CONCLUSION

The ENDURE trial and the present cost-effectiveness analysis found that the glycemic durability of alogliptin therapy was associated with improved long-term patient outcomes, QALY gains, and ICERs that were cost-effective when evaluated against standard threshold values. Alogliptin therefore represents a cost-effective treatment alternative to SU as add-on therapy to metformin in patients with poorly managed T2DM.

FUNDING

Takeda Development Centre Europe Ltd.

A randomised trial of the effect and cost-effectiveness of early intensive multifactorial therapy on 5-year cardiovascular outcomes in individuals with screen-detected type 2 diabetes: the Anglo-Danish-Dutch Study of Intensive Treatment in People with Screen-Detected Diabetes in Primary Care (ADDITION-Europe) study

BACKGROUND

Intensive treatment (IT) of cardiovascular risk factors can halve mortality among people with established type 2 diabetes but the effects of treatment earlier in the disease trajectory are uncertain.

OBJECTIVE

To quantify the cost-effectiveness of intensive multifactorial treatment of screen-detected diabetes.

DESIGN

Pragmatic, multicentre, cluster-randomised, parallel-group trial.

SETTING

Three hundred and forty-three general practices in Denmark, the Netherlands, and Cambridge and Leicester, UK.

PARTICIPANTS

Individuals aged 40-69 years with screen-detected diabetes.

INTERVENTIONS

Screening plus routine care (RC) according to national guidelines or IT comprising screening and promotion of target-driven intensive management (medication and promotion of healthy lifestyles) of hyperglycaemia, blood pressure and cholesterol.

MAIN OUTCOME MEASURES

The primary end point was a composite of first cardiovascular event (cardiovascular mortality/morbidity, revascularisation and non-traumatic amputation) during a mean [standard deviation (SD)] follow-up of 5.3 (1.6) years. Secondary end points were (1) all-cause mortality; (2) microvascular outcomes (kidney function, retinopathy and peripheral neuropathy); and (3) patient-reported outcomes (health status, well-being, quality of life, treatment satisfaction). Economic analyses estimated mean costs (UK 2009/10 prices) and quality-adjusted life-years from an NHS perspective. We extrapolated data to 30 years using the UK Prospective Diabetes Study outcomes model [version 1.3; (©) Isis Innovation Ltd 2010; see www.dtu.ox.ac.uk/outcomesmodel (accessed 27 January 2016)].

RESULTS

We included 3055 (RC, n = 1377; IT, n = 1678) of the 3057 recruited patients [mean (SD) age 60.3 (6.9) years] in intention-to-treat analyses. Prescription of glucose-lowering, antihypertensive and lipid-lowering medication increased in both groups, more so in the IT group than in the RC group. There were clinically important improvements in cardiovascular risk factors in both study groups. Modest but statistically significant differences between groups in reduction in glycated haemoglobin (HbA1c) levels, blood pressure and cholesterol favoured the IT group. The incidence of first cardiovascular event [IT 7.2%, 13.5 per 1000 person-years; RC 8.5%, 15.9 per 1000 person-years; hazard ratio 0.83, 95% confidence interval (CI) 0.65 to 1.05] and all-cause mortality (IT 6.2%, 11.6 per 1000 person-years; RC 6.7%, 12.5 per 1000 person-years; hazard ratio 0.91, 95% CI 0.69 to 1.21) did not differ between groups. At 5 years, albuminuria was present in 22.7% and 24.4% of participants in the IT and RC groups, respectively [odds ratio (OR) 0.87, 95% CI 0.72 to 1.07), retinopathy in 10.2% and 12.1%, respectively (OR 0.84, 95% CI 0.64 to 1.10), and neuropathy in 4.9% and 5.9% (OR 0.95, 95% CI 0.68 to 1.34), respectively. The estimated glomerular filtration rate increased between baseline and follow-up in both groups (IT 4.31 ml/minute; RC 6.44 ml/minute). Health status, well-being, diabetes-specific quality of life and treatment satisfaction did not differ between the groups. The intervention cost £981 per patient and was not cost-effective at costs ≥ £631 per patient.

CONCLUSIONS

Compared with RC, IT was associated with modest increases in prescribed treatment, reduced levels of risk factors and non-significant reductions in cardiovascular events, microvascular complications and death over 5 years. IT did not adversely affect patient-reported outcomes. IT was not cost-effective but might be if delivered at a reduced cost. The lower than expected event rate, heterogeneity of intervention delivery between centres and improvements in general practice diabetes care limited the achievable differences in treatment between groups. Further follow-up to assess the legacy effects of early IT is warranted.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00237549.

FUNDING DETAILS

This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 20, No. 64. See the NIHR Journals Library website for further project information.

How Do Diabetes Models Measure Up? A Review of Diabetes Economic Models and ADA Guidelines

Introduction: Economic models and computer simulation models have been used for assessing short-term cost-effectiveness of interventions and modelling long-term outcomes and costs. Several guidelines and checklists have been published to improve the methods and reporting. This article presents an overview of published diabetes models with a focus on how well the models are described in relation to the considerations described by the American Diabetes Association (ADA) guidelines. Methods: Relevant electronic databases and National Institute for Health and Care Excellence (NICE) guidelines were searched in December 2012. Studies were included in the review if they estimated lifetime outcomes for patients with type 1 or type 2 diabetes. Only unique models, and only the original papers were included in the review. If additional information was reported in subsequent or paired articles, then additional citations were included. References and forward citations of relevant articles, including the previous systematic reviews were searched using a similar method to pearl growing. Four principal areas were included in the ADA guidance reporting for models: transparency, validation, uncertainty, and diabetes specific criteria. Results: A total of 19 models were included. Twelve models investigated type 2 diabetes, two developed type 1 models, two created separate models for type 1 and type 2, and three developed joint type 1 and type 2 models. Most models were developed in the United States, United Kingdom, Europe or Canada. Later models use data or methods from earlier models for development or validation. There are four main types of models: Markov-based cohort, Markov-based microsimulations, discrete-time microsimulations, and continuous time differential equations. All models were long-term diabetes models incorporating a wide range of compilations from various organ systems. In early diabetes modelling, before the ADA guidelines were published, most models did not include descriptions of all the diabetes specific components of the ADA guidelines but this improved significantly by 2004. Conclusion: A clear, descriptive short summary of the model was often lacking. Descriptions of model validation and uncertainty were the most poorly reported of the four main areas, but there exist conferences focussing specifically on the issue of validation. Interdependence between the complications was the least well incorporated or reported of the diabetes-specific criterion.

