Cost-effectiveness of dipeptidyl peptidase-4 inhibitor monotherapy in elderly type 2 diabetes patients in Thailand

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.

Economic Evaluation of Type 2 Diabetes Mellitus Interventions in Low- and Middle-Income Countries: A Systematic Review of the Literature

The primary aim of this study is to assess the evidence on the cost-effectiveness of type 2 diabetes mellitus (T2DM) interventions with a focus on diabetes education, lifestyle modifications, surgical intervention, and pharmacological therapy in low- and middle-income countries (LMICs). A systematic review was conducted to identify economic evaluations of T2DM interventions published in LMICs for the period 2009-2019. A total of 25 studies were identified, with more than half of the studies being decision analytic models. Critical appraisal of the identified studies showed they were of good quality. Overall, the reported interventions in this review were very heterogeneous, which made them difficult to compare. However, there was strong evidence suggesting that diabetes education was a very cost-effective strategy in LMICs. Further evidence on affordability and budget impact of bariatric surgery is required before adopting the intervention. Metformin-based therapy showed promising evidence on cost-effectiveness and thus should be offered to T2DM patients in LMICs. On the contrary, the cost-effectiveness of lifestyle modifications remains understudied in LMICs. The findings in this review can inform policy guidance toward the inclusion of T2DM interventions in the benefit packages for Universal Health Coverage in LMICs.

Efficacy of vildagliptin on 10-year cardiovascular risk reduction in Thai patients with type 2 diabetes mellitus: A real-world observational study

BACKGROUND AND AIMS

This study aimed to assess the effects of vildagliptin on the prevention of cardiovascular diseases in Thai patients with type 2 diabetes mellitus using the Thai Cardiovascular Risk Score.

METHODS

All patients with type 2 diabetes mellitus who used vildagliptin at a secondary hospital in Thailand were screened and recruited. The relevant variables were obtained from patient medication charts at the first visit on which the patients were prescribed vildagliptin and from the 6-month, 12-month, and 18-month post-treatment visits. The Thai Cardiovascular Risk Score was calculated and monitored as a primary outcome, whereas changes in separate cardiometabolic parameters were assessed as secondary outcomes.

RESULTS

Of the 321 patients screened, only 95 were recruited for the analysis. The average 10-year cardiovascular risks of patients increased from 19.65% at baseline to 20.74%, 20.69%, and 23.78% at 6, 12, and 18 months post treatment, respectively. However, a better trend of reduction in cardiovascular risk was observed in patients with a high baseline cardiovascular risk. The glucose-lowering effects of vildagliptin were significantly observed 12 months of treatment onwards, but non-significant changes were found in lipid and blood pressure levels as well as body mass index.

CONCLUSION

Vildagliptin provided a promising glucose-lowering effect in Thai patients with type 2 diabetes mellitus. However, the mean 10-year cardiovascular risk did not significantly decrease. However, a negative correlation between cardiovascular risk reduction and baseline cardiovascular risk was observed in this study. Low sample size was a major limitation of this study.

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 validity of cost-effectiveness analyses of tight glycemic control. A systematic survey of economic evaluations of pharmacological interventions in patients with type 2 diabetes

PURPOSE

Currently available randomized trial evidence has shown no reductions in type 2 diabetes (T2D) complications important to patients with tight glycemic control. Yet, economic analyses consistently find tight glycemic control to be cost-effective. To understand this apparent paradox, we systematically identified and appraised economic analyses of tight glycemic control for T2D.

METHODS

We searched multiple databases from January 2016 to January 2018 for cost-effectiveness or cost-utility analyses of any glucose-lowering treatments for adults with T2D using simulations with long-40 years to lifetime-time horizons. Reviewers selected and appraised each study independently and in duplicate with good reproducibility.

RESULTS

We found 30 analyses, most comparing the glycemic impact of glucose-lowering drugs and applying their impact on HbA1c to model (most commonly IMS CORE or Cardiff T2DM) their impact on the incidence of diabetes-related complication. Models drew from observational evidence of the correlation of HbA1c levels and diabetes-related complication rates; none used estimates of the effect of lowering HbA1c on these outcomes from systematic reviews of randomized trials. Sensitivity analyses, when conducted, demonstrate substantial loss of cost-effectiveness as simulations approach the results seen in these trials.

CONCLUSIONS

Reliance on the association between glycemic control and diabetes-related complications evident in observational studies but not apparent in randomized trial bias the estimates of the cost-effectiveness of interventions to improve glycemic control.

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.

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.