Cost effectiveness of saxagliptin and metformin versus sulfonylurea and metformin in the treatment of type 2 diabetes mellitus in Germany: a Cardiff diabetes model analysis

Adverse drug events in cost-effectiveness models of pharmacological interventions for diabetes, diabetic retinopathy, and diabetic macular edema: a scoping review

OBJECTIVE

The objective of this review was to examine the role of adverse drug events (ADEs) caused by pharmacological interventions in cost-effectiveness models for diabetes mellitus, diabetic retinopathy, and diabetic macular edema.

INTRODUCTION

Guidelines for economic evaluation recognize the importance of including ADEs in the analysis, but in practice, consideration of ADEs in cost-effectiveness models seem to be vague. Inadequate inclusion of these harmful outcomes affects the reliability of the results, and the information provided by economic evaluation could be misleading. Reviewing whether and how ADEs are incorporated in cost-effectiveness models is necessary to understand the current practices of economic evaluation.

INCLUSION CRITERIA

Studies included were published between 2011-2022 in English, representing cost-effectiveness analyses using modeling framework for pharmacological interventions in the treatment of diabetes mellitus, diabetic retinopathy, or diabetic macular edema. Other types of analyses and other types of conditions were excluded.

METHODS

The databases searched included MEDLINE (PubMed), CINAHL (EBSCOhost), Scopus, Web of Science Core Collection, and NHS Economic Evaluation Database. Gray literature was searched via the National Institute for Health and Care Excellence, European Network for Health Technology Assessment, the National Institute for Health and Care Research, and the International Network of Agencies for Health Technology Assessment. The search was conducted on January 1, 2023. Titles and abstracts were screened for inclusion by 2 independent reviewers. Full-text review was conducted by 3 independent reviewers. A data extraction form was used to extract and analyze the data. Results were presented in tabular format with a narrative summary, and discussed in the context of existing literature and guidelines.

RESULTS

A total of 242 reports were extracted and analyzed in this scoping review. For the included analyses, type 2 diabetes was the most common disease (86%) followed by type 1 diabetes (10%), diabetic macular edema (9%), and diabetic retinopathy (0.4%). The majority of the included analyses used a health care payer perspective (88%) and had a time horizon of 30 years or more (75%). The most common model type was a simulation model (57%), followed by a Markov simulation model (18%). Of the included cost-effectiveness analyses, 26% included ADEs in the modeling, and 13% of the analyses excluded them. Most of the analyses (61%) partly considered ADEs; that is, only 1 or 2 ADEs were included. No difference in overall inclusion of ADEs between the different conditions existed, but the models for diabetic retinopathy and diabetic macular edema more often omitted the ADE-related impact on quality of life compared with the models for diabetes mellitus. Most analyses included ADEs in the models as probabilities (55%) or as a submodel (40%), and the most common source for ADE incidences were clinical trials (65%).

CONCLUSIONS

The inclusion of ADEs in cost-effectiveness models is suboptimal. The ADE-related costs were better captured than the ADE-related impact on quality of life, which was most pronounced in the models for diabetic retinopathy and diabetic macular edema. Future research should investigate the potential impact of ADEs on the results, and identify the criteria and policies for practical inclusion of ADEs in economic evaluation.

SUPPLEMENTAL DIGITAL CONTENT

A Finnish-language version of the abstract of this review is available: http://links.lww.com/SRX/A68 .

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.

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.

The cost-effectiveness of dapagliflozin in treating high-risk patients with type 2 diabetes mellitus: An economic evaluation using data from the DECLARE-TIMI 58 trial

AIM

To undertake a cost-effectiveness analysis of dapagliflozin in treating high-risk patients with type 2 diabetes mellitus (T2DM), using both directly observed events in the DECLARE-TIMI 58 trial and surrogate risk factors to predict endpoints not captured within the trial.

