Cost-effectiveness of acarbose for the management of impaired glucose tolerance in Sweden

Comparison of medical resources and costs among patients with coronary heart disease and impaired glucose tolerance in the Acarbose Cardiovascular Evaluation trial

BACKGROUND

The Acarbose Cardiovascular Evaluation (ACE) trial (ISRCTN91899513) evaluated the alpha-glucosidase inhibitor acarbose, compared with placebo, in 6522 patients with coronary heart disease and impaired glucose tolerance in China and showed a reduced incidence of diabetes. We assessed the within-trial medical resource use and costs, and quality-adjusted life years (QALYs).

METHODS

Resource use data were collected prospectively within the ACE trial. Hospitalizations, medications, and outpatient visits were valued using Chinese unit costs. Medication use was measured in drug days, with cardiovascular and diabetes drugs summed across the trial by participant. Health-related quality of life was captured using the EuroQol-5 Dimension-3 Level questionnaire. Regression analyses were used to compare resource use, costs, and QALYs, accounting for regional variation. Costs and QALYs were discounted at 3% yearly.

RESULTS

Hospitalizations were 6% higher in the acarbose arm during the trial (rate ratio 1.06, p = .009), but there were no significant differences in total inpatient days (rate ratio 1.04, p = .30). Total costs per participant, including study drug, were significantly higher for acarbose (¥ [Yuan] 56 480, £6213), compared with placebo (¥48 079, £5289; mean ratio 1.18, p < 0.001). QALYs reported by participants in the acarbose arm (3.96 QALYs) were marginally higher than in the placebo arm (3.95 QALYs), but the difference was not statistically significant (0.01 QALYs; p = .58).

CONCLUSIONS

Acarbose, compared with placebo, participants cost more due to study drug costs and reported no statistically significant difference in QALYs. These higher within-trial costs could potentially be offset in future by savings from the acarbose-related lower incidence of diabetes.

Benchmarking the Cost-Effectiveness of Interventions Delaying Diabetes: A Simulation Study Based on NAVIGATOR Data

OBJECTIVE

To estimate using the UK Prospective Diabetes Study Outcomes Model Version 2 (UKPDS-OM2) the impact of delaying type 2 diabetes onset on costs and quality-adjusted life expectancy using trial participants who developed diabetes in the NAVIGATOR (Nateglinide And Valsartan in Impaired Glucose Tolerance Outcomes Research) study.

RESEARCH DESIGN AND METHODS

We simulated the impact of delaying diabetes onset by 1-9 years, utilizing data from the 3,058 of 9,306 NAVIGATOR trial participants who developed type 2 diabetes. Costs and utility weights associated with diabetes and diabetes-related complications were obtained for the U.S. and U.K. settings, with costs expressed in 2017 values. We estimated discounted lifetime costs and quality-adjusted life years (QALYs) with 95% CIs.

RESULTS

Gains in QALYs increased from 0.02 (U.S. setting, 95% CI 0.01, 0.03) to 0.15 (U.S. setting, 95% CI 0.10, 0.21) as the imposed time to diabetes onset was increased from 1 to 9 years, respectively. Savings in complication costs increased from $1,388 (95% CI $1,092, $1,669) for a 1-year delay to $8,437 (95% CI $6,611, $10,197) for a delay of 9 years. Interventions costing up to $567-$2,680 and £201-£947 per year would be cost-effective at $100,000 per QALY and £20,000 per QALY thresholds in the U.S. and U.K., respectively, as the modeled delay in diabetes onset was increased from 1 to 9 years.

CONCLUSIONS

Simulating a hypothetical diabetes-delaying intervention provides guidance concerning the maximum cost and minimum delay in diabetes onset needed to be cost-effective. These results can inform the ongoing debate about diabetes prevention strategies and the design of future intervention studies.

Alpha-glucosidase inhibitors for prevention or delay of type 2 diabetes mellitus and its associated complications in people at increased risk of developing type 2 diabetes mellitus

BACKGROUND

Alpha-glucosidase inhibitors (AGI) reduce blood glucose levels and may thus prevent or delay type 2 diabetes mellitus (T2DM) and its associated complications in people at risk of developing of T2DM.

OBJECTIVES

To assess the effects of AGI in people with impaired glucose tolerance (IGT), impaired fasting blood glucose (IFG), moderately elevated glycosylated haemoglobin A1c (HbA1c) or any combination of these.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, ClinicalTrials.gov, the World Health Organization International Clinical Trials Registry Platform, and the reference lists of systematic reviews, articles and health technology assessment reports. The date of the last search of all databases was December 2017.