The efficacy and safety of DPP4 inhibitors compared to sulfonylureas as add-on therapy to metformin in patients with Type 2 diabetes: A systematic review and meta-analysis

There is no consensus on the selection of specific drug therapies when metformin fails in Type 2 diabetes (T2D). This meta-analysis was performed to determine the efficacy and safety of Dipeptidyl peptidase-4 inhibitors (DPP4-I) compared to sulfonylurea (SU) as add-on therapy to metformin in inadequately controlled T2D patients. We searched MEDLINE, CENTRAL, EMBASE, and CINAHL for randomized trials comparing DPP4-I to SU as add-on therapy to metformin and reported a change in hemoglobin A1c (HbA1c). Sixteen articles were included. There was a significantly greater reduction in HbA1c from baseline to 12 weeks with SU versus DPP4-I (MD[95% CI]=0.21%(2 mmol/mol) [0.06, 0.35]) but no significant difference at 52 and 104 weeks (MD[95% CI]=0.06%(-1 mmol/mol) [-0.03, 0.15] and 0.02%(-1 mmol/mol) [-0.13,0.18] respectively). SU was associated with weight gain and DPP4-I with weight loss at all time-points. The incidence of hypoglycemia at 12, 52, and 104 weeks was significantly greater with SU (20%, 24%, and 27% respectively) compared to DPP4-I (6%, 3%, and 4% respectively). The proportion of patients with HbA1c<7%(53 mmol/mol) without hypoglycemia was significantly higher at 52 and 104 weeks among patients on DPP4-I (RR[95% CI]=1.20 [1.05, 1.37] and 1.53 [1.16, 2.02] respectively). There was no significant difference between the two groups in the incidence of other side effects. While both SU and DPP4-I can be considered as options for add-on therapy to metformin in inadequately controlled T2D, SU results in a significantly increased risk of hypoglycemia and weight gain. By contrast, DPP4-I produce 0.4-0.6% (4-7 mmol/mol) reduction in HbA1c, lower risk of hypoglycemia, and weight loss.

Cost-effectiveness of intensive multifactorial treatment compared with routine care for individuals with screen-detected Type 2 diabetes: analysis of the ADDITION-UK cluster-randomized controlled trial

AIMS

To examine the short- and long-term cost-effectiveness of intensive multifactorial treatment compared with routine care among people with screen-detected Type 2 diabetes.

METHODS

Cost-utility analysis in ADDITION-UK, a cluster-randomized controlled trial of early intensive treatment in people with screen-detected diabetes in 69 UK general practices. Unit treatment costs and utility decrement data were taken from published literature. Accumulated costs and quality-adjusted life years (QALYs) were calculated using ADDITION-UK data from 1 to 5 years (short-term analysis, n = 1024); trial data were extrapolated to 30 years using the UKPDS outcomes model (version 1.3) (long-term analysis; n = 999). All costs were transformed to the UK 2009/10 price level.

RESULTS

Adjusted incremental costs to the NHS were £285, £935, £1190 and £1745 over a 1-, 5-, 10- and 30-year time horizon, respectively (discounted at 3.5%). Adjusted incremental QALYs were 0.0000, - 0.0040, 0.0140 and 0.0465 over the same time horizons. Point estimate incremental cost-effectiveness ratios (ICERs) suggested that the intervention was not cost-effective although the ratio improved over time: the ICER over 10 years was £82,250, falling to £37,500 over 30 years. The ICER fell below £30 000 only when the intervention cost was below £631 per patient: we estimated the cost at £981.

CONCLUSION

Given conventional thresholds of cost-effectiveness, the intensive treatment delivered in ADDITION was not cost-effective compared with routine care for individuals with screen-detected diabetes in the UK. The intervention may be cost-effective if it can be delivered at reduced cost.

Cost effectiveness of dipeptidyl peptidase-4 inhibitors for type 2 diabetes

BACKGROUND

Dipeptidyl peptidase-4 (DPP-4) inhibitors are a new class of antidiabetic drugs used for treating type 2 diabetes mellitus. While many studies have reported on the cost-effectiveness of DPP-4 inhibitors for treating type 2 diabetes, a systematic review of economic evaluations of DPP-4 inhibitors is currently lacking.

OBJECTIVES

The aim of this systematic review was to assess the cost effectiveness of DPP-4 inhibitors for patients with type 2 diabetes.

DATA SOURCES

MEDLINE, EMBASE, National Health Service Economic Evaluation Database (NHS EED), Web of Science, EconLit databases, and the Cochrane Library were searched in November 2013.

STUDY ELIGIBILITY CRITERIA, PARTICIPANTS AND INTERVENTIONS

Studies assessing the cost effectiveness of DPP-4 inhibitors for type 2 diabetes were eligible for analysis. DPP-4 inhibitor monotherapy or combinations with other antidiabetic agents were included in the review. The DPP-4 inhibitors were all marketed drugs. Two reviewers independently reviewed titles, abstracts, and articles sequentially to select studies for data abstraction based on the inclusion and exclusion criteria. Disagreements were resolved by consensus.

STUDY APPRAISAL AND SYNTHESIS METHODS

The quality of included studies was assessed according to the 24-item checklist of the Consolidated Health Economic Evaluation Reporting Standards (CHEERS) statement. The costs reported by the included studies were converted to US dollars via purchasing power parities (PPP) in the year 2013 using the CCEMG-EPPI-Center Cost Converter.

RESULTS

A total of 11 published studies were selected for inclusion; all were cost-utility analyses. Nine studies were conducted from a payer perspective and one used a societal perspective; however, the perspective of the other study was unclear. Four studies were of good quality, six were of moderate quality, and one was of low quality. Of the seven studies comparing DPP-4 inhibitors plus metformin with sulfonylureas plus metformin, six concluded that DPP-4 inhibitors were cost effective in patients with type 2 diabetes who were no longer adequately controlled by metformin monotherapy. Five studies compared DPP-4 inhibitors with thiazolidinediones, and whether DPP-4 inhibitors were cost effective was uncertain. Only two economic evaluations provided data to compare DPP-4 inhibitors versus insulin, and the results favored the use of DPP-4 inhibitors as second-line therapy.

LIMITATIONS

Synthesis of the data was impossible because of heterogeneity in the methodology and data sources of the economic evaluations, and the inclusion criteria excluded conference abstracts. It was difficult to find reliable weightings for each of the items of the CHEERS checklist, and the ratings were dichotomous.

CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGS

This study provides the first systematic evaluation of DPP-4 inhibitors for patients with type 2 diabetes. It found that, in patients with type 2 diabetes who do not achieve glycemic targets with antidiabetic monotherapy, DPP-4 inhibitors as add-on treatment may represent a cost-effective option compared with sulfonylureas and insulin. However, high-quality cost-effectiveness analyses that utilize long-term follow-up data and have no conflicts of interest are still needed.