METHODS

An established T2DM model was adapted to integrate survival curves derived from the DECLARE-TIMI 58 trial, and extrapolated over a lifetime for all-cause mortality, hospitalization for heart failure, stroke, myocardial infarction, hospitalization for unstable angina, and end-stage kidney disease. The economic analysis considered the overall DECLARE trial population, as well as reported patient subgroups. Total and incremental costs, life-years and quality-adjusted life-years associated with dapagliflozin versus placebo were estimated from the perspective of the UK healthcare payer.

RESULTS

In the UK setting, treatment with dapagliflozin compared to placebo was estimated to be dominant, with an expected increase in quality-adjusted life-years from 10.43 to 10.48 (+0.06) and a reduction in lifetime total costs from £39 451 to £36 899 (-£2552). Across all patient subgroups, dapagliflozin was estimated to be dominant, with the greatest absolute benefit in the prior heart failure subgroup (incremental lifetime costs -£4150 and quality-adjusted life-years +0.11).

CONCLUSIONS

The results of this study demonstrate that dapagliflozin compared to placebo appears to be cost-effective, when considering evidence reported from the DECLARE-TIMI 58 trial, at established UK willingness-to-pay thresholds. The findings highlight the potential of dapagliflozin to have a meaningful impact in reducing the economic burden of T2DM and its associated complications across a broad T2DM population.

Cost-Effectiveness of Saxagliptin Compared With Glibenclamide as a Second-Line Therapy Added to Metformin for Type 2 Diabetes Mellitus in Ethiopia

Background. Metformin is a widely accepted first-line pharmacotherapy for patients with type 2 diabetes mellitus (T2DM). Treatment of T2DM with glibenclamide, saxagliptin, or one of the other second-line treatment agents is recommended when the first-line treatment (metformin) cannot control the disease. However, there is little evidence on the additional cost and cost-effectiveness of adding second-line drugs. Therefore, this study aimed to estimate the cost-effectiveness of saxagliptin and glibenclamide as second-line therapies added to metformin compared with metformin only in T2DM in Ethiopia. Methods. This cost-effectiveness study was conducted in Ethiopia using a mix of primary data on cost and best available data from the literature on the effectiveness. We measured the interventions' cost from the providers' perspective in 2019 US dollars. We developed a Markov model for T2DM disease progression with five health states using TreeAge Pro 2020 software. Disability-adjusted life year (DALY) was the health outcome used in this study, and we calculated the incremental cost-effectiveness ratio (ICER) per DALY averted. Furthermore, one-way and probabilistic sensitivity analysis were performed. Results. The annual unit cost per patient was US$70 for metformin, US$75 for metformin + glibenclamide, and US$309 for metformin + saxagliptin. The ICER for saxagliptin + metformin was US$2259 per DALY averted. The ICER results were sensitive to various changes in cost, effectiveness, and transition probabilities. The ICER was driven primarily by the higher cost of saxagliptin relative to glibenclamide. Conclusion. Our study revealed that saxagliptin is not a cost-effective second-line therapy in patients with T2DM inadequately controlled by metformin monotherapy based on a gross domestic product per capita per DALY averted willingness-to-pay threshold in Ethiopia (US$953).

Quantitative Evidence Synthesis Methods for the Assessment of the Effectiveness of Treatment Sequences for Clinical and Economic Decision Making: A Review and Taxonomy of Simplifying Assumptions