SELECTION CRITERIA

We included randomised controlled trials (RCTs), with a duration of one year or more, comparing AGI with any pharmacological glucose-lowering intervention, behaviour-changing intervention, placebo or no intervention in people with IFG, IGT, moderately elevated HbA1c or combinations of these.

DATA COLLECTION AND ANALYSIS

Two review authors read all abstracts and full-text articles or records, assessed quality and extracted outcome data independently. One review author extracted data, which were checked by a second review author. We resolved discrepancies by consensus or involvement of a third review author. For meta-analyses we used a random-effects model with assessment of risk ratios (RRs) for dichotomous outcomes and mean differences (MDs) for continuous outcomes, using 95% confidence intervals (CIs) for effect estimates. We assessed the overall quality of the evidence by using the GRADE instrument.

MAIN RESULTS

For this update of the Cochrane Review (first published 2006, Issue 4) we included 10 RCTs (11,814 participants), eight investigating acarbose and two investigating voglibose, that included people with IGT or people "at increased risk for diabetes". The trial duration ranged from one to six years. Most trials compared AGI with placebo (N = 4) or no intervention (N = 4).Acarbose reduced the incidence of T2DM compared to placebo: 670 out of 4014 people (16.7%) in the acarbose groups developed T2DM, compared to 812 out of 3994 people (20.3%) in the placebo groups (RR 0.82, 95% CI 0.75 to 0.89; P < 0.0001; 3 trials; 8008 participants; moderate-certainty evidence). One trial including participants with coronary heart disease and IGT contributed 64% of cases for this outcome. Acarbose reduced the risk of T2DM compared to no intervention: 7 out 75 people (9.3%) in the acarbose groups developed T2DM, compared to 18 out of 65 people (27.7%) in the no-intervention groups (RR 0.31, 95% CI 0.14 to 0.69; P = 0.004; 2 trials; 140 participants; very low-certainty evidence).Acarbose compared to placebo did not reduce or increase the risk of all-cause mortality (RR 0.98, 95% CI 0.82 to 1.18; P = 0.86; 3 trials; 8069 participants; very low-certainty evidence), cardiovascular mortality (RR 0.88; 95% CI 0.71 to 1.10; P = 0.26; 3 trials; 8069 participants; very low-certainty evidence), serious adverse events (RR 1.12, 95% CI 0.97 to 1.29; P = 0.13; 2 trials; 6625 participants; low-certainty evidence), non-fatal stroke (RR 0.50, 95% CI 0.09 to 2.74; P = 0.43; 1 trial; 1368 participants; very low-certainty evidence) or congestive heart failure (RR of 0.87; 95% CI 0.63 to 1.12; P = 0.40; 2 trials; 7890 participants; low-certainty evidence). Acarbose compared to placebo reduced non-fatal myocardial infarction: one out of 742 participants (0.1%) in the acarbose groups had a non-fatal myocardial infarction compared to 15 out of 744 participants (2%) in the placebo groups (RR 0.10, 95% CI 0.02 to 0.53; P = 0.007; 2 trials; 1486 participants; very low-certainty evidence). Acarbose treatment showed an increased risk of non-serious adverse events (mainly gastro-intestinal events), compared to placebo: 751 of 775 people (96.9%) in the acarbose groups experienced an event, compared to 723 of 775 people (93.3%) in the placebo groups (RR 1.04; 95% CI 1.01 to 1.06; P = 0.0008; 2 trials; 1550 participants). Acarbose compared to no intervention showed no advantage or disadvantage for any of these outcome measures (very low-certainty evidence).One trial each compared voglibose with placebo (1780 participants) or diet and exercise (870 participants). Voglibose compared to placebo reduced the incidence of T2DM: 50 out of 897 participants (5.6%) developed T2DM, compared to 106 out of 881 participants (12%) in the placebo group (RR 0.46, 95% CI 0.34 to 0.64; P < 0.0001; 1 trial; 1778 participants; low-certainty evidence). For all other reported outcome measures there were no clear differences between voglibose and comparator groups. One trial with 90 participants compared acarbose with diet and exercise and another trial with 98 participants reported data on acarbose versus metformin. There were no clear differences for any outcome measure between these two acarbose interventions and the associated comparator groups.None of the trials reported amputation of lower extremity, blindness or severe vision loss, end-stage renal disease, health-related quality of life, time to progression to T2DM, or socioeconomic effects.

AUTHORS' CONCLUSIONS

AGI may prevent or delay the development of T2DM in people with IGT. There is no firm evidence that AGI have a beneficial effect on cardiovascular mortality or cardiovascular events.

