Clinical efficacy and cost-effectiveness of metformin in different patient populations: A narrative review of real-world evidence.

Over the past two decades, diabetes pharmacopoeia has flourished, with new drugs that, on top of their glucose-lowering efficacy, have been shown to protect the heart and the kidney. Despite these new opportunities, metformin retains a pivotal role among glucose-lowering agents. As one of the few available insulin sensitizers, metformin is an effective, safe, and overall well-tolerated drug backed by over 60 years of clinical experience, including evidence for potential benefits beyond glucose reduction across different ages, sexes, genetic backgrounds, geographical areas, and stages of disease. Although there is some discussion of whether metformin offers the most effective front-line option in newly diagnosed type 2 diabetes (T2D), it remains a natural companion to all other glucose-lowering agents. Furthermore, metformin comes at a very low cost and, as such, it has extremely high cost-effectiveness, particularly given the serious economic burden associated with diabetes complications. This financial advantage is particularly relevant in resource-constrained healthcare systems, where the affordability of metformin may be instrumental in implementing an effective treatment in an evergrowing number of individuals. We present here compelling real-world evidence in support of the clinical efficacy and cost-effectiveness of metformin across different patient populations, highlighting areas where more population-based studies are needed to further incorporate and consolidate its use in the pharmacological management of T2D.

Cost-effectiveness analysis of metformin versus insulin in the treatment of gestational diabetes mellitus.

OBJECTIVE: Although there have been many studies on gestational diabetes mellitus (GDM) treatment, there is still a knowledge gap regarding the comparative cost-effectiveness of metformin and insulin in the treatment phase. Existing studies have focused on treatment efficacy and drug safety, but relatively little has been explored regarding cost-effectiveness analysis. In particular, no comprehensive study has evaluated the cost-effectiveness of metformin and insulin for GDM treatment. Therefore, this study aimed to fill this knowledge gap by conducting a cost-effectiveness analysis of these two treatments for GDM. METHODS: A decision-analytic model was used to compare the cost-effectiveness of metformin and insulin in China. Probabilities, costs, and utilities were derived from the literature. The cost and quality-adjusted life years (QALYs) were calculated using the roll-back method. The strategy was considered cost-effective if the incremental cost-effectiveness ratio (ICER) was below the willingness-to-pay (WTP) threshold of ¥242,938 per QALY. Sensitivity analyses were also conducted to assess the robustness of the results. RESULTS: The roll-back analysis indicated that insulin was not cost-effective compared to metformin, resulting in increased costs and decreased QALYs, with a negative ICER. These findings suggested that metformin is a cost-effective option than insulin. Furthermore, the sensitivity analysis showed that the model was robust. CONCLUSIONS: Compared with insulin, metformin is a cost-effective treatment option for GDM.

Comparison of healthcare resource utilization and costs in patients with type 2 diabetes initiating dapagliflozin versus sitagliptin.

AIMS: To compare healthcare costs and utilization in patients with type 2 diabetes (T2D) who initiated dapagliflozin (DAPA) with costs and utilization in those who initiated sitagliptin (SITA) in a real-world setting. MATERIALS AND METHODS: This was a retrospective study of health plan enrollees in two US commercial claims databases or Medicare Part D. The study population comprised adult patients with T2D who initiated DAPA or SITA between January 1, 2014 and April 30, 2015. DAPA and SITA initiators were propensity-score-matched, and healthcare utilization and costs during the 1-year follow-up period were compared. Analyses were conducted separately for patients with evidence of oral antidiabetic drug (OAD) monotherapy use at baseline. RESULTS: A total of 2722 patients were included in each matched cohort. Follow-up unadjusted all-cause costs ($16 065 and $17 281; P = 0.135) and diabetes-related costs ($9697 and $9354; P = 0.539) were similar in the DAPA and SITA cohorts. Higher office and outpatient visit costs in the SITA group were offset by higher pharmacy costs in the DAPA group. In the subgroup of 1804 patients with OAD monotherapy use at baseline, patients in the SITA group had higher total all-cause costs compared with those in the DAPA group ($14 884 vs. $12 353; P = 0.026). CONCLUSION: Patients who initiated DAPA or SITA had similar all-cause and diabetes-related healthcare costs over 1 year of follow-up. In the subgroup of patients treated with OAD monotherapy at baseline (84% metformin monotherapy), those who initiated DAPA as add-on therapy had lower costs than patients who added SITA.