Management of patients with type 2 diabetes and mild/moderate renal impairment: profile of linagliptin

Dipeptidyl-peptidase-IV (DPP-4) inhibitors are oral antidiabetic agents that can be administered as monotherapy in patients with contraindications to metformin or metformin intolerance, and in combination with other oral compounds and/or insulin. DPP-4 inhibitors act in a glucose-dependent manner and only increase insulin secretion and inhibit glucagon secretion under hyperglycemic conditions. Renal impairment is frequent in type 2 diabetes as a result of microvascular complications and diabetes treatment, and options in these patients are limited. Linagliptin is a DPP-4 inhibitor with a hepatobiliary route of elimination. In comparative studies, it was noninferior to metformin and sulfonylureas in lowering glycated hemoglobin (HbA_1c) and improving glycemic parameters. It can be used throughout all stages of renal impairment without dose adjustments. This review gives an overview of linagliptin in various stages of chronic kidney disease and has a focus on efficacy and safety parameters from clinical studies in patients with impaired renal function. These data are interpreted in the context of type 2 diabetes therapy in general.

Cost-effectiveness of dapagliflozin (Forxiga®) added to metformin compared with sulfonylurea added to metformin in type 2 diabetes in the Nordic countries

AIMS

The aim of this study was to assess the long-term cost-effectiveness of dapagliflozin (Forxiga(®)) added to metformin, compared with sulfonylurea (SU) added to metformin, in Nordic Type 2 diabetes mellitus (T2DM) patients inadequately controlled on metformin.

METHODS

Data from a 52-week clinical trial comparing dapagliflozin and SU in combination with metformin was used in a Cardiff simulation model to estimate long term diabetes-related complications in a cohort of T2DM patients. Costs and QALYs were calculated from a healthcare provider perspective and estimated over a patient's lifetime.

RESULTS

Compared with metformin+SU, the cost per QALY gained with dapagliflozin+metformin was €7944 in Denmark, €5424 in Finland, €4769 in Norway, and €6093 in Sweden. Metformin+dapagliflozin was associated with QALY gains ranging from 0.236 in Norway to 0.278 in Sweden and incremental cost ranging from €1125 in Norway to €1962 in Denmark. Results were robust across both one-way and probabilistic sensitivity analyses. Results were driven by weight changes associated with each treatment.

CONCLUSIONS

Results indicate that metformin+dapagliflozin is associated with gains in QALY compared with metformin+SU in Nordic T2DM patients inadequately controlled on metformin. Dapagliflozin treatment is a cost-effective treatment alternative for Type 2 diabetes in all four Nordic countries.

Sitagliptin: a review of its use in patients with type 2 diabetes mellitus

Sitagliptin (Januvia(®), Xelevia™, Glactiv(®), Tesavel(®)) is an orally administered, potent and highly selective inhibitor of dipeptidyl peptidase-4 (DPP-4) and was the first agent of its class to be approved for use in the management of adults with type 2 diabetes. Numerous randomized placebo- or active comparator-controlled trials have demonstrated the efficacy of sitagliptin in terms of improving glycaemic control in patients with type 2 diabetes, including its use as monotherapy, initial combination therapy (usually with fixed-dose combinations of sitagliptin/metformin), or add-on therapy to metformin or to other antihyperglycaemic drugs, with or without metformin. The primary endpoint of the clinical trials was the reduction from baseline in glycosylated haemoglobin (HbA1c), although sitagliptin also showed beneficial effects for other endpoints, such as the proportion of patients who achieved target HbA1c, and reductions from baseline in fasting plasma glucose (FPG) levels and 2-h postprandial glucose (PPG) levels. Sitagliptin was generally well tolerated in clinical trials, had a low risk of hypoglycaemia (although this depends on background therapy) and had a neutral effect on body weight. Despite concerns regarding a possible increased risk of rare pancreatic adverse events (e.g. pancreatitis) with glucagon-like peptide-1 (GLP-1)-based therapies, such as GLP-1 receptor agonists and DPP-4 inhibitors, no causal association has been found; regulators in Europe recently conducted a review of available data, concluding that there is little evidence that these drugs could cause pancreatic inflammation or pancreatic cancer. A similar review is planned in the USA and postmarketing surveillance will continue. Thus, oral sitagliptin is an effective and generally well tolerated treatment option for the management of patients with type 2 diabetes.

Cost-effectiveness of saxagliptin vs glimepiride as a second-line therapy added to metformin in Type 2 diabetes in China

OBJECTIVE

This study aims to estimate the long-term cost-effectiveness of saxagliptin + metformin (SAXA + MET) vs glimepiride + metformin (GLI + MET) in patients with Type 2 diabetes mellitus (T2DM) inadequately controlled with MET in China.

METHODS

The Cardiff Model was used to simulate disease progression and estimate the long-term effect of treatments on patients. Systematic literature reviews and hospital surveys were conducted to obtain patients profiles, clinical data, and costs. Health insurance costs (2014¥) were estimated over a 40-year period. One-way and probabilistic sensitivity analyses were performed.

RESULTS

SAXA + MET had lower predicted incidences of cardiovascular and hypoglycemia events and a decreased total cost compared with GLI + MET (¥241,072,807 vs ¥285,455,177). There were increased numbers of quality-adjusted life-years (QALYs; 1.01/patient) and life-years (Lys; 0.03/patient) gained with SAXA + MET compared with GLI + MET, and the incremental cost of SAXA + MET vs GLI + MET (-¥44,382) resulted in -¥43,883/QALY and -¥1,710,926/LY gained with SAXA + MET. Sensitivity analyses confirmed that the results were robust.

CONCLUSION

In patients with T2DM in China, SAXA + MET was more cost-effective and was well tolerated with fewer adverse effects (AEs) compared with GLI + MET. As a second-line therapy for T2DM, SAXA may address some of the unmet medical needs attributable to AEs in the treatment of T2DM.

[Cost-effectiveness analysis of dapagliflozin compared to DPP4 inhibitors and other oral antidiabetic drugs in the treatment of type-2 diabetes mellitus in Spain]

Objetivo

Evaluar la eficiencia de la terapia combinada de metformina y dapagliflozina, un nuevo antidiabético oral con un mecanismo de acción independiente de la insulina, en el tratamiento de la diabetes mellitus tipo 2 (DM2) en comparación con inhibidores de DPP4, sulfonilureas y tiazolidindionas, combinados también con metformina.

Diseño

Análisis de coste-efectividad utilizando un modelo de simulación de eventos discretos a partir de los resultados de los ensayos clínicos disponibles y considerando un horizonte temporal de toda la vida del paciente.

Emplazamiento

Perspectiva del Sistema Nacional de Salud.

Participantes

El modelo simuló la historia natural de 30.000 pacientes con DM2 para cada opción comparada.

