The NHS has stumped up an extra £625 million over the past decade on synthetic forms of insulin, when the recommended human alternatives which are considerably cheaper would have probably been just as effective, reveals research published online in BMJ Open.
The finding comes as a UN health summit in New York this week debates how to step up international efforts to tackle the rising global burden of non-communicable diseases, including diabetes.
The authors base their findings on an analysis of publicly available data from the four UK prescription pricing agencies for the years 2000 to 2009. Costs were adjusted for inflation and reported at 2010 prices.
Over the 10 years, the NHS spent a total of £2732 million on insulin, the annual cost rising from £156 million to £359 millionan increase of 130%.
The annual cost of synthetic (analogue) insulin rose from £18.2 million, or 12% of the total, to £305 million, or 85% of the total. The cost of human insulin fell from £131 million, or 84% of total, to £51 million, or 14% of the total.
On the assumption that all patients prescribed insulin analogues could have been prescribed human insulin instead, the NHS could have saved itself £625 million, say the authors.
But even if only half of those patients could have been switched, that's still more than £300 million of savings for the NHS, they say.
The number of people diagnosed with diabetes in the UK has risen to 2.8 million, around 90% of whom have type 2 diabetes. Whereas those with type 1 disease require insulin from the get go, those with type 2 disease tend to be started on insulin later on.
Insulin analogues were developed to better mimic the actions of the insulin manufactured by the body, but it is not clear if the benefits are sufficient to justify their additional cost, say the authors.
"We know that the rise of insulin analogues has had a substantial financial impact on the NHS, yet over the same period there has been no observable clinical benefit to justify that investment," they conclude.
"It is likely that there was and is considerable scope for financial savings," they say, adding: "Most worryingly, the clinical role and safety of insulin for use in people with type 2 diabetes is being questioned."