Cost Utility of Sodium-Glucose Cotransporter 2 Inhibitors in the Treatment of Metformin Monotherapy Failed Type 2 Diabetes Patients: A Systematic Review and Meta-Analysis.

OBJECTIVES: Type 2 diabetes mellitus (T2DM) and associated ailments are leading economic burdens to society. Sodium glucose cotransporter-2 (SGLT2) inhibitors are recent antidiabetic medications with beneficial clinical efficacy. This meta-analysis was conducted to quantitatively pool the incremental net benefit of SGLT2 inhibitors in T2DM patients who failed metformin monotherapy. METHODS: Relevant economic evaluation studies of T2DM patients were identified from PubMed, Scopus, ProQuest, the Cochrane Library, and the Tufts Cost-Effective Analysis Registry until June 2018. Studies were eligible if they studied T2DM patients who failed metformin monotherapy and assessed the cost-effectiveness/utility between SGLT2 inhibitors and other treatments. Details of the study characteristics, economic model inputs, costs, and outcomes were extracted. Risk of bias was assessed using the biases in economic studies (ECOBIAS) checklist. The incremental net benefit was calculated with monetary units adjusting for purchasing power parity for 2017 US dollars. This was then pooled across studies stratified by the country's level of income using a random-effect model if heterogeneity was present and with a fixed-effect model otherwise. Heterogeneity was assessed using the Q test and I2 statistic. RESULTS: A total of 13 studies with 22 comparisons, mainly from high-income countries, were eligible. Six and 4 studies compared SGLT2 with dipeptidyl peptidase-4 inhibitors (DPP4i) and sulfonylureas, respectively. The pooled incremental net benefits (95% confidence interval) for these corresponding comparisons were $164.95 (-$534.71 to $864.61; I2 = 0%) and $3675.09 ($1656.46-$5693.71; I2 = 85.4%), respectively. These results indicate that SGLT2s were cost-effective in comparison with sulfonylureas but not DPP4i. CONCLUSION: SGLT2s were cost-effective as compared with sulfonylureas but not DPP4i. Most of the evidence was from high-income countries with few comparative drug groups, and the results might not be representative of the actual global scenario. Further studies from middle and lower economies and other comparators are still required.

Cost-effectiveness analysis of metformin with enzalutamide in the metastatic castrate-resistant prostate cancer setting.

INTRODUCTION: Enzalutamide (Enza) is an effective treatment for metastatic castrate-resistant prostate cancer (mCPRC). However, Enza is not cost-effective (CE) at willingness to pay (WTP) thresholds from $0-$125 000/quality adjusted life years (QALYs) and is therefore a strain on valuable health care dollars. Metformin (Met) is inexpensive (~$8.00/month) and is thought to improve prostate cancer specific and overall survival compared to those not taking Met. We hypothesized that there must be an added effect Met could provide that would make Enza CE thereby alleviating this financial strain on government health care budgets. MATERIALS AND METHODS: We constructed a Markov model and performed a threshold analysis to narrow in on the added effect needed to make such a combination therapy cost-effective at various WTP thresholds. RESULTS: At a WTP threshold of $50 000/QALY Enza + Met is unlikely to be CE unless it increases Enza's efficacy by more than 30%. At a WTP threshold of $100 000, Enza + Met could be CE barring Met adds 18.73% to the efficacy of Enza. CONCLUSIONS: Enza + Met is unlikely to be CE at WTP thresholds less than $100 000/QALY; these results make sense because a therapy that is not CE at these WTP thresholds by itself is unlikely to be CE with an adjuvant therapy that keep a patient on such a treatment for even longer. Finally, our model suggests that the mCRPC setting is not the optimal place to trial adding Met as the relative costs are high and utility values low.

