COST-EFFECTIVENESS OF THE PRIMARY PREVENTION OF NON-INSULIN-DEPENDENTDIABETES-MELLITUS

Non-insulin dependent diabetes mellitus (NIDDM) is a chronic disease, with increasing prevalence widely reported NIDDM is associated with hi gh 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, e nhanced fitness and nutrition modification. The research question addr essed in this article is whether the prevention of NIDDM is cost-effec tive compared with other possible uses of our health care resources an d whether some approaches to NIDDM prevention are more cost-effective than others. Program types analysed are surgery, group behavioural pro gram, media campaign, general practitioner (family physician) lifestyl e advice, and intensive diet and behavioural programs. Target groups i nclude seriously obese persons, women with previous gestational diabet es, overweight men and all adults. Expected diabetes years and life ye ars were modelled for hypothetical intervention and control cohorts an d used, with information an program cost, to derive estimates of cost- effectiveness, expressed as cost per diabetes year avoided and cost pe r life year gained. Markov modelling was used to track states of norma l glucose tolerance, impaired glucose tolerance (IGT) and NIDDM for in tervention and control cohorts. Expected life years were calculated th rough application of age and gender specific mortality vectors, adjust ed for diabetic state and weight loss. Expected savings in health care costs from NIDDM prevention were based on estimated annual cost of NI DDM management and were used to derive net cost-effectiveness ratios. The group program for overweight men and media programs were identifie d as extremely worthwhile, generating estimated net savings in health care resources, while reducing diabetes incidence and extending life e xpectancy. The behavioural/diet programs for high risk groups were fou nd 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$72 0) 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 high ly cost-effective. The development and funding of pilot programs for N IDDM prevention is recommended to test these findings and address the increasing incidence of NIDDM.