Trends in hospital antibiotic prescribing after introduction of an antibiotic policy.

Trends in antibiotic prescribing in Grampian were monitored prospectively for seven years from 1986 using computerised ward stock lists and laboratory data relating to all in-patient and out-patient treatments in all Grampian hospitals serving a population of 500,000. The main outcome measures were the number of antibiotics available for routine and restricted uses, annual expenditure and defined daily doses (DDDs) of high expenditure antimicrobial agents. An antibiotic committee introduced a policy and formulary in the third year of the study which had only limited success in controlling prescribing. During the period of the study 30 new antibiotics were considered for inclusion in the hospital formulary, but only seven were incorporated, and all for restricted use only. Despite this, expenditure on antibiotics has more than doubled since 1986, two thirds of the increase being due to the use of new drugs. There was also an increased use of older antibiotics (DDDs increased by 33%), often for no clear reasons, and an overall increase of 46% in DDDs. Antibiotics have increased from 11.9-18.7% as a proportion of the drug budget. These findings highlight the current difficulty in controlling prescribing budgets, the increasing use of antibiotics and the consequent spread of resistance.