Economic evaluation of type 2 diabetes prevention programmes: Markov model of low- and high-intensity lifestyle programmes and metformin in participants with different categories of intermediate hyperglycaemia.

BACKGROUND: National guidance on preventing type 2 diabetes mellitus (T2DM) in the UK recommends low-intensity lifestyle interventions for individuals with intermediate categories of hyperglycaemia defined in terms of impaired fasting glucose (IFG) or 'at-risk' levels of HbA1c. In a recent systematic review of economic evaluations of such interventions, most studies had evaluated intensive trial-based lifestyle programmes in participants with impaired glucose tolerance (IGT). This study examines the costs and effects of different intensity lifestyle programmes and metformin in participants with different categories of intermediate hyperglycaemia. METHODS: We developed a decision tree and Markov model (50-year horizon) to compare four approaches, namely (1) a low-intensity lifestyle programme based on current NICE guidance, (2) a high-intensity lifestyle programme based on the US Diabetes Prevention Program, (3) metformin, and (4) no intervention, modelled for three different types of intermediate hyperglycaemia (IFG, IGT and HbA1c). A health system perspective was adopted and incremental analysis undertaken at an individual and population-wide level, taking England as a case study. RESULTS: Low-intensity lifestyle programmes were the most cost-effective (£44/QALY, £195/QALY and £186/QALY compared to no intervention in IGT, IFG and HbA1c, respectively). Intensive lifestyle interventions were also cost-effective compared to no intervention (£2775/QALY, £6820/QALY and £7376/QALY, respectively, in IGT, IFG and HbA1c). Metformin was cost-effective relative to no intervention (£5224/QALY, £6842/QALY and £372/QALY in IGT, IFG and HbA1c, respectively), but was only cost-effective relative to other treatments in participants identified with HbA1c. At a willingness-to-pay threshold of £20,000/QALY, low- and high-intensity lifestyle programmes were cost-effective 98%, 99% and 98% and 81%, 81% and 71% of the time in IGT, IFG and HbA1c, respectively. An England-wide programme for 50-59 year olds could reduce T2DM incidence by < 3.5% over 50 years and would cost 0.2-5.2% of the current diabetes budget for 2-9 years. DISCUSSION: This analysis suggests that current English national policy of low-intensity lifestyle programmes in participants with IFG or HbA1c will be cost-effective and have the most favourable budget impact, but will prevent only a fraction of cases of T2DM. Additional approaches to prevention need to be investigated urgently.

Trends in Diabetes Treatment and Monitoring among Medicare Beneficiaries.

BACKGROUND: Diabetes is a costly and common condition, but little is known about recent trends in diabetes management among Medicare beneficiaries. OBJECTIVE: To evaluate the use of diabetes medications and testing supplies among Medicare beneficiaries. DESIGN/SETTING: Retrospective cohort analysis of Medicare claims from 2007 to 2014. PARTICIPANTS: Traditional Medicare beneficiaries with a diagnosis of diabetes in the current or any prior year. MAIN MEASURES: We analyzed choices of first diabetes medication for those new to medication and patterns of adding medications. We also examined the use of testing supplies, use of statins and ACE inhibitors/angiotensin receptor blockers, and spending. KEY RESULTS: Diagnosed diabetes increased from 28.7% to 30.2% of beneficiaries from 2007 to 2014. The use of metformin as the most commonly prescribed first medication increased from 50.2% in 2007 to 70.2% in 2014, whereas long-acting sulfonylureas decreased from 16.6% to 8.2%. The use of thiazolidinediones fell considerably, while the use of new diabetes medication classes increased. Among patients prescribed insulin, long-acting insulin as the first choice increased substantially, from 38.9% to 56.8%, but short-acting or combination regimens remained common, particularly among older or sicker beneficiaries. Prescriptions of testing supplies for more than once-daily testing were also common. The mean total cost of diabetes medications per patient increased over the period due to the increasing use of high-cost drugs, particularly by those patients with costs above the 90th percentile of spending, although the median costs decreased for both medications and testing supplies. CONCLUSIONS: The use of metformin and long-acting insulin have increased substantially among elderly Medicare patients with diabetes, but a substantial subgroup continues to receive costly and complex treatment regimens.

