Diffusion of innovation II: Formulary acceptance rates of new drugs in teaching and non-teaching British Columbia hospitals--a drug development perspective.

Diffusion theory was used to examine differences in adoption rates of new drugs by British Columbia teaching and non-teaching hospitals. Surveys were mailed in September 1990 to 41 hospital pharmacies (response rate = 88%), requesting hospital pharmacy directors to provide formulary inclusion dates of 29 study drugs marketed between July 1987 and March 1990. Of the 36 initial responses, 31 were suitable for further analysis and these were surveyed again in April 1993 (response rate = 100%) as to the formulary status of drugs not initially approved. The second survey ensured that all study drugs would have at least 36 months on the Canadian market when determining formulary acceptance times. Of the 29 study drugs, six were not approved for use in any of the 31 study hospitals. The six teaching hospitals had a median formulary approval time of 8.0 months compared to 12.8 months in the 25 non-teaching hospitals for the 23 study drugs. Although 21 of 23 study drugs were approved for use earlier in teaching hospitals than non-teaching hospitals, only alfentanil was found to be adopted significantly earlier (U = 11, n1 = 5, n2 = 19, alpha = 0.05). Variations in formulary approval times for new drugs have a bearing on patient care, Pharmacy and Therapeutics Committees, hospital budgets, and pharmaceutical firm revenues.