Sequential use of alternative treatments for chronic conditions represents a complex intervention pathway; previous treatment and patient characteristics affect both the choice and effectiveness of subsequent treatments. This paper critically explores the methods for quantitative evidence synthesis of the effectiveness of sequential treatment options within a health technology assessment (HTA) or similar process. It covers methods for developing summary estimates of clinical effectiveness or the clinical inputs for the cost-effectiveness assessment and can encompass any disease condition. A comprehensive review of current approaches is presented, which considers meta-analytic methods for assessing the clinical effectiveness of treatment sequences and decision-analytic modelling approaches used to evaluate the effectiveness of treatment sequences. Estimating the effectiveness of a sequence of treatments is not straightforward or trivial and is severely hampered by the limitations of the evidence base. Randomised controlled trials (RCTs) of sequences were often absent or very limited. In the absence of sufficient RCTs of whole sequences, there is no single best way to evaluate treatment sequences; however, some approaches could be re-used or adapted, sharing ideas across different disease conditions. Each has advantages and disadvantages, and is influenced by the evidence available, extent of treatment sequences (number of treatment lines or permutations), and complexity of the decision problem. Due to the scarcity of data, modelling studies applied simplifying assumptions to data on discrete treatments. A taxonomy for all possible assumptions was developed, providing a unique resource to aid the critique of existing decision-analytic models.

Cost-utility analysis of second-line anti-diabetic therapy in patients with type 2 diabetes mellitus inadequately controlled on metformin

BACKGROUND

There are significant differences in costs and effectiveness among the second-line treatment options for type 2 diabetes (T2DM). We aimed to evaluate the cost-effectiveness of the second-line anti-diabetic therapy in T2DM patients inadequately controlled on metformin (MET) in Taiwan from the perspective of the National Health Insurance (NHI).

METHODS

The Cardiff T2DM model was used to predict the occurrence of mortality, diabetes-related complications, and drug adverse events. Five second-line treatments were selected for the analysis: sodium-glucose cotransporter 2 inhibitors (SGLT-2-i), glucagon-like peptide-1 receptor agonists (GLP-1-RA), dipeptidyl peptidase-4 inhibitor (DPP-4-i), sulfonylurea (SU), and insulin (INS). Treatment efficacy data were obtained from meta-analyses and randomized clinical trials, whereas cost data were derived from the NHI databases.

RESULTS

The analysis found that SU + MET (DPP-4-i as triple therapy) had the lowest cost, and SU + MET (SGLT-2-i as triple therapy) was associated with a mean incremental benefit of 0.47 quality-adjusted life years (QALYs) at an incremental cost of NT$2769, resulting in an incremental cost-effectiveness ratio (ICER) of NT$5840/QALY. Compared to their next less costly strategies, SGLT-2-i + MET (SU as triple therapy) and SGLT-2-i + MET (DPP-4-i as triple therapy) had ICER values of NT$63,170/QALY and NT$64,090/QALY, respectively. These results were fairly robust to extensive sensitivity analyses, but were relatively sensitive to baseline HbA1c, HbA1c threshold, and utilities.

CONCLUSION

The addition of either SU or SGLT-2-i to MET was found to be cost-effective, using the 2019 forecast for GDP per capita of Taiwan (NT$770,770) as the willingness to pay (WTP) threshold.

Management of Type 2 Diabetes in Developing Countries: Balancing Optimal Glycaemic Control and Outcomes with Affordability and Accessibility to Treatment

With the growing prevalence of type 2 diabetes, particularly in emerging countries, its management in the context of available resources should be considered. International guidelines, while comprehensive and scientifically valid, may not be appropriate for regions such as Asia, Latin America or Africa, where epidemiology, patient phenotypes, cultural conditions and socioeconomic status are different from America and Europe. Although glycaemic control and reduction of micro- and macrovascular outcomes remain essential aspects of treatment, access and cost are major limiting factors; therefore, a pragmatic approach is required in restricted-resource settings. Newer agents, such as sodium-glucose cotransporter 2 inhibitors and glucagon-like peptide 1 receptor agonists in particular, are relatively expensive, with limited availability despite potentially being valuable for patients with insulin resistance and cardiovascular complications. This review makes a case for the role of more accessible second-line treatments with long-established efficacy and affordability, such as sulfonylureas, in the management of type 2 diabetes, particularly in developing or restricted-resource countries.