Screening for type 2 diabetes and dysglycemia

Type 2 diabetes mellitus (T2DM) and dysglycemia (impaired glucose tolerance and/or impaired fasting glucose) are increasingly contributing to the global burden of diseases. The authors reviewed the published literature to critically evaluate the evidence on screening for both conditions and to identify the gaps in current understanding. Acceptable, relatively simple, and accurate tools can be used to screen for both T2DM and dysglycemia. Lifestyle modification and/or medication (e.g., metformin) are cost-effective in reducing the incidence of T2DM. However, their application is not yet routine practice. It is unclear whether diabetes-prevention strategies, which influence cardiovascular risk favorably, will also prevent diabetic vascular complications. Cardioprotective therapies, which are cost-effective in preventing complications in conventionally diagnosed T2DM, can be used in screen-detected diabetes, but the magnitude of their effects is unknown. Economic modeling suggests that screening for both T2DM and dysglycemia may be cost-effective, although empirical data on tangible benefits in preventing complications or death are lacking. Screening for T2DM is psychologically unharmful, but the specific impact of attributing the label of dysglycemia remains uncertain. Addressing these gaps will inform the development of a screening policy for T2DM and dysglycemia within a holistic diabetes prevention and control framework combining secondary and high-risk primary prevention strategies.

Should the metabolic syndrome patient with prediabetes be offered pharmacotherapy?

Impaired fasting glucose and impaired glucose tolerance reflect perturbations in glucose metabolism and define a prediabetic state in which risk for type 2 diabetes mellitus (T2DM) is increased. There is overlap between prediabetes and the metabolic syndrome, which itself increases the risk for T2DM and cardiovascular disease. The utility of medical interventions to prevent progression to diabetes in prediabetic individuals, many of whom also manifest metabolic syndrome, has been examined in several large clinical trials. Intensive lifestyle intervention consistently results in drastic reductions in the incidence of T2DM and reversal of metabolic syndrome. Additionally, pharmacotherapies-including metformin, acarbose, thiazolidinediones, glucagon-like peptide 1 receptor agonists, and renin-angiotensin inhibitors-also reduce diabetes incidence with variable effects on metabolic syndrome components. Taken together, we recommend that prediabetic patients undergo intensive lifestyle intervention, with the addition of pharmacotherapy based on the presence of specific features of the metabolic syndrome, for diabetes prevention.

Prevention of Type 2 diabetes: fact or fiction?

The growing prevalence of Type 2 diabetes with its high morbidity and excess mortality is imposing a heavy burden on healthcare systems. Because of the magnitude of the problem, obviating diabetes has been a long-standing dream. In the last decade, a number of intervention strategies have been shown to be effective for the prevention of diabetes in high-risk populations with prediabetes. Seven studies have now confirmed that lifestyle modifications, including weight-reducing diets and exercise programs, are very effective in precluding or delaying Type 2 diabetes in high-risk populations with impaired glucose tolerance (IGT). Two major trials are the Diabetes Prevention Study (n = 522) from Finland and the Diabetes Prevention Program (n = 3234) from the US. Both studies have shown that intensive lifestyle intervention could reduce the progression of IGT to diabetes by 58%. Furthermore, four currently-available drugs have been established as being effective in preventing diabetes in subjects with prediabetes. The Diabetes Prevention Program revealed that metformin 850 mg b.i.d. reduced the risk of diabetes by 31%. The STOP-NIDDM (Study To Prevent Non-Insulin-Dependent Diabetes Mellitus) trial (n = 1429) showed that acarbose 100 mg t.i.d. with meals decreased the incidence of diabetes by 36% when the diagnosis was based on 2 oral glucose tolerance tests. The XENDOS (Xenical in the Prevention of Diabetes in Obese Subjects) study examined the use of orlistat, an antiobesity drug, as an adjunct to an intensive lifestyle modification program in obese non-diabetic subjects. Orlistat treatment resulted in a 37% decline in the development of diabetes. More recently, the DREAM (Diabetes Reduction Assessment with Ramipril and Rosiglitazone Medication) study (n = 5269) demonstrated that rosiglitazone at 8 mg once/day in subjects with prediabetes (IGT and/or impaired fasting glucose) was effective in reducing the risk of diabetes by 60%. It can be concluded that Type 2 diabetes can be prevented or delayed through lifestyle modifications and/or pharmacologic interventions. This is a fact.

Cost-effectiveness of screening for pre-diabetes among overweight and obese U.S. adults

OBJECTIVE

To estimate the cost-effectiveness of screening overweight and obese individuals for pre-diabetes and then modifying their lifestyle based on the Diabetes Prevention Program (DPP).

