The cost of diabetes and its complications: a review

Diabetes mellitus is a disease with major long-term implications, not only for the health and well-being of affected individuals, but also for costs to the National Health Service. Treatment of the disease and its complications takes up to 4-5% of total health care expenditure in the UK. These costs are dominated by in-patient care for the complications arising from diabetes. This paper presents a review of studies which have been carried out on the costs of diabetes and its complications. For such a chronic and potentially disabling disease with numerous complications it is surprising that costs have not been more extensively researched. A large amount of data are available about the implications of diabetes in terms of incidence and prevalence, but few costs have been collected, particularly indirect and marginal costs. Moreover, researchers have frequently failed to distinguish between insulin dependent (IDDM) and non-insulin dependent (NIDDM) diabetes, which have different aetiologies and, therefore, different costs, and few studies have included diabetes as a secondary diagnosis. The studies which are available have tended to focus on direct costs, for example, the costs of hospital care, consultations and drugs, because they are the easiest to measure. Fewer studies have included indirect costs, such as the effect of time lost from work, early retirement and premature death, because of the difficulties in assigning monetary values to these factors. The most important contributors to the costs of diabetes are those of treating complications such as eye and limb disease, heart disease, neuropathy and nephropathy. Individual studies have assessed methods of treating complications such as end stage renal disease and lower limb problems. The effect of the disease on patient quality of life has not been assessed, nor have there been cost-effectiveness studies of diabetes. New advances in treatment, such as new monitoring methods for home glucose measurements, and laser treatment for neuropathy all have the potential to improve patient quality of life, but have yet to be evaluated. Primary interventions, for example dietary advice, and education, are inexpensive but are frequently less successful than secondary intervention which is aimed at preventing the development of diabetic complications.