Cost-effectiveness analysis of metformin+dipeptidyl peptidase-4 inhibitors compared to metformin+sulfonylureas for treatment of type 2 diabetes.

BACKGROUND: Patients with type 2 diabetes (T2D) typically use several drug treatments during their lifetime. There is a debate about the best second-line therapy after metformin monotherapy failure due to the increasing number of available antidiabetic drugs and the lack of comparative clinical trials of secondary treatment regimens. While prior research compared the cost-effectiveness of two alternative drugs, the literature assessing T2D treatment pathways is scarce. The purpose of this study was to evaluate the long-term cost-effectiveness of dipeptidyl peptidase-4 inhibitors (DPP-4i) compared to sulfonylureas (SU) as second-line therapy in combination with metformin in patients with T2D. METHODS: A Markov model was developed with four health states, 1 year cycle, and a 25-year time horizon. Clinical and cost data were collected from previous studies and other readily available secondary data sources. The incremental cost-effectiveness ratio (ICER) was estimated from the US third party payer perspective. Both, costs and outcomes, were discounted at a 3% annual discount rate. One way and probabilistic sensitivity analyses were performed to evaluate the impact of uncertainty on the base-case results. RESULTS: The discounted incremental cost of metformin+DPP-4i compared to metformin+SU was $11,849 and the incremental life-years gained were 0.61, resulting in an ICER of $19,420 per life-year gained for patients in the metformin+DPP-4i treatment pathway. The ICER estimated in the probabilistic sensitivity analysis was $19,980 per life-year gained. Sensitivity analyses showed that the results of the study were not sensitive to changes in the parameters used in base-case. CONCLUSIONS: The metformin+DPP-4i treatment pathway was cost-effective compared to metformin+SU as a long-term second-line therapy in the treatment of T2D from the US health care payer perspective. Study findings have the potential to provide clinicians and third party payers valuable evidence for the prescription and utilization of cost-effective second-line therapy after metformin monotherapy failure in the treatment of T2D.

Pharmacoeconomic evaluation of glimepiride combined with other drugs in the treatment of diabetes.

The goal of diabetic drug treatment is to stabilize the blood sugar for a long time to close to the normal level, to correct the metabolic disorder and eliminate the symptoms. At present, glimepiride has become commonly used drugs for the treatment of diabetes with obesity. Compared with metformin, acarbose and rosiglitazone, glimepiride has different mechanisms of drug action, clinical combination showed synergistic hypoglycemic effect, good clinical curative effect. So, we use three treatments to study as group A (glimepiride and metformin); group B (glimepiride and acarbose); Group C (glimepiride and rosiglitazone). From the analysis of drug economics, glimepiride and metformin scheme is better, has the lowest cost per unit cost effect. From the comparison of scheme is efficient, the best curative effect is rosiglitazone plus glimepiride, effective rate as 96.7%. At the same time, the drug can be rationally used to reduce the occurrence of some drug-induced diseases and adverse drug reactions.

Managing glycaemia in older people with type 2 diabetes: A retrospective, primary care-based cohort study, with economic assessment of patient outcomes.

AIMS: To describe the relative health and economic outcomes associated with different second-line therapeutic approaches to manage glycaemia in older type 2 diabetes patients requiring escalation from metformin monotherapy. MATERIALS AND METHODS: The Clinical Practice Research Datalink database was used to inform a retrospective observational cohort study of patients with type 2 diabetes treated with metformin monotherapy requiring escalation (addition or switch) to a second-line oral regimen from January 1, 2008 to December 31, 2014. Primary outcomes included time to first event (any event, myocardial infarction [MI], stroke, or composite of MI/stroke [major adverse cardiovascular event; MACE]) and total event rate. The health economic consequences associated with the choice of second-line treatment in older patients were assessed using the CORE Diabetes Model. RESULTS: A total of 10 484 patients were included; the majority escalated to second-line treatment with metformin + sulphonylurea (SU; 42%) or switched to SU monotherapy (28%). In multivariate adjusted analyses, total event rates for MACE with metformin + dipeptidyl peptidase-4 (DPP-4) inhibitor were significantly lower than with metformin + SU (0.61, 95% confidence interval [CI] 0.39-0.98), driven by a lower MI rate in the metformin + DPP-4 inhibitor group (0.52, 95% CI 0.27-0.99). Economic analyses estimated that metformin + DPP-4 inhibitor treatment was associated with the largest gain in health benefit, and cost-effectiveness ratios were favourable (<£30 000 per quality-adjusted life-year) for all second-line treatment scenarios. CONCLUSIONS: With respect to treatment choice, data from the present study support the notion of prescribing beyond metformin + SU, as alternative regimens have been shown to be associated with reduced outcomes risk and value for money.