Mediciones principales

Años de vida ajustados por calidad (AVAC) y consecuencias económicas del manejo de la enfermedad y sus complicaciones. Se consideraron los costes directos (actualizados a euros de 2013) y se aplicó un descuento del 3% tanto para costes como para resultados en salud.

Resultados

El análisis principal comparó dapagliflozina con los inhibidores de DPP4, resultando dapagliflozina como una opción de tratamiento que aportaría una ligera mayor efectividad (0,019 AVAC) con menores costes totales asociados (−42 €). En los análisis adicionales, dapagliflozina fue una opción coste-efectiva en comparación con sulfonilureas y tiazolidindionas con razones de coste por AVAC ganado de 3.560 € y 2.007 €, respectivamente. Los análisis de sensibilidad univariantes y probabilístico confirmaron la solidez de los resultados.

Conclusiones

Los resultados del análisis realizado sugieren que dapagliflozina, en combinación con metformina, sería una alternativa coste-efectiva en el contexto español para el tratamiento de la DM2.

Clinical outcomes and health care costs combining metformin with sitagliptin or sulphonylureas or thiazolidinediones in uncontrolled type 2 diabetes patients

Objectives

To compare clinical outcomes and health care costs across three cohorts of uncontrolled diabetic patients who initiated treatment with one of the following: sulphonylureas (SU), thiazolidinediones (TZD) or sitagliptin (SITA).

Materials and methods

We performed a retrospective study based on a linkage between administrative and laboratory databases maintained by three Italian local health units. The index period ranged from July 2008–June 2010. Patients were treatment-naïve to either SU, TZD, or SITA, but they were already treated with other oral hypoglycemic agents. Demographics and clinical characteristics were assessed at baseline. Adherence was measured by the medication possession ratio and adherent was defined as a patient with a medication possession ratio of 80% or greater. We used a Poisson regression model to estimate the risk ratios for disease-related hospitalizations that occurred during the 18-month follow-up period. The total annual costs included all the pharmacological treatments and the direct costs due to hospitalizations and outpatient services.

Results

We identified 928 patients treated with SU, 330 patients treated with TZD, and 83 patients treated with SITA. SITA patients were significantly younger and with fewer previous hospital discharges. The baseline mean glycated hemoglobin level was 8.1% for SU, 8.0% for TZD, and 8.3% for SITA patients. SITA-naïve patients were more adherent than the SU- and TZD-naïve patients (79.5% versus 53.2% and 62.8%, respectively; P<0.001). The SU and TZD group showed a significant increased risk of disease-related hospitalizations compared with the SITA group (the unadjusted rate was 10.42 and 7.16 per 100 person-years versus 1.64 per 100 person-years, P=0.003; compared with SU, the adjusted incidence rate ratio for SITA was 0.21, P=0.030). The total annual costs per patient were €972 for SITA, €706 for SU, and €908 for those treated with TZD.

Conclusion

Uncontrolled diabetic patients who initiated – as a second-line therapy in addition to metformin – treatment with SITA, compared to those who initiated treatment with SU or TZD, showed a reduced risk of disease-related hospitalizations. The total annual costs per patient were not significantly different among the three groups.

Cost-effectiveness of metformin plus vildagliptin compared with metformin plus sulphonylurea for the treatment of patients with type 2 diabetes mellitus: a Portuguese healthcare system perspective

OBJECTIVE

To evaluate the cost-effectiveness of vildagliptin plus metformin vs generic sulphonylurea plus metformin in patients with type 2 diabetes mellitus, not controlled with metformin, from a Portuguese healthcare system perspective.

METHODS

A cost-effectiveness model was constructed using risk equations from the UK Prospective Diabetes Study Outcomes Model with a 10,000-patient cohort and a lifetime horizon. The model predicted microvascular and macrovascular complications and mortality in yearly cycles. Patients entered the model as metformin monotherapy failures and switched to alternative treatments (metformin plus basal-bolus insulin and subsequently metformin plus intensive insulin) when glycated hemoglobin A1c >7.5% was reached. Baseline patient characteristics and clinical variables were derived from a Portuguese epidemiological study. Cost estimates were based on direct medical costs only. One-way and probabilistic sensitivity analyses were conducted to test the robustness of the model.

RESULTS

There were fewer non-fatal diabetes-related adverse events (AEs) in patients treated with metformin plus vildagliptin compared with patients treated with metformin plus sulphonylurea (6752 vs 6815). Addition of vildagliptin compared with sulphonylurea led to increased drug acquisition costs but reduced costs of AEs, managing morbidities, and monitoring patients. Treatment with metformin plus vildagliptin yielded a mean per-patient gain of 0.1279 quality-adjusted life years (QALYs) and a mean per-patient increase in total cost of €1161, giving an incremental cost-effectiveness ratio (ICER) of €9072 per QALY. Univariate analyses showed that ICER values were robust and ranged from €4195 to €16,052 per QALY when different parameters were varied.

LIMITATIONS

The model excluded several diabetes-related morbidities, such as peripheral neuropathy and ulceration, and did not model second events. Patients were presumed to enter the model with no diabetes-related complications.

CONCLUSION

Treatment with metformin plus vildagliptin compared with metformin plus sulphonylurea is expected to result in a lower incidence of diabetes-related AEs and to be a cost-effective treatment strategy.

When to use discrete event simulation (DES) for the economic evaluation of health technologies? A review and critique of the costs and benefits of DES

Modelling in economic evaluation is an unavoidable fact of life. Cohort-based state transition models are most common, though discrete event simulation (DES) is increasingly being used to implement more complex model structures. The benefits of DES relate to the greater flexibility around the implementation and population of complex models, which may provide more accurate or valid estimates of the incremental costs and benefits of alternative health technologies. The costs of DES relate to the time and expertise required to implement and review complex models, when perhaps a simpler model would suffice. The costs are not borne solely by the analyst, but also by reviewers. In particular, modelled economic evaluations are often submitted to support reimbursement decisions for new technologies, for which detailed model reviews are generally undertaken on behalf of the funding body. This paper reports the results from a review of published DES-based economic evaluations. Factors underlying the use of DES were defined, and the characteristics of applied models were considered, to inform options for assessing the potential benefits of DES in relation to each factor. Four broad factors underlying the use of DES were identified: baseline heterogeneity, continuous disease markers, time varying event rates, and the influence of prior events on subsequent event rates. If relevant, individual-level data are available, representation of the four factors is likely to improve model validity, and it is possible to assess the importance of their representation in individual cases. A thorough model performance evaluation is required to overcome the costs of DES from the users' perspective, but few of the reviewed DES models reported such a process. More generally, further direct, empirical comparisons of complex models with simpler models would better inform the benefits of DES to implement more complex models, and the circumstances in which such benefits are most likely.