A systematic review of economic evaluations in non-insulin antidiabetic treatments for patients with type 2 diabetes mellitus

The approval of new non-insulin treatments has broadened the therapeutic arsenal, but it has also increased the complexity of choice for the treatment of type 2 diabetes mellitus (DM2). The objective of this study was to systematically review the literature on economic evaluations associated with non-insulin antidiabetic drugs (NIADs) for DM2. We searched in Medline, IBECS, Doyma and SciELO databases for full economic evaluations of NIADs in adults with DM2 applied after the failure of the first line of pharmacological treatment, published between 2010 and 2017, focusing on studies that incorporated quality-adjusted life years (QALYs). The review included a total of 57 studies, in which 134 comparisons were made between NIADs. Under an acceptability threshold of 25,000 euros per QALY gained, iSLGT-2 were preferable to iDPP-4 and sulfonylureas in terms of incremental cost-utility. By contrast, there were no conclusive comparative results for the other two new NIAD groups (GLP-1 and iDPP-4). The heterogeneity of the studies’ methodologies and results hindered our ability to determine under what specific clinical assumptions some NIADs would be more cost-effective than others. Economic evaluations of healthcare should be used as part of the decision-making process, so multifactorial therapeutic management strategies should be established based on the patients’ clinical characteristics and preferences as principal criteria.

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.

Comparative effect of saxagliptin and glimepiride with a composite endpoint of adequate glycaemic control without hypoglycaemia and without weight gain in patients uncontrolled with metformin therapy: Results from the SPECIFY study, a 48-week, multi-centre, randomized, controlled trial

AIMS

To compare the efficacy and safety of saxagliptin and glimepiride in type 2 diabetes (T2D) patients who are inadequately controlled with metformin monotherapy.

MATERIALS AND METHODS

In this 48-week, multi-centre, open-label, randomized, parallel trial (NCT02280486, clinicaltrials.gov), a total of 388 T2D patients were randomized 1:1 to saxagliptin or glimepiride groups. The primary endpoint was achievement of HbA1c <7.0%, without hypoglycaemia, defined as blood glucose <3.9 mmol/L and weight gain <3.0% after 48 weeks of treatment.

RESULTS

Over 48 weeks, a greater proportion of patients achieved the primary endpoint with saxagliptin compared with glimepiride (43.3% vs 31.3%; odds ratio, 1.38, 95% CI, 1.05-1.82; P = 0.019), especially among patients with baseline HbA1c <8.0%, duration <5 years or baseline BMI ≥25 kg/m² . Mean reduction in HbA1c was similar in the two treatment groups at Week 48 (-0.94% with saxagliptin vs -0.98% with glimepiride; P = 0.439). Bodyweight decreased with saxagliptin, but increased with glimepiride over the treatment period, and the treatment difference was -1.6 kg (P < 0.001) at Week 48. The proportion of patients experiencing hypoglycaemia was much lower with saxagliptin vs glimepiride (3.1% vs 12.8%; P < 0.001).

CONCLUSIONS

This study provides evidence that, compared to glimepiride, saxagliptin more effectively achieves a composite endpoint of adequate glycaemic control without hypoglycaemia and without weight gain in T2D patients who are inadequately controlled with metformin monotherapy, especially in overweight patients with moderate hyperglycaemia and a relatively short duration of diabetes.

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.

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.

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.

How Consistent is the Relationship between Improved Glucose Control and Modelled Health Outcomes for People with Type 2 Diabetes Mellitus? a Systematic Review

BACKGROUND

There are an increasing number of studies using simulation models to conduct cost-effectiveness analyses for type 2 diabetes mellitus.

OBJECTIVE

To evaluate the relationship between improvements in glycosylated haemoglobin (HbA_1c) and simulated health outcomes in type 2 diabetes cost-effectiveness studies.

