R analysis shows how UK health system could save £200m

According to an analysis by Prescribing Analytics (a joint venture of technologists and doctors in the UK), Britain's cash-strapped National Health Service (NHS) is overspending on prescription drugs. While cheaper (but equally effective) generic drugs are widely available for many treatments, some doctors continue to prescribe patented drugs which can cost 10 times as much — and often much more. The problem varies regionally: for example, in the administrative region including the city of York nearly 30% of prescriptions for statins (drugs used to lower cholesterol levels) are for expensive non-generics:

Looked at another way, a nearly 70% generic prescribing rate seems pretty good. But the cost differential in generics vs patented drugs is the key here: generic Simvastatin (in blue below) still represents a small fraction of the costs for prescribed statins, compared to non-generic drugs containing Atorvastatin and Rosuvastatin.  According to the study:

Guidelines for that period said that the generic Simvastatin should be a default option for patients. Wherever the percentage of branded items is high, it represents potential to make big savings by switching. For example, if two thirds of the proprietary drugs had switched to the generic forms of the same drugs in the year to June 2012, this would have saved £200 million pounds. Any savings could be used to help other patients.

The analysis was done using R statistics software (and the R code is available for download at github). The prescription data is available thanks to the open data practices of the NHS, but unfortunately a precise estimate of cost savings isn't currently possible because prescription drug price data isn't public.

Prescription Analytics: NHS efficiency savings: the role of prescribing analytics (via Ben Goldacre)

Update: Corrected the description of statins in the first paragraph.