Estimating the potential annual welfare impact of innovative drugs in use in Switzerland

Expenditures of health care systems are increasing from year to year. Therefore, this study aimed to estimate the difference in costs and benefits of innovative pharmaceuticals launched 2000 onward compared to standard treatment on the national economy of Switzerland in 2010. The approach and formula described in the pilot study by Tsiachristas et al. (1), which analyzed the situation of welfare effects in the Netherlands, served as a model for our own calculations. A literature search was performed to identify cost-utility or cost-effectiveness studies of drugs launched 2000 onward compared to standard treatment. All parameters required for the calculation of welfare effects were derived from these analyses. The base-case threshold value of a quality-adjusted life year was set to CHF 100,000. Overall, 31 drugs were included in the welfare calculations. The introduction of innovative pharmaceuticals since 2000 onward to the Swiss market led to a potential welfare gain of about CHF 781 million in the year 2010. Univariate sensitivity analysis showed that results were robust. Probably because of the higher benefits of new drugs on health and quality of life compared to standard treatment, these drugs are worth the higher costs. The literature search revealed that there is a lack of information about the effects of innovative pharmaceuticals on the overall economy of Switzerland. Our study showed that potential welfare gains in 2010 by introducing innovative pharmaceuticals to the Swiss market were substantial. Considering costs and benefits of new drugs is important.

Review of models used in economic analyses of new oral treatments for type 2 diabetes mellitus

BACKGROUND

Economic models are considered to be important, as they help evaluate the long-term impact of diabetes treatment. To date, it appears that no article has reviewed and critically appraised the cost-effectiveness models developed to evaluate new oral treatments [glucagon-like peptide-1 (GLP-1) receptor agonists and dipeptidyl peptidase-4 (DPP-4) inhibitors] for type 2 diabetes mellitus (T2DM).

OBJECTIVES

This study aimed to provide insight into the utilization of cost-effectiveness modelling methods. The focus of our study was aimed at the applicability of these models, particularly around the major assumptions related to the clinical parameters (glycated haemoglobin [A1c], systolic blood pressure [SBP], lipids and weight) used in the models, and subsequent clinical outcomes.

METHODS

MEDLINE and EMBASE were searched from 1 January 2004 to 14 February 2013 in order to identify published cost-effectiveness evaluations for the treatment of T2DM by new oral treatments (GLP-1 receptor agonists and DPP-4 inhibitors). Once identified, the articles were reviewed and grouped together according to the type of model. The following data were captured for each study: comparators; country; evaluation and key cost drivers; time horizon; perspective; discounting rates; currency/year; cost-effectiveness threshold, sensitivity analysis; and cost-effectiveness analysis curves.

RESULTS

A total of 15 studies were identified in our review. Nearly all of the models utilized a health care payer perspective and provided a lifetime horizon. The CORE Diabetes Model, UK Prospective Diabetes Study (UKPDS) Outcomes Model, Cardiff Diabetes Model, Centers for Disease Control and Prevention (CDC) Diabetes Cost-Effectiveness Group Model and Diabetes Mellitus Model were cited. With the exception of two studies, all of the studies made significant assumptions surrounding the impact of GLP-1 receptor agonists or DPP-4 inhibitors on clinical parameters and subsequent short- and long-term outcomes. Moreover, often the differences in the clinical parameters were relatively small (e.g. 1 or 2 mmHg in blood pressure) and would not be considered by many as clinically important. Yet, the impact of these small clinical changes often resulted in large lifetime changes in health outcomes in the models. In particular, many studies assumed that changes in weight associated with the therapies would equate to improved outcomes, despite limited evidence for this assumption. Although the new oral treatments were regarded as cost effective in most studies based upon the studies reviewed, the validity of these projections, particularly for the longer time frames, is questionable. Indeed, although most of these studies have been conducted in the last 5 years, recent trial evidence has already questioned the validity of most of these studies.

CONCLUSION

It is clear that a number of changes are required in the evaluation of diabetes therapies. First and foremost, the basic models need to be updated to include contemporary important clinical trial data assessing hard clinical outcomes in patients with diabetes. Second, there should be less emphasis on 40-year or lifetime costs and consequences of the therapies and a greater focus on short-term (5-year) and intermediate-term (10-year) outcomes. Practice is continually evolving, and the probability that these models would provide any valid predictions beyond 10 years is remote. Third, all modellers should immediately remove the basic assumption that small clinically inconsequential changes in A1c, SBP, lipids and weight result in major clinical improvements in patients. Future models should aim to include all relevant treatment outcomes, whether these relate to effects on underlying diabetes and its complications or to short- or long-term side effects of treatment. We need to explore why cost-saving interventions could benefit further from adding patient characteristics, which may be able to better predict the use of lower-cost alternatives. Moreover, the vast array of different clinical, cost and utility data used in the different models reviewed makes it apparent that a uniform methodology should be developed for diabetes economic models. In this manner, future models could be run using the same data, which would allow for more acceptable comparability between studies.

The place of GLP-1-based therapy in diabetes management: differences between DPP-4 inhibitors and GLP-1 receptor agonists

Type 2 diabetes is a progressive disease characterized by the need for additional antidiabetic agents overtime to maintain a stable level of glycemic control. The discovery of the glucagon like peptide 1, 1 of the 2 major incretins, was pivotal to the development of novel therapies, which can be used in individuals with type 2 diabetes. Two classes of drugs, GLP-1 receptor agonists and dipeptidyl peptidase inhibitors, provide comparable or superior glycemic effects to previous antidiabetic agents without increasing side effects, such as weight gain and hypoglycemia. Therefore, they represent valuable additions to the current therapeutic options for type 2 diabetes.

Effect of addition of either sitagliptin or pioglitazone in patients with uncontrolled type 2 diabetes mellitus on metformin: A randomized controlled trial

OBJECTIVE

To compare and study the dipeptidy1 peptidase-4 (DPP-4) inhibitors in combination with metformin against established combination therapies.

MATERIALS AND METHODS

This 16-week study was designed to compare sitagliptin versus pioglitazone as add-on therapy in patients of type 2 diabetes mellitus inadequately controlled with metformin alone. Fifty-two patients were randomized into two groups to receive either sitagliptin 100 mg (group 1) or pioglitazone 30 mg (group 2) in addition to metformin. The primary efficacy end point was change in HbA1c. Secondary end points included change in fasting plasma glucose (FPG), body weight and lipid profile. Treatment satisfaction was assessed using the Diabetes Treatment Satisfaction Questionnaire. Both the groups had a significant decrease in HbA1c.

RESULTS

There was no significant difference between mean reductions in FPG in both the groups. There was a significant decrease in the mean body weight and body mass index in group 1 in contrast to the significant increase in the same in group 2. Both the treatment groups reported a significant decrease in High-density lipoprotein (HDL-C) and Triglyceride.