RESEARCH DESIGN AND METHODS

A Markov simulation model was used to estimate disease progression, costs, and quality of life. Cost-effectiveness was evaluated from a health care system perspective. We considered two screening/treatment strategies for pre-diabetes. Strategy 1 included screening overweight subjects and giving them the lifestyle intervention included in the DPP if they were diagnosed with both impaired glucose tolerance (IGT) and impaired fasting glucose (IFG). Strategy 2 included screening followed by lifestyle intervention for subjects diagnosed with either IGT or IFG or both. Each strategy was compared with a program of no screening.

RESULTS

Screening for pre-diabetes and treating those identified as having both IGT and IFG with the DPP lifestyle intervention had a cost-effectiveness ratio of $8,181 per quality-adjusted life-year (QALY) relative to no screening. If treatment was also provided to subjects with only IGT or only IFG (strategy 2), the cost-effectiveness ratio increased to $9,511 per QALY. Changes in screening-related parameters had small effects on the cost-effectiveness ratios; the results were more sensitive to changes in intervention-related parameters.

CONCLUSIONS

Screening for pre-diabetes in the overweight and obese U.S. population followed by the DPP lifestyle intervention has a relatively attractive cost-effectiveness ratio.

Alpha-glucosidase inhibitors for people with impaired glucose tolerance or impaired fasting blood glucose

BACKGROUND

Alpha-glucosidase inhibitors (AGIs) reduce blood glucose levels and may thus prevent type 2 diabetes and cardiovascular disease in patients with impaired glucose tolerance. These possible effects, and the effects on quality of life, plasma lipids and body weight, have never been investigated in a systematic literature review and meta-analysis.

OBJECTIVES

To assess the effects of alpha-glucosidase inhibitors in patients with impaired glucose tolerance (IGT) or impaired fasting blood glucose (IFBG), or both.

SEARCH STRATEGY

We searched The Cochrane Library (Clinical Trials database, formerly known as CENTRAL), PUBMED, EMBASE, Web of Science, LILACS, databases of ongoing trials, reference lists of relevant reviews, and we contacted experts and manufacturers. Date of last search was February 2006.

SELECTION CRITERIA

Randomised controlled trials of at least one-year duration in patients with IGT or IFBG, or both, comparing AGI monotherapy with any other intervention.

DATA COLLECTION AND ANALYSIS

Two reviewers read all abstracts, assessed quality and extracted data independently. Discrepancies were resolved by consensus or by the judgement of a third reviewer.

MAIN RESULTS

We included five trials (2360 participants), all investigating acarbose, that included patients with IGT or patients 'at increased risk for diabetes' (n = 1). Study duration was one, three (n = 2), five and six years. One study was at low risk of bias and four studies at high risk of bias. Except for the outcome incidence of type 2 diabetes in acarbose versus no treatment (two studies), meta-analyses were not possible. Data from the study at low risk of bias suggests that acarbose decreases the occurrence of type 2 diabetes (NNT = 10), cardiovascular events (NNT = 50, based on 47 events, study not initially powered for this outcome), post-load blood glucose (-0.6 mmol/L, 95% CI -1.0 to -0.3) and body mass index (0.3 kg/m(2), 95% CI -0.1 to -0.5). No statistically significant effects were observed on mortality, other morbidity, glycated haemoglobin, fasting blood glucose, lipids and blood pressure. The effects on the incidence of type 2 diabetes were confirmed in two studies at high risk of bias (OR 0.2, 95% CI 0.1 to 0.6). Adverse effects were mostly of gastro-intestinal origin (OR 3.5, 95% CI 2.7 to 4.4).

AUTHORS' CONCLUSIONS

There is evidence that acarbose reduces the incidence of type 2 diabetes in patients with IGT. However, it is unclear whether this should be seen as prevention, delay or masking of diabetes. Acarbose may prevent the occurrence of cardiovascular events, but this finding needs to be confirmed in more studies.

A review of the economic evidence for acarbose in the prevention of diabetes and cardiovascular events in individuals with impaired glucose tolerance

The highly prevalent, prediabetic condition of impaired glucose tolerance (IGT) confers a high risk for type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD). There is an emerging body of cost-effectiveness literature in the management of IGT. For acarbose, an alpha-glucosidase inhibitor, economic analyses have been conducted for Spain, Germany, Sweden and Canada. In Spain, acarbose was more effective and less costly (dominant) compared with placebo. In Germany, the cost per patient free of diabetes was under Pounds 800; acarbose was dominant for those at high risk for T2DM, CVD or both, and a similar outcome in the Swedish study. In Canada, acarbose was dominant compared with no intervention and very cost-effective compared with metformin [C Dollars 1798/life years gained (LYG)]. The particularly cost-effective outcomes or cost savings delivered by acarbose for IGT subjects at high risk for T2DM and/or CVD render an IGT-intervention program prioritised to such high-risk individuals an economically attractive strategy.