Trends in hospital antimicrobial prescribing after 9 years of stewardship.

Trends in antibiotic prescribing in Grampian have been monitored prospectively for 11 years from 1986 using computerized ward stock lists and laboratory data relating to all in-patient and out-patient treatments in all Grampian hospitals. The main outcome measures were the number of antibiotics available for routine and restricted use, 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 has had only limited success in controlling prescribing. This report updates the audit from 1992/3 to 1996/7. During this period 22 new antibiotics were considered for inclusion in the hospital formulary. Seventeen, including seven antiretroviral agents, were incorporated, all for restricted use only. Despite this, expenditure on antibiotics has more than trebled since 1986/7 and increased 50% since 1992/3, two-thirds of the latter increase being due to the use of new drugs, namely anti-HIV drugs, lipid amphotericin derivatives and teicoplanin. Big increases in the use of co-amoxiclav, acyclovir, ciprofloxacin and cefotaxime account for the remainder of the increased expenditure. There was an overall increase of 16.9% in DDDs between 1992/3 and 96/7 to 424.0 DDDs/1000 patient days (393.4 DDDs for antibacterials). These findings highlight the current difficulty in controlling prescribing budgets, the increasing use of antibiotics and the consequent increase of antimicrobial-resistant microorganisms.