CONCLUSION

Sitagliptin was well tolerated without any incidence of hypoglycemia. It was concluded that sitagliptin as an add-on to metformin is as effective and well tolerated as pioglitazone.

Treatment of type 2 diabetes with saxagliptin: a pharmacoeconomic evaluation in Argentina

BACKGROUND

The increasing prevalence of diabetes and its inadequate management results in a heavy burden of the disease for the patients, the health and the productive system and the overall community. Consequently, it is necessary to have new effective drugs to treat people with diabetes to decrease such burden. DPP-4 inhibitors can help to cope with this demand, but its usage is challenged by its apparent high cost. The aim of the current study was to compare a simulated cost-effectiveness ratio of metformin (MET) plus one drug of the DPP-4 inhibitors family, saxagliptin (SAXA) or sulfonylurea (SU) treatment during a 20-year period, from the perspective of the social security system, in a cohort of people with Type 2 diabetes (T2DM) who did not attain glycosylated hemoglobin treatment target values only with MET.

METHODS

A discrete event simulation model (Cardiff diabetes model) based on UKPDS 68 was used to simulate disease progression and to estimate the economic and health treatment consequences in people with T2DM. The clinical efficacy parameters for SAXA administration were obtained from the literature; local standard costs were considered for drug acquisition, adverse events (AEs), and micro/macrovascular complications. Costs were expressed in US dollars (2009) with an annual 3.5% discount and a 20-year time horizon.

RESULTS

The SAXA + MET treated group had a lower number of non-fatal events than the SU + MET treated group. The model also predicted a lower number of fatal macrovascular events for the SAXA + MET group (149.6 vs. 152.8). The total cost of the SAXA + MET cohort was 15% higher than that of the SU + MET cohort. Treatment with SAXA + MET resulted in a higher number of quality-adjusted life years (QALYs) (9.54 vs. 9.32) and life-years gained (LYGs) (20.84 vs. 20.76) compared to those treated with SU + MET. The incremental cost per QALY and LYG gained was $7,374 and $20,490, respectively.

CONCLUSIONS

According to the criteria proposed by the Commission on Macroeconomics and Health, the use of the combination SAXA + MET is highly cost-effective in Argentina.

Inertia on hypoglycemia: highlight from a Taiwan subgroup analysis of Real-Life Effectiveness and Care Patterns of Diabetes Management (RECAP-DM) study

Type 2 diabetes mellitus is a global health issue. Patients with poor glycemic control often suffer from cardiovascular, cerebrovascular, neuropathic, and nephropathic complications as well as other chronic conditions. Therapeutic guidelines recommend that diabetic patients should maintain their HbA(1c) level below a certain target in order to minimize the risk of developing complications. However, hypoglycemia is recognized as a major impediment to the adequate control of type 2 diabetes. Hypoglycemia can manifest symptoms of varying degrees of severity. Moreover, an association between hypoglycemia and cardiovascular morbidity and mortality has been reported. Here, we present a post hoc Taiwan subgroup analysis of these data collected in the RECAP-DM study to indicate probably more emphasis and concern on hypoglycemia in type 2 diabetic patients in Taiwan. In this analysis, we found no significant difference was observed in treatment-related satisfaction between Taiwanese patients with or without hypoglycemia. Another finding of our study further shows that varying order of hypoglycemic symptoms or severity has no effect on patients' assessment of health-related quality of life scores. We need to pay more attention to this issue because of its enduring impact on compliance and concerns about hypoglycemia in type 2 diabetic patients. Nevertheless, socio-demographic characteristics are also important factors influencing glycemic control and patients' health-related quality of life. Future interventions and therapeutic algorithms should emphasize the probable patients' unawareness or neglect on hypoglycemia in diabetic patients.

Cost-effectiveness of saxagliptin (Onglyza®) in type 2 diabetes in Sweden

AIM

The objective of this study was to investigate the cost-effectiveness of saxagliptin (Onglyza(®)), a DPP-4 inhibitor, plus metformin compared with a sulphonylurea (SU) (Glipizide) plus metformin in Swedish patients not well controlled on metformin alone.

METHODS

Data from a 52-week clinical trial comparing saxagliptin and glipizide in combination with metformin was used in a simulation model to estimate long term complications in a cohort of type 2 diabetes patients. The model estimates the incidence of microvascular and macrovascular complications, diabetes-specific mortality, all-cause mortality, and ultimately, costs and quality-adjusted life years (QALYs) associated with the investigated treatment strategies. Costs and QALYs were estimated for a lifetime time horizon.

RESULTS

Compared with SU+metformin, the cost per QALY gained with saxagliptin+metformin is approximately SEK 91,000. Patients on saxagliptin+metformin gain 0.10 QALYs on average, at an incremental cost of around SEK 9500. The cost-effectiveness results were robust to various sensitivity analyses.

CONCLUSIONS

This study demonstrates that, over a patient's lifetime, the addition of saxagliptin to metformin is associated with improvements in quality-adjusted life years compared with SU in patients with type 2 diabetes. Saxagliptin treatment is a cost-effective treatment alternative for type 2 diabetes in patients not well-controlled on metformin alone.

Cost-utility analysis of liraglutide compared with sulphonylurea or sitagliptin, all as add-on to metformin monotherapy in Type 2 diabetes mellitus

AIM

To investigate the cost-effectiveness of liraglutide as add-on to metformin vs. glimepiride or sitagliptin in patients with Type 2 diabetes uncontrolled with first-line metformin.

METHODS

Data were sourced from a clinical trial comparing liraglutide vs. glimepiride, both in combination with metformin, and a clinical trial comparing liraglutide vs. sitagliptin, both as add-on to metformin. Only the subgroup of patients in whom liraglutide was added to metformin monotherapy was included in the cost-utility analysis. The CORE Diabetes Model was used to simulate outcomes and costs with liraglutide 1.2 and 1.8 mg vs. glimepiride and vs. sitagliptin over patients' lifetimes. Treatment effects were taken directly from the trials. Costs and outcomes were discounted at 3.5% per annum and costs were accounted from a third-party payer (UK National Health System) perspective.

RESULTS

Treatment with liraglutide 1.2 and 1.8 mg resulted, respectively, in mean increases in quality-adjusted life expectancy of 0.32 ± 0.15 and 0.28 ± 0.14 quality-adjusted life years vs. glimepiride, and 0.19 ± 0.15 and 0.31 ± 0.15 quality-adjusted life years vs. sitagliptin, and was associated with higher costs of £ 3003 ± £ 678 and £ 4688 ± £ 639 vs. glimepiride, and £ 1842 ± £ 751 and £ 3224 ± £ 683 vs. sitagliptin, over a patient's lifetime. Both liraglutide doses were cost-effective, with incremental cost-effectiveness ratios of £ 9449 and £ 16,501 per quality-adjusted life year gained vs. glimepiride, and £ 9851 and £ 10,465 per quality-adjusted life year gained vs. sitagliptin, respectively.

