Can rational prescribing be assessed?

The prescribing of a group of young general practitioners was assessed, before and after educational intervention, using five parameters of rational prescribing. The proportion of drugs prescribed by their generic name, and the proportion falling within a basic formulary for general practice increased significantly even though the participating doctors had neither been involved in the compilation of the formulary nor been given a copy of it. Items prescribed bygeneric name rose from 45 to 74% and the proportions of new and repeat items within the formulary rose by 73 to 83% and 68 to 77% respectively. It appears that discussions about rational prescribing lead to similar changes in prescribing as involvement in the compilation of a formulary.The notion of an ;essential drugs list' for general practice is described, and three easily applied measures of rational prescribing are suggested: (1) the proportion of patients not given a prescription, (2) the proportion of drugs written in their generic form and (3) the proportion of drugs falling within a general practice ;essential drugs list'.