The changing cost to prevent diabetes: A retrospective analysis of the Diabetes Prevention Program.

OBJECTIVES: Diabetes prevention interventions are poorly implemented. While health care costs generally increase, 2 factors affect the relative cost of diabetes prevention interventions: the declining cost of metformin (even without insurance) and the new recommendation for vitamin B12 monitoring during metformin treatment. The study's objective was to update the relative health system cost estimate of metformin for diabetes prevention by incorporating the current health system cost of metformin and the cost of addressing potential metformin-associated vitamin B12 deficiency. The study was designed to assess whether metformin with vitamin B12 supplementation is a cost-saving measure for diabetes prevention and for the updated cost estimate to be useful in assessing future implementation studies. METHODS: In 2012, the Diabetes Prevention Program Research Group published detailed per capita total direct health system costs for the Diabetes Prevention Program (DPP) and the Diabetes Prevention Program Outcomes Study (DPPOS). The present analysis incorporated the declining cost of metformin and the increasing cost of metformin monitoring into the detailed per capita health system costs found in the DPP and DPPOS. The updated costs were used to assess the total cost of metformin use for diabetes prevention relative to placebo and lifestyle intervention. RESULTS: The current health system cost to acquire metformin ranges from $0 to $72 per year. The estimated health system cost to address potential metformin-associated vitamin B12 deficiency is $28 per metformin-treated patient per year. The 10-year total health system cost for metformin in diabetes prevention can decrease by $329 or increase by $21 depending on the cost to acquire metformin. Compared with placebo, the unadjusted cost savings of metformin is generally maintained, although it may double or quadruple depending on how metformin is acquired by patients. Metformin with vitamin B12 supplementation remained less costly and less effective than lifestyle intervention. CONCLUSION: Metformin is generally more cost-saving for diabetes prevention than previously reported because of decreasing costs for patients to acquire metformin. The cost savings was increased despite increased management cost associated with addressing metformin-associated vitamin B12 deficiency.

Research on hospital drug cost control based on the perspective of pharmaceutical economy.

In recent years, the continuous growth of drug costs has become one of the hot issues of society. In this paper, by using principles and methods of pharmacoeconomics, we study on the management of drug cost control in hospital. Pharmacoeconomics involves the effective allocation and rational use of drug resources, and study the economic effect, that is to carry out the study of drug resources utilization efficiency. Through the analysis of the cost-benefit analysis of drug treatment, we could find the a more cost-effective treatment. Pharmacoeconomics can be applied to the clinical diagnosis and treatment, make reasonable prescription cost effect, it could provide patients with high economic efficiency of treatment, so that drug treatment to achieve the best results.

Adherence to Metformin, Statins, and ACE/ARBs Within the Diabetes Health Plan (DHP).