METHODS

A systematic review was conducted on MEDLINE and EMBASE to collect cost-effectiveness studies using type 2 diabetes simulation models that reported modelled health outcomes of blood glucose-related interventions in terms of quality-adjusted life-years (QALYs) or life expectancy (LE). The data extracted included information used to characterise the study cohort, the intervention's treatment effects on risk factors and model outcomes. Linear regressions were used to test the relationship between the difference in HbA_1c (∆HbA_1c) and incremental QALYs (∆QALYs) or LE (∆LE) of intervention and control groups. The ratio between the ∆QALYs and ∆LE was calculated and a scatterplot between the ratio and ∆HbA_1c was used to explore the relationship between these two.

RESULTS

Seventy-six studies were included in this research, contributing to 124 pair of comparators. The pooled regressions indicated that the marginal effect of a 1% HbA_1c decrease in intervention resulted in an increase in life-time QALYs and LE of 0.371 (95% confidence interval 0.286-0.456) and 0.642 (95% CI 0.494-0.790), respectively. No evidence of heterogeneity between models was found. An inverse exponential relationship was found and fitted between the ratio (∆QALY/∆LE) and ∆HbA_1c.

CONCLUSION

There is a consistent relationship between ∆HbA_1c and ∆QALYs or ∆LE in cost-effectiveness analyses using type 2 diabetes simulation models. This relationship can be used as a diagnostic tool for decision makers.

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.

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.

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.

The cost-effectiveness of dapagliflozin versus sulfonylurea as an add-on to metformin in the treatment of Type 2 diabetes mellitus

AIMS

To assess the cost-effectiveness of dapagliflozin, a sodium-glucose co-transporter-2 (SGLT-2) inhibitor, compared with a sulfonylurea, when added to metformin for treatment of UK people with Type 2 diabetes mellitus inadequately controlled on metformin alone.

METHODS

Clinical inputs sourced from a head-to-head randomized controlled trial (RCT) informed the Cardiff diabetes decision model. Risk equations developed from the United Kingdom Prospective Diabetes Study (UKPDS) were used in conjunction with the clinical inputs to predict disease progression and the incidence of micro- and macrovascular complications over a lifetime horizon. Cost and utility data were generated to present the incremental cost-effectiveness ratio (ICER) for both treatment arms, and sensitivity and scenario analyses were conducted to assess the impact of uncertainty on the final model results.

RESULTS

The dapagliflozin treatment arm was associated with a mean incremental benefit of 0.467 quality-adjusted life years (QALYs) [95% confidence interval (CI): 0.420; 0.665], with an incremental cost of £1246 (95% CI: £613; £1637). This resulted in an ICER point estimate of £2671 per QALY gained. Incremental costs were shown to be insensitive to parameter variation, with only treatment-related weight change having a significant impact on the incremental QALYs. Probabilistic sensitivity analysis determined that dapagliflozin had a 100% probability of being cost-effective at a willingness-to-pay threshold of £20,000 per QALY.

CONCLUSIONS

Dapagliflozin in combination with metformin was shown to be a cost-effective treatment option compared with sulfonylurea from a UK healthcare perspective for people with Type 2 diabetes mellitus who are inadequately controlled on metformin monotherapy.

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.

Comparison of diabetes-associated secondary healthcare utilization between alternative oral antihyperglycaemic dual therapy combinations with metformin in patients with type 2 diabetes: an observational cohort study

AIMS

To compare diabetes-associated secondary healthcare utilization in patients with type 2 diabetes (T2DM) prescribed sulphonylureas (SUs) versus other oral antihyperglycaemic agents (OHAs) as an add-on to metformin monotherapy (metformin + SU vs metformin + OHA).

METHODS

This retrospective cohort study used data from the Clinical Practice Research Datalink linked to Hospital Episode Statistics. Adults with T2DM initiated on metformin + SU or metformin + OHA from April 2003 to March 2012 were identified. Patients were matched using propensity scores. Diabetes-associated secondary healthcare visits were counted from >6 months post-initiation of dual therapy until treatment change or end of follow-up. Outcomes were calculated as rate ratios, adjusted for over-dispersion using negative binomial regression and propensity score for covariates.