CONCLUSIONS

Liraglutide, added to metformin monotherapy, is a cost-effective option for the treatment of Type 2 diabetes in a UK setting.

Dipeptidyl peptidase-4 inhibitors and preservation of pancreatic islet-cell function: a critical appraisal of the evidence

Type 2 diabetes mellitus (T2DM) develops as a consequence of progressive β-cell dysfunction in the presence of insulin resistance. None of the currently-available T2DM therapies is able to change the course of the disease by halting the relentless decline in pancreatic islet cell function. Recently, dipeptidyl peptidase (DPP)-4 inhibitors, or incretin enhancers, have been introduced in the treatment of T2DM. This class of glucose-lowering agents enhances endogenous glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) levels by blocking the incretin-degrading enzyme DPP-4. DPP-4 inhibitors may restore the deranged islet-cell balance in T2DM, by stimulating meal-related insulin secretion and by decreasing postprandial glucagon levels. Moreover, in rodent studies, DPP-4 inhibitors demonstrated beneficial effects on (functional) β-cell mass and pancreatic insulin content. Studies in humans with T2DM have indicated improvement of islet-cell function, both in the fasted state and under postprandial conditions and these beneficial effects were sustained in studies with a duration up to 2 years. However, there is at present no evidence in humans to suggest that DPP-4 inhibitors have durable effects on β-cell function after cessation of therapy. Long-term, large-sized trials using an active blood glucose lowering comparator followed by a sufficiently long washout period after discontinuation of the study drug are needed to assess whether DPP-4 inhibitors may durably preserve pancreatic islet-cell function in patients with T2DM.

Long-term cost-effectiveness of insulin detemir versus NPH insulin in type 2 diabetes in Sweden

AIM

To evaluate the cost-effectiveness of insulin detemir vs. NPH insulin once daily, in patients with type 2 diabetes in the Swedish setting based on clinical data from a published randomized controlled trial.

METHODS

Projections of long-term outcomes were made using the IMS CORE Diabetes Model (CDM), based on clinical data from a 26-week randomized controlled trial that compared once daily insulin detemir and NPH insulin, when used to intensify insulin treatment in 271 patients with type 2 diabetes and body mass index (BMI) 25-40 kg/m(2). Trial results showed that insulin detemir was associated with a significantly lower incidence of hypoglycemic events and significantly less weight gain in comparison with NPH insulin. The analysis was conducted from a third party payer perspective and the base case analysis was performed over a time horizon of 40 years and future costs and clinical outcomes were discounted at a rate of 3% per year.

RESULTS

Insulin detemir was associated with higher mean (SD) quality-adjusted life expectancy (5.42 [0.10] vs. 5.31 [0.10] quality-adjusted life years [QALYs]) and lower overall costs (SEK 378,539 [10,372] vs. SEK 384,216 [11,230]; EUR 33,794 and EUR 34,300, respectively, where 1 EUR=11.2015 SEK) compared with NPH insulin. Sensitivity analysis showed that the principal driver of the benefits associated with insulin detemir was the lower rate of hypoglycemic events (major and minor events) vs. NPH insulin, suggesting that detemir might also be cost-saving over a shorter time horizon. Limitations of the analysis include the use of data from a trial outside Sweden in the Swedish setting.

CONCLUSIONS

Based on clinical input data derived from a previously published randomized controlled trial, it is likely that in the Swedish setting insulin detemir would be cost-saving in comparison with NPH insulin for the treatment of patients with type 2 diabetes.

DPP-4 inhibitors in the management of type 2 diabetes: a critical review of head-to-head trials

Dipeptidyl peptidase-4 (DPP-4) inhibitors offer new options for the management of type 2 diabetes. Direct comparisons with active glucose-lowering comparators in drug-naive patients have demonstrated that DPP-4 inhibitors exert slightly less pronounced HbA(1c) reduction than metformin (with the advantage of better gastrointestinal tolerability) and similar glucose-lowering effects as with a thiazolidinedione (TZD; with the advantage of no weight gain). In metformin-treated patients, gliptins were associated with similar HbA(1c) reductions compared with a sulphonylurea (SU; with the advantage of no weight gain, considerably fewer hypoglycaemic episodes and no need for titration) and a TZD (with the advantage of no weight gain and better overall tolerability). DPP-4 inhibitors also exert clinically relevant glucose-lowering effects compared with a placebo in patients treated with SU or TZD (of potential interest when metformin is either not tolerated or contraindicated), and as oral triple therapy with a good tolerability profile when added to a metformin-SU or pioglitazone-SU combination. Several clinical trials also showed a consistent reduction in HbA(1c) when DPP-4 inhibitors were added to basal insulin therapy, with no increased risk of hypoglycaemia. Because of the complex pathophysiology of type 2 diabetes and the complementary actions of glucose-lowering agents, initial combination of a DPP-4 inhibitor with either metformin or a glitazone may be applied in drug-naive patients, resulting in greater efficacy and similar safety compared with either drug as monotherapy. However, DPP-4 inhibitors were less effective than GLP-1 receptor agonists for reducing HbA(1c) and body weight, but offer the advantage of being easier to use (oral instead of injected administration) and lower in cost. Only one head-to-head trial demonstrated the non-inferiority of saxagliptin vs sitagliptin. Clearly, more trials of direct comparisons between different incretin-based therapies are needed. Because of their pharmacokinetic characteristics, pharmacodynamic properties (glucose-dependent glucose-lowering effect) and good overall tolerability profile, DPP-4 inhibitors may have a key role to play in patients with renal impairment and in the elderly. The role of DPP-4 inhibitors in the therapeutic armamentarium of type 2 diabetes is rapidly evolving as their potential strengths and weaknesses become better defined mainly through controlled clinical trials.

The cost-effectiveness of interventions in diabetes: a review of published economic evaluations in the UK setting, with an eye on the future

AIM

To synthesise key outcomes data from cost-effectiveness studies in diabetes, in the UK setting, and describe a narrative for the evidence-base, in order to understand the direction that future health economics research in this field could be heading.

METHODS

The peer-reviewed literature was searched at http://www.pubmed.com for health economics analyses in diabetes in the UK setting published between 1995 and 2008, using the keywords: "costs", "cost-effectiveness", "diabetes", "UK". Studies on screening for diabetes or prevention of diabetes were excluded, along with studies that looked purely at cost of diabetes treatment or monitoring.