BACKGROUND: Reducing patient cost-sharing and engaging patients in disease management activities have been shown to increase uptake of evidence-based care. OBJECTIVE: To evaluate the effect of employer purchase of a disease-specific plan with reduced cost-sharing and disease management (the Diabetes Health Plan/DHP) on medication adherence among eligible employees and dependents. DESIGN: Employer-level "intent to treat" cohort study, including data from eligible employees and their dependents with diabetes, regardless of whether they were enrolled in the DHP. SETTING: Employers that contracted with a large national health plan administrator in 2009, 2010, and/or 2011. PARTICIPANTS: Ten employers that purchased the DHP and 191 employers that did not (controls). Inverse probability weighting (IPW) estimation was used to adjust for inter-group differences. INTERVENTION: The DHP includes free or low-cost medications and physician visits. Enrollment strategies and specific benefit designs are determined by the employer and vary in practice. DHP participants are notified up front that they must engage in their own health care (e.g., receiving diabetes-related screening) in order to remain enrolled. MAIN OUTCOME MEASURE: Mean employee adherence to metformin, statins, and ACE/ARBs at the employer level at one year post-DHP implementation, as measured by the proportion of days covered (PDC). RESULTS: Baseline adherence to the three medications was similar across DHP and control employers, ranging from 64 to 69 %. In the first year after DHP implementation, predicted employer-level adherence for metformin (+4.9 percentage points, p = 0.017), statins (+4.8, p = 0.019), and ACE/ARBs (+4.4, p = 0.02) was higher with DHP purchase. LIMITATIONS: Non-randomized, observational study. CONCLUSIONS: The Diabetes Health Plan, an innovative health plan that combines reduced cost-sharing and disease management with an up-front requirement of enrollee participation in his or her own health care, is associated with a modest improvement in medication adherence at 12 months.

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.

Regional variation in use of a new class of antidiabetic medication among medicare beneficiaries: the case of incretin mimetics.

BACKGROUND: When incretin mimetic (IM) medications were introduced in 2005, their effectiveness compared with other less-expensive second-line diabetes therapies was unknown, especially for older adults. Physicians likely had some uncertainty about the role of IMs in the diabetes treatment armamentarium. Regional variation in uptake of IMs may be a marker of such uncertainty. OBJECTIVE: To investigate the extent of regional variation in the use of IMs among beneficiaries and estimate the cost implications for Medicare. METHODS: This was a cross-sectional analysis of 2009-2010 claims data from a nationally representative sample of 238 499 Medicare Part D beneficiaries aged ≥65 years, who were continuously enrolled in fee-for-service Medicare and Part D and filled ≥1 antidiabetic prescription. Beneficiaries were assigned to 1 of 306 hospital-referral regions (HRRs) using ZIP codes. The main outcome was adjusted proportion of antidiabetic users in an HRR receiving an IM. RESULTS: Overall, 29 933 beneficiaries (12.6%) filled an IM prescription, including 26 939 (11.3%) for sitagliptin or saxagliptin and 3718 (1.6%) for exenatide or liraglutide. The adjusted proportion of beneficiaries using IMs varied more than 3-fold across HRRs, from 5th and 95th percentiles of 5.2% to 17.0%. Compared with non-IM users, IM users faced a 155% higher annual Part D plan ($1067 vs $418) and 144% higher patient ($369 vs $151) costs for antidiabetic prescriptions. CONCLUSION: Among older Part D beneficiaries using antidiabetic drugs, substantial regional variation exists in the use of IMs, not accounted for by sociodemographics and health status. IM use was associated with substantially greater costs for Part D plans and beneficiaries.

Cost saving analysis of prediabetes intervention modalities in comparison with inaction using Markov state transition model-A multiregional case study.

BACKGROUND: Prediabetes management is a priority for policymakers globally, to avoid/delay type 2 diabetes (T2D) and reduce severe, costly health consequences. Countries moving from low to middle income are most at risk from the T2D "epidemic" and may find implementing preventative measures challenging; yet prevention has largely been evaluated in developed countries. METHODS: Markov cohort simulations explored costs and benefits of various prediabetes management approaches, expressed as "savings" to the public health care system, for three countries with high prediabetes prevalence and contrasting economic status (Poland, Saudi Arabia, Vietnam). Two scenarios were compared up to 15 y: "inaction" (no prediabetes intervention) and "intervention" with metformin extended release (ER), intensive lifestyle change (ILC), ILC with metformin (ER), or ILC with metformin (ER) "titration." RESULTS: T2D was the highest-cost health state at all time horizons due to resource use, and inaction produced the highest T2D costs, ranging from 9% to 34% of total health care resource costs. All interventions reduced T2D versus inaction, the most effective being ILC + metformin (ER) "titration" (39% reduction at 5 y). Metformin (ER) was the only strategy that produced net saving across the time horizon; however, relative total health care system costs of other interventions vs inaction declined over time up to 15 y. Viet Nam was most sensitive to cost and parameter changes via a one-way sensitivity analysis. CONCLUSIONS: Metformin (ER) and lifestyle interventions for prediabetes offer promise for reducing T2D incidence. Metformin (ER) could reduce T2D patient numbers and health care costs, given concerns regarding adherence in the context of funding/reimbursement challenges for lifestyle interventions.