RESULTS

After propensity score matching, 1704 patients were included in each cohort. For the primary objective (diabetes-associated inpatient and outpatient visits combined), the metformin + SU cohort had a directionally higher rate of diabetes-associated secondary healthcare utilization than the metformin + OHA cohort [adjusted rate ratio 1.12, 95% confidence interval (CI) 0.97-1.29]. For the secondary outcomes, the adjusted rate ratio was 1.38 (95% CI 0.95-2.00) for inpatient admissions and 1.10 (95% CI 0.95-1.28) for outpatient visits. Macrovascular complications, accounting for 77.2% of inpatient admissions, occurred at a statistically significantly higher rate in the metformin + SU cohort than in the metformin + OHA cohort (adjusted rate ratio 1.77, 95% CI 1.15-2.71).

CONCLUSIONS

This study found a statistically significant higher rate of inpatient admissions for macrovascular complications and cardiology outpatient visits and, overall, a directionally higher rate of secondary healthcare utilization for patients prescribed metformin + SU than for those prescribed metformin + OHA. This adds to the evidence that long-term and health economic outcomes should be considered in treatment decisions for 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-utility analysis of glucagon-like Peptide-1 agonists compared with dipeptidyl peptidase-4 inhibitors or neutral protamine hagedorn Basal insulin as add-on to metformin in type 2 diabetes in sweden

INTRODUCTION

This study aimed to assess the costs and benefits of three alternative second-line treatment strategies for Swedish patients with type 2 diabetes mellitus (T2DM) who fail to reach glycated hemoglobin (HbA1c) ≤ 7% with metformin treatment alone: glucagon-like peptide-1 (GLP-1) receptor agonists, dipeptidyl peptidase-4 (DPP-4) inhibitors, and neutral protamine Hagedorn (NPH) insulin.

METHODS

A previously developed cohort model for T2DM was applied over a 35-year time horizon. Data on T2DM patients on metformin monotherapy with HbA1c > 7% were collected from the Swedish National Diabetes Register. Treatment effects were taken from published studies. Costs and effects were discounted at 3% per annum, and the analysis was conducted from a societal perspective. The robustness of the results was evaluated using one-way and probabilistic sensitivity analyses.

RESULTS

Treatment with GLP-1 agonists was associated with a discounted incremental benefit of 0.10 and 0.25 quality-adjusted life years (QALYs) and higher discounted costs of Swedish Krona (SEK) 34,865 and SEK 40,802 compared with DPP-4 inhibitors and NPH insulin, respectively. Assuming willingness-to-pay (WTP) of SEK 500,000 per QALY, treatment strategy with GLP-1 agonists was a cost-effective option with incremental cost-effectiveness ratios of SEK 353,172 and SEK 160,618 per QALY gained versus DPP-4 inhibitors and NPH insulin, respectively. The results were most sensitive to incidence rate of moderate/major hypoglycemia and disutilities associated with insulin treatment, body mass index (BMI), and hypoglycemia.

CONCLUSION

Assuming a WTP of SEK 500,000 per QALY, treatment strategy with GLP-1 agonists is a cost-effective strategy in comparison to DPP-4 inhibitors and NPH insulin among T2DM patients inadequately controlled with metformin alone in a Swedish setting.

Cost effectiveness of adding dapagliflozin to insulin for the treatment of type 2 diabetes mellitus in the Netherlands

BACKGROUND AND OBJECTIVE

Many patients with type 2 diabetes mellitus (T2DM) on insulin therapy have inadequate glycaemic control. In such cases, Dutch guidelines recommend unlimited up-titration of insulin, yet in practice many patients never reach their glycaemic target. Clinical evidence shows that dapagliflozin-a highly selective sodium-glucose cotransporter 2 inhibitor-meets a need for these patients, i.e. by reducing glycated haemoglobin levels and bodyweight. We estimated the cost effectiveness and cost utility of adding dapagliflozin to insulin compared with not adding dapagliflozin in patients with T2DM who have inadequate glycaemic control while on insulin.

