Cost-effectiveness of the primary prevention of non-insulin dependent diabetes mellitus

Non-insulin dependent diabetes mellitus (NIDDM) is a chronic disease, with increasing prevalence widely reported. NIDDM is associated with high rates of morbidity and premature mortality and is the cause of high health service use. There is clinical, epidemiological and scientific evidence that NIDDM is potentially preventable through weight loss, enhanced fitness and nutrition modification. The research question addressed in this article is whether the prevention of NIDDM is cost-effective compared with other possible uses of our health care resources and whether some approaches to NIDDM prevention are more cost-effective than others. Program types analysed are surgery, group behavioural program, media campaign, general practitioner (family physician) lifestyle advice, and intensive diet and behavioural programs. Target groups include seriously obese persons, women with previous gestational diabetes, overweight men and all adults. Expected diabetes years and life years were modelled for hypothetical intervention and control cohorts and used, with information on program cost, to derive estimates of cost-effectiveness, expressed as cost per diabetes year avoided and cost per life year gained. Markov modelling was used to track states of normal glucose tolerance, impaired glucose tolerance (IGT) and NIDDM for intervention and control cohorts. Expected life years were calculated through application of age and gender specific mortality vectors, adjusted for diabetic state and weight loss. Expected savings in health care costs from NIDDM prevention were based on estimated annual cost of NIDDM management and were used to derive net cost-effectiveness ratios. The group program for overweight men and media programs were identified as extremely worthwhile, generating estimated net savings in health care resources, while reducing diabetes incidence and extending life expectancy. The behavioural/diet programs for high risk groups were found to be highly cost-effective relative to other health care programs, at an estimated net cost per life year saved of between A$1000 (US$720) and A$2600 (US$1900). Surgery performed poorest, but still well at A$4600 (US$3300) net cost per life year saved, if targeted at persons with IGT. We conclude that the primary prevention of NIDDM can be highly cost-effective. The development and funding of pilot programs for NIDDM prevention is recommended to test these findings and address the increasing incidence of NIDDM.