Screening for type 2 diabetes—where are we now?

Abstract

The American Diabetes Association states that screening for type 2 diabetes should be considered in asymptomatic adults of any age who are overweight or obese, and who have one or more additional risk factors for diabetes.1 In individuals without these risk factors, testing should begin at age 45 years. If tests are normal, they should be repeated at least every 3 years. The effectiveness of early identification of diabetes through mass screening of asymptomatic individuals compared with no screening has yet to be clearly shown. Nevertheless, diabetes meets established criteria for conditions in which early detection is appropriate.1 Screening should be sequential, not a one-time event.2 The cost-effectiveness analysis presented by Richard Kahn and colleagues in The Lancet today, is distinct from other such analyses in that it addresses sequential screening.3 These researchers compared the cost-effectiveness of eight different strategies for testing asymptomatic individuals with the strategy of testing people only after symptoms of diabetes or cardiovascular disease have developed. An assumption was made that people diagnosed with diabetes will be treated thereafter to the same level that those with diabetes are presently being treated in the USA to prevent cardiovascular and microvascular events. Six of the simulated strategies are population-based and not targeted to high-risk populations. That approach is surprising because targeted screening is widely accepted as the preferred method for detection of diabetes in asymptomatic individuals.[1], [4], [5], [6] and [7] However, today's analysis included the option of repeated opportunistic screening during consultations for the management of hypertension. The study showed that strategies in which screening is done opportunistically in combination with blood pressure measurement and lipid testing have the lowest cost per quality-adjusted life-year. As Kahn and colleagues suggest, the use of a risk assessment method before the formal screening might improve cost-effectiveness. The results of today's analysis were not compared with other cost-effectiveness studies. The differences, however, between the mathematical models and the Archimedes model (as used by Kahn and colleagues) are discussed in this analysis. The Archimedes model includes biological variables and outcomes relevant to diabetes and its complications. Every variable in the model is estimated from one or more empirical sources.8 The outcomes of each individual are calculated and transformed into simulated population outcomes. The population used in Kahn and colleagues' study was representative of the US population, and differences in race or ethnic origin or differences in behaviours between northern American and European or Asian people might make the results less Refers to: Age at initiation and frequency of screening to detect type 2 diabetes: a cost-effectiveness analysis The Lancet, Volume 375, Issue 9723, 17 April 2010-23 April 2010, Pages 1365-1374, Richard Kahn, Peter Alperin, David Eddy, Knut Borch-Johnsen, John Buse, Justin Feigelman, Edward Gregg, Rury R Holman, M Sue Kirkman, Michael Stern, Jaakko Tuomilehto, Nick J Wareham PDF (364 K) |