Distribution of prescription drug exposures in the elderly: Description and implications

Using data from a comprehensive prescription drug benefit program in British Columbia, we studied the distribution of prescription drug expenditures and exposures in the community-dwelling elderly over a 1-year period. Overall, 84% of the population was exposed to at least one prescription drug. The 11% of individuals with the highest level of use accounted for 50% of total drug expenditures. Individuals 65 to 74 years of age were exposed to a median of 2.2 different drugs during the year compared to a median of 3.8 for those 75 years of age and over. Twenty-four percent of the 65- to 74-year-old population were exposed to six or more different drugs during a 1-year period compared to 37% of the 75 years and over population. Central nervous system and cardiovascular drugs were most commonly responsible for multiple drug exposures. Forty eight percent of the individuals exposed to six or more different drugs received prescriptions from three or more different physicians. In British Columbia, 98% of the elderly receiving six or more different drugs received at least one prescription from a general practitioner or a family practitioner.