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| Cost-effectiveness of intensified versus conventional multifactorial intervention in type 2 diabetes: results and projections from the Steno-2 study |
| Gaede P, Valentine W J, Palmer A J, Tucker D M, Lammert M, Parving H H, Pedersen O |
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Record Status This is a critical abstract of an economic evaluation that meets the criteria for inclusion on NHS EED. Each abstract contains a brief summary of the methods, the results and conclusions followed by a detailed critical assessment on the reliability of the study and the conclusions drawn. CRD summary This economic evaluation assessed the cost-effectiveness of an intensive versus conventional therapy for patients with type two diabetes and microalbuminurea. The implementation of an eight-year intensive programme was a cost-effective alternative to the conventional therapy from the perspective of the health care payer in Denmark. The study was based on valid methodology, although some data sources were not extensively reported. The authors’ conclusions appear to be robust. Type of economic evaluation Cost-effectiveness analysis, cost-utility analysis Study objective This economic evaluation assessed the cost-effectiveness of an intensive versus conventional intervention for patients with type two diabetes and microalbuminurea. Interventions An intensive programme for patients with type two diabetes and microalbuminurea was compared with the conventional multifactorial therapy. Either programme was delivered for an eight-year period. The intensive programme consisted of strict attention to glycaemic control and aggressive management of cardiovascular risk factors. Location/setting Denmark/primary and secondary care. Methods Analytical approach:This economic evaluation was based on a Markov model, which incorporated recent data from the Steno-2 study. A lifetime horizon was considered. The authors stated that the analysis was carried out from the perspective of the national health care payer.
Effectiveness data:Recent clinical data on the efficacy of the two therapies came from the published Steno-2 study, which was a randomised, open-label, parallel trial, undertaken by the Steno Diabetes Center in Denmark. The study enrolled 80 patients in each group and they were followed-up for 7.8 years. Long-term projections of the Steno-2 results were based on selected published studies, such as the UK Prospective Diabetes Study (UKPDS), which was used to estimate the age-specific risk of cardiovascular events. The primary end-point of the clinical trial was the composite risk of cardiovascular disease.
Monetary benefit and utility valuations:The utility valuations were derived from published studies, the details of which were not given.
Measure of benefit:Quality-adjusted life-years (QALYs) and life-years gained (LYs) were used as summary benefit measures and a 3% annual discount rate was applied.
Cost data:The costs were derived from Danish databases and included those of the health services for drugs, physician consultations, and interventions associated with diabetes-related complications, which were dialysis, revascularisation procedures, and amputation. A breakdown of the cost items was reported. The resource consumption was mainly based on data from the Steno-2 study. All costs were in Euros (EUR), for the price year of 2005. They were discounted at an annual rate of 3%.
Analysis of uncertainty:A non-parametric bootstrapping approach was adopted using a first-order Monte Carlo simulation, which generated cost-effectiveness acceptability curves. Alternative scenarios considered a different time horizon (eight years), different discount rates (from 0 to 6%), an alternative setting (both therapies delivered in a primary care setting), and different assumptions on the magnitude of the benefits (lower benefits for patients in the intensive therapy arm). Results The lifetime costs were EUR 45,521 (standard deviation, SD: 19,697) with intensive therapy and EUR 41,319 (SD: 27,500) with conventional therapy. The expected discounted life expectancy was 13.4 (SD: 4.8) with intensive therapy and 12.4 (SD: 4.5) with conventional therapy. The expected QALYs were 10.2 (SD: 3.6) with intensive therapy and 8.6 (SD: 2.7) with conventional therapy. The incremental cost per QALY gained with intensive over conventional therapy was EUR 2,538, while the expected cost per LY gained was EUR 3,927.
The probabilistic sensitivity analysis showed that, at a willingness to pay threshold of EUR 40,000 per QALY, the intensive therapy had a 74% probability of being cost-effective.
The deterministic sensitivity analysis indicated that the cost of physician consultation and the time horizon were the most influential model inputs. For example, assuming that both the intensive intervention and the conventional therapy were delivered in a primary care setting (in the base case the intensive therapy was delivered at the Steno Diabetes Center), the conventional therapy was dominated. Assuming a shorter time-horizon of eight years, the incremental cost per QALY for the intensive versus conventional intervention rose to EUR 41,934. In all the other cases, the base-case results did not change substantially. Authors' conclusions The authors concluded that the implementation of an eight-year intensive programme for patients with type two diabetes and microalbuminurea was a cost-effective alternative to the conventional therapy from the perspective of the health care payer in Denmark. CRD commentary Interventions:The selection of the two strategies appears to have been appropriate. However, a description of the services provided within each programme was not given.
Effectiveness/benefits:The bulk of the clinical evidence came from a randomised controlled trial (RCT), which is generally considered to be a valid source of evidence given its robust design. Thus, even though the methods and results of this RCT were published in a separate report, the clinical data should have had a degree of internal validity. Supplementary data were derived from the literature, using well-known sources. The use of QALYs as the summary benefit measure appears to have been appropriate given the impact of the disease on both life expectancy and quality of life. No information on the instruments used to derive the utility valuations from the published sources was provided.
Costs:The analysis of costs reflected the perspective, but a breakdown of the cost items was not reported. The resource consumption patterns were based on the main clinical study that supplied the effectiveness data. The price year, the use of discounting, and the use of alternative estimates for some economic assumptions were reported. In general, the cost analysis was carried out transparently and satisfactorily.
Analysis and results:The use of an incremental approach to combine the costs and benefits was appropriate. The issue of uncertainty was satisfactorily addressed using two different approaches which considered both the global and individual variations in the model inputs. The findings were clearly reported. The authors noted that their findings were likely to be an underestimate of the benefits of the intensive approach due to the use of conservative assumptions. The issue of generalisability was not explicitly addressed, but the authors noted that their findings should be transferred only to similar patient populations.
Concluding remarks:The study was based on valid methodology, although some data sources were not extensively reported. The authors’ conclusions appear to be robust. Funding Supported by grants from the Steno Diabetes Center, and Novo Nordisk A/S. Bibliographic details Gaede P, Valentine W J, Palmer A J, Tucker D M, Lammert M, Parving H H, Pedersen O. Cost-effectiveness of intensified versus conventional multifactorial intervention in type 2 diabetes: results and projections from the Steno-2 study. Diabetes Care 2008; 31(8): 1510-1515 Other publications of related interest Gaede P, Vedel P, Larsen N, et al. Multifactorial intervention and cardiovascular disease in patients with type 2 diabetes. N Engl J Med 2003;348:383-93.
Clarke P, Gray A, Adler A, et al. Cost-effectiveness analysis of intensive blood-glucose control with metformin in overweight patients with type II diabetes (UKPDS No. 51). Diabetologia 2001;44:298-304.
Jonsson B, Cook JR, Pedersen TR. The cost-effectiveness of lipid lowering in patients with diabetes: results from the 4S trial. Diabetologia 1999;42:1293-1301. Indexing Status Subject indexing assigned by NLM MeSH Cost-Benefit Analysis; Denmark; Diabetes Mellitus, Type 2 /drug therapy /economics; Hospitalization /economics /statistics & Humans; Life Expectancy; Markov Chains; Quality of Life; Randomized Controlled Trials as Topic; Risk Assessment; Treatment Outcome; numerical data AccessionNumber 22008102251 Date bibliographic record published 31/03/2009 Date abstract record published 01/07/2009 |
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