METHODS

The cost effectiveness of dapagliflozin was estimated using the Cardiff Diabetes Model, using direct comparative efficacy data from a randomized placebo-controlled trial (ClinicalTrials.gov identifier NCT00673231). In this trial, up-titration of insulin was allowed in case of severe glycaemic imbalance. Risk factor progression and the occurrence of future vascular events were estimated using the United Kingdom Prospective Diabetes Study 68 risk equations. Costs and utilities were derived from the literature. The analysis was conducted from the societal perspective, simulating the remaining lifetime of the patients.

RESULTS

The overall incidence of macro- and microvascular complications was lower, and life expectancy was greater (19.43 versus 19.35 life-years [LYs]) in patients receiving dapagliflozin than in those not receiving dapagliflozin. Patients in the dapagliflozin arm obtained an incremental benefit of 0.42 quality-adjusted life-years (QALYs). The lifetime incremental cost per patient in the dapagliflozin arm was €2,293, resulting in an incremental cost-effectiveness ratio of €27,779 per LY gained and an incremental cost-utility ratio of €5,502 per QALY gained. Sensitivity and scenario analyses showed that the results were insensitive to variations in modelling assumptions and input variables.

CONCLUSION

Dapagliflozin in combination with insulin was estimated to be a cost-effective treatment option for patients with T2DM whose insulin treatment regimen does not provide adequate glycaemic control in a Dutch healthcare setting.

Evidence-based practice use of incretin-based therapy in the natural history of diabetes

The incretin class of anti-hyperglycemic agents, including glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-inhibitors, is an important addition to the therapeutic armamentarium for the management of appropriate patients with type 2 diabetes mellitus as an adjunct to diet and exercise and/or with the agents metformin, sulfonylureas, thiazolidinediones, or any combination thereof. More recently, US Food and Drug Administration (FDA)-approved indications for incretins were expanded to include use with basal insulin. This review article takes an evidence-based practice approach in discussing the importance of aggressive treatment for diabetes, the principles of incretin physiology and pathophysiology, use of glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-4 inhibitors, and patient types and contexts where incretin therapy has been found beneficial, from metabolic syndrome to overt diabetes.

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.

Clinical utility in the treatment of type 2 diabetes with the saxagliptin/metformin fixed combination

Fixed-dose combination (FDC) products represent a widely accepted approach to type 2 diabetes treatment, given that monotherapies sometimes fail to meet the treatment targets - obtaining a sustained reduction in micro- and macrovascular complications. Saxagliptin (SAXA)/metformin (MET) FDC tablets can be used either alone or in combination with glyburide, thiazolidinediones, or insulin. It has been proven that the SAXA/MET combination leads to a significant improvement in glycemic control compared to placebo in patients with type 2 diabetes that is inadequately controlled with MET alone. In addition, this FDC has been proven to be safe for people with diabetes mellitus and established cardiovascular disease, elderly patients, and patients with impaired renal function (>30 mL/minute), with dosage modification. Patient compliance, adherence, and persistence to the therapeutic regimen has been shown to be very good, while the titration of each compound according to the patient's profile is easy, given the availability of different formulations. The SAXA/MET FDC is a patient-friendly, dosage-flexible, and hypoglycemia-safe regimen with very few adverse events and a neutral or even favorable effect on body weight. It achieves significant glycosylated hemoglobin A1c reduction helping the patient to achieve his/her individual glycemic goals.

Adding Saxagliptin to Metformin Extended Release (XR) or Uptitration of Metformin XR: Efficacy on Daily Glucose Measures

INTRODUCTION

Saxagliptin added to metformin extended release (XR) and uptitrated metformin XR were evaluated for their impact on daily glucose measurements and their tolerability in patients with type 2 diabetes mellitus (T2DM) inadequately controlled with metformin monotherapy.