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.

Quantifying the impact of drug exposure misclassification due to restrictive drug coverage in administrative databases: a simulation cohort study.

OBJECTIVE: Drug exposure misclassification may occur in administrative databases when individuals obtain nonreimbursed drugs by paying "out-of-pocket" or via alternative drug coverage plans. We examined the apparent association between oral antidiabetic therapy and mortality by simulating the effects of restrictive drug coverage policies. METHODS: Population-based cohort study of 12,272 new patients using oral antidiabetic agents were identified using the administrative databases of Saskatchewan Health, 1991 to 1996. We randomly misclassified 0% [base case], 10%, 25%, and 50% of known patients taking metformin according to either overt drug exposure (e.g., metformin users switched to nonusers) or time of metformin initiation (e.g., delayed capture of exposure); thereby simulating the use of a "non-formulary" or "special authorization" policy, respectively. We also simulated an age-dependent coverage policy, mimicking a policy restricted to seniors. RESULTS: Metformin use was associated with lower mortality compared with sulfonylurea use in the base case (adjusted hazard ratio [aHR] 0.88, 95% confidence interval [CI] 0.78-0.99) and the nonformulary simulations. The special authorization simulations demonstrated, however, an increasing relative mortality hazard of metformin versus sulfonylurea exposure: aHR 0.96, 95% CI 0.96-0.97 and aHR 1.34, 95% CI 1.31-1.37, for 10% and 50% delays in coverage capture respectively when 50% of metformin users were misclassified. Age-dependent drug coverage had a variable impact on mortality risk compared with the base-case cohort; however, a new-user simulation with a 1-year washout revealed consistent results to the base-case analysis. CONCLUSION: Restrictive drug coverage policies may result in substantial drug exposure misclassification, potentially severely biasing the results of drug-outcome relationships using administrative databases.

Cost-utility analysis of liraglutide versus glimepiride as add-on to metformin in type 2 diabetes patients in China.

OBJECTIVES: The aim of this study was to evaluate the long-term cost-utility of liraglutide versus glimepiride as add-on therapy to metformin in patients with type 2 diabetes mellitus (T2DM), based on the results of clinical trial conducted in Asian population. METHODS: The validated UKPDS Outcomes Model was used to project life expectancy, quality adjusted life-years (QALYs), incidence of diabetes-related complication and cost of complications in patients receiving those regimens. Baseline cohort characteristics and treatment effects were derived from an Asian study. China-specific complication costs and utility score were taken from local studies. Patients' outcomes were modeled for 30 years and incremental cost-effectiveness ratios were calculated for liraglutide compared with glimepiride from the healthcare system perspective. Both future costs and clinical benefits were discounted at 3 percent. Sensitivity analyses were performed. RESULTS: Over a period of 30 years, compared with glimepiride, liraglutide 1.8 mg was associated with improvements in life expectancy (0.1 year) and quality adjusted life-year (0.168 QALY), and a reduced incidence of diabetes-related complications leading to an incremental cost-effectiveness ratio per QALY gained versus glimepiride of CNY 25,6871 (DEC 2010, 1 USD = 6.6227 CNY). CONCLUSIONS: Long-term projections indicated that liraglutide was associated with increased life expectancy, QALYs, and reduced complication incidences comparing with glimepiride. When the UK cost of liraglutide was discounted by 38 percent, liraglutide would be a cost-effective option in China from the healthcare system perspective using the 3X GDP/capita per QALY as the WTP threshold.