Generic eRx Approaches GDR

Post date: Nov 18, 2010 9:11:42 AM

Stenner et al (2010) report that generic substitution decision support on e-prescribing reached 58.1% by 3Q 2008 when data collection ended. This should be no surprise given that the formulary check being done by the e-prescriber mimics the one by the pharmacy.

The generic dispensing ratio (GDR) for 3Q 2008 was 59.9% based on pharmacy claims (Liberman & Roebuck, 2010). Since most states allow generic substitution by the pharmacist, all the Stenner et al study shows is that e-prescribers can do nearly as good a job as a pharmacist substituting for generics. But I don't see any support for the claim that e-prescribing saves the "system" money as advocates have claimed. Does it matter to the system where the prescription gets changed to generic?

Generic substitution has been going on for years albeit by the pharmacist rather than the prescriber. Note that GDR went from 53.3% to 60.6% from start of 2007 to end of 2008 reflecting increased availability of generic formulations and probably some economic pressures (to switch to generics) on patients due to the recession. Expect further increases in GDR especially as blockbusters like Lipitor become available as generics in 2011.

References:

Liberman, JN & Roebuck, MC 2010, 'Prescription Drug Costs and the Generic Dispensing Ratio', J Manag Care Pharm, Vol. 16, no. 7, pp. 502-6.

Stenner, SP, Chen, Q & Johnson, KB 2010, 'Impact of Generic Substitution Decision Support on Electronic Prescribing Behavior', Journal of the American Medical Informatics Association, Vol. 17, no. 6, pp. 681-8.