METHODS

Patients aged 18-78 years on metformin 850-1,500 mg with glycated hemoglobin (HbA1c) 7.5-11.5% at screening were eligible for this double-blind, active-controlled study. Patients were stabilized on metformin XR 1,500 mg before randomization. Patients with HbA1c 7-11% and fasting plasma glucose (FPG) ≥126 mg/dL after a 4- 8-week lead-in period were randomly assigned to saxagliptin 5 mg + metformin XR 1,500 mg or metformin XR 500 mg + metformin XR 1,500 mg (uptitrated metformin XR). The primary end point was change from baseline to week 4 in 24-h mean weighted glucose (MWG). Secondary end points were changes from baseline to week 4 in 2-h postprandial glucose (PPG) and FPG.

RESULTS

At week 4, the adjusted mean ± SE change from baseline in 24-h MWG was -19.0 ± 5.7 mg/dL (95% CI -30.3 to -7.6) for saxagliptin + metformin XR and -8.2 ± 6.0 mg/dL (95% CI -20.0 to 3.7) for uptitrated metformin XR. Mean changes from baseline in 2-h PPG and FPG were numerically greater with saxagliptin + metformin XR versus uptitrated metformin XR. The incidence of adverse events was lower with saxagliptin + metformin XR (17.4%) versus uptitrated metformin XR (31.9%) mainly due to differences in gastrointestinal adverse event incidence (2.2% vs 10.6%, respectively). There were no reports of confirmed hypoglycemia in either group.

CONCLUSION

In this 4-week study in patients with T2DM inadequately controlled with metformin monotherapy, saxagliptin added to metformin XR demonstrated a trend for improvement in measures of daily glycemic control, with fewer gastrointestinal adverse events, compared with uptitrated metformin.

Simulated estimates of pre-pregnancy and gestational diabetes mellitus in the US: 1980 to 2008

PURPOSE

To simulate national estimates of prepregnancy and gestational diabetes mellitus (GDM) in non-Hispanic white (NHW) and non-Hispanic black (NHB) women.

METHODS

Prepregnancy diabetes and GDM were estimated as a function of age, race/ethnicity, and body mass index (BMI) using South Carolina live singleton births from 2004-2008. Diabetes risk was applied to a simulated population. Age, natality and BMI were assigned to women according to race- and age-specific US Census, Natality and National Health and Nutrition Examination Surveys (NHANES) data, respectively.

RESULTS

From 1980-2008, estimated GDM prevalence increased from 4.11% to 6.80% [2.68% (95% CI 2.58%-2.78%)] and from 3.96% to 6.43% [2.47% (95% CI 2.39%-2.55%)] in NHW and NHB women, respectively. In NHW women prepregnancy diabetes prevalence increased 0.90% (95% CI 0.85%-0.95%) from 0.95% in 1980 to 1.85% in 2008. In NHB women from 1980 through 2008 estimated prepregnancy diabetes prevalence increased 1.51% (95% CI 1.44%-1.57%), from 1.66% to 3.16%.

CONCLUSIONS

Racial disparities in diabetes prevalence during pregnancy appear to stem from a higher prevalence of prepregnancy diabetes, but not GDM, in NHB than NHW.

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.

Saxagliptin and Metformin in Fixed Combination for the Treatment of Type 2 Diabetes in Adults

Type 2 diabetes affects millions of people worldwide and significantly contributes to morbidity and mortality of those affected by it. Current guidelines recommend individualized treatment regimens following first line metformin therapy. Saxagliptin, a dipeptidyl-peptidase 4 inhibitor, provides a secondary mechanism of action to decrease hyperglycemia when used in combination with metformin. The combination of metformin and saxagliptin has shown improvements in hemoglobin A_1c and fasting plasma glucose in greater efficacy than when either agent is used alone. Adverse effects of combination therapy are similar to when these agents are used individually, and are rated as tolerable by patient satisfaction scores. Overall, the combination use of saxagliptin in addition to metformin is an attractive option for clinicians to use in the treatment of type 2 diabetes.