RESULTS

There were over 350 hits on MEDLINE. A total of 23 articles were identified and reviewed. 18 studies were in type 2, two in type 1 and three studies in both types 1 and type 2 diabetes. All studies evaluated treatment from the perspective of the NHS, with the time horizons varying from 12 months to patient lifetimes. 13 studies estimated quality-adjusted life expectancy (QALE). The majority of studies used health economics modelling techniques to project clinical benefit and cost outcomes beyond the context of clinical trials, with Markov-type models predominating. The United Kingdom Prospective Study of Diabetes was the most frequently cited source of clinical effectiveness and cost data. Most studies were funded by the pharmaceutical industry and evaluated more expensive products, rather than cheaper generic therapies such as human insulin and metformin monotherapy.

CONCLUSION

Treatment-to-target in patients with diabetes in the UK is generally cost-effective and sometimes cost-saving vs. standard care. Ongoing health economics analysis in diabetes is essential as new clinical data are published. Future analysis of clinical and cost outcomes in diabetes could be expected to look beyond the impact of interventions on HbA1c in isolation, as manufacturers seek to differentiate innovative products in the market. Furthermore, it is anticipated that the competitiveness in the market for interventions in diabetes will lead to future cost-effectiveness analysis taking more interest in comparisons of off-patent medication and generic, fixed-dose combination therapies.

Pharmacokinetic and pharmacodynamic evaluation of sitagliptin plus metformin

IMPORTANCE OF THE FIELD

Type 2 diabetes is an increasingly prevalent disease resulting from various complex combinations of defects in insulin secretion and insulin action. Adequate blood glucose control is necessary to minimize complications. DPP IV inhibitors (sitagliptin, vildagliptin, saxagliptin) offer new options for combined pharmacological therapy.

AREAS COVERED IN THIS REVIEW

An extensive literature search was performed to analyze the potential pharmacokinetic (PK) and pharmacodynamic (PD) interactions between metformin (first-line drug for the management of type 2 diabetes) and sitagliptin (first commercialized DPP IV inhibitor). Metformin and sitagliptin may be administered together, either separately or in fixed-dose combination.

WHAT THE READER WILL GAIN

Updated information about PK/PD data on metformin alone, sitagliptin alone and sitagliptin plus metformin. Metformin and sitagliptin are not prone to PK drug-drug interactions. Their co-administration, either separately or in a fixed-dose combination, improves blood glucose control more potently than either compound separately, without hypoglycemia and without increasing metformin-related gastrointestinal side effects.

TAKE HOME MESSAGE

The combination sitagliptin plus metformin may be used as a first- or second-line therapy in the management of type 2 diabetes.

Weight Management in Overweight and Obese Patients with Type 2 Diabetes Mellitus

Obesity is recognised as an important risk factor for type 2 diabetes, inducing insulin resistance and pancreatic beta-cell dysfunction. These obesity-related defects tend to progress following weight gain and can eventually lead to worsening hyperglycaemia over time. Thus, effective weight management is crucial for glycaemic control in overweight and obese patients with type 2 diabetes. Current standard strategies for weight management in these patients include lifestyle interventions and pharmacotherapy. Bariatric surgery has become a promising new option for the treatment of obese patients with type 2 diabetes and in recent years incretin-based therapies have become available, which exhibit favourable effects on body weight. Herein, the efficacy of available weight loss interventions is assessed and the role of newer antidiabetic agents examined, focusing on incretin-based therapies.

Economic models in type 2 diabetes

OBJECTIVE

To identify and critically appraise cost-effectiveness models developed to evaluate type 2 diabetes (T2D) treatments and to assess which types of treatment effects they capture.

RESEARCH DESIGN AND METHODS

A systematic search was performed in MEDLINE, EMBASE, Centre for Reviews and Dissemination databases at the University of York, and Health Economic Evaluation Database for the period to September 2008. The websites of Health Technology Assessment (HTA) bodies in different countries were also screened for relevant models. For each of the identified original models, details of the structure, data in- and outputs were extracted and the overall quality of the model in terms of the combination of structure, assumptions and data inputs were appraised using published criteria.

RESULTS

Seventy-eight articles and 41 HTAs reporting relevant economic evaluations were identified. There were ten models with multiple publications, and a further ten models with one associated publication. The critical review demonstrated that most had the same fundamental structure, used similar micro-simulation techniques and were based on the same key data sources. However, the process for identification of relevant data and their synthesis, and the selection of outcomes lacked transparency. The models differed according to the extent and type of interventions they evaluated and which diabetes complications and treatment-related adverse events were captured. For example, just one model incorporated changes in patient weight, despite the fact that weight gain can be a side-effect of some treatments, and weight loss a potential benefit of others.

CONCLUSIONS

Whilst many economic models exist in T2D, most share common features such as the model type. Identified shortcomings are lack of transparency in data identification and evidence synthesis as well as the selection of the modelled outcomes. Future models should aim to include all relevant treatment outcomes, whether these relate to effects on underlying diabetes and its complications or to short- or long-term side effects of treatment.

Sitagliptin: a review of its use in the management of type 2 diabetes mellitus

Sitagliptin (Januvia, Glactiv(R), Tesavel(R)) is a dipeptidyl peptidase-4 inhibitor indicated for the treatment of type 2 diabetes mellitus. Oral sitagliptin as monotherapy or combination therapy was generally well tolerated and improved glycaemic control in well designed clinical trials in patients with type 2 diabetes. Glycosylated haemoglobin (HbA(1c)) levels were significantly reduced with sitagliptin monotherapy relative to voglibose monotherapy or placebo, and with sitagliptin as initial combination therapy with metformin or pioglitazone relative to monotherapy with these agents or placebo. Moreover, sitagliptin monotherapy was noninferior to metformin monotherapy in terms of the reduction in HbA(1c) levels. Significant reductions in HbA(1c) levels, relative to background therapy, were also observed with sitagliptin add-on therapy to ongoing treatment with thiazolidinediones, sulfonylureas or insulin with or without metformin, or metformin alone. In terms of the reduction in HbA(1c) levels as add-on treatment to metformin, sitagliptin was noninferior to glipizide and generally did not differ from rosiglitazone, and as add-on treatment to pioglitazone, it did not differ significantly from metformin. Sitagliptin had a low risk of hypoglycaemia (except when used in combination with agents that may be associated with hypoglycaemia, such as sulfonylureas or insulin) and was generally weight-neutral. Although additional comparative data and longer-term studies with glycaemic and clinical outcomes are required to definitively position sitagliptin relative to other antihyperglycaemic agents, current evidence suggests that it is a useful treatment option for patients with type 2 diabetes, with potential advantages including oral administration, a generally weight-neutral effect and a low risk of hypoglycaemia.