RESUMO
New injectable antimicrobial agents are generally costly and broad-spectrum. Overusage results in unnecessary economic loss and multi-drug resistant organisms. Effective strategies for decreasing costs without compromising patient care are required. This study aimed to evaluate the economic impact of a system using an antimicrobial order form to assist rational usage of expensive antimicrobial agents. The study was performed during 1988-1996 at a 900-bed, tertiary-care, medical school hospital in Bangkok. The target drugs were 3 costly, broad-spectrum antibacterial drugs, namely imipenem, vancomycin, and injectable ciprofloxacin. The restriction of these 3 drugs was started in 1992 and was extended to netilmicin and ceftazidime in 1995. A filled antimicrobial order form (AOF) was required by pharmacists before dispensing the drugs. The AOF guided the physicians to give explicit information about anatomic diagnosis, etiologic diagnosis, and suspected antimicrobial resistance patterns of the organisms. It also contained information about indications of the restricted drugs. The filled forms were audited daily during working days by the chairman of The Hospital Antibiotic Committee. Feedback was given to the prescribers by infectious disease specialists at least twice a week. The strategy was endorsed by the executive committee of the hospital. Impact of AOF without endorsement, audit and feedback, was evaluated in 1996. The expenditures of the drugs were adjusted to the average admitted patient-days per fiscal year of the study period. The system with endorsement was well accepted and could be maintained for 4 years. The adjusted expenditures per year of the 3 restricted antibiotics were 1.41-1.87 million baht less (22-29%) in 1992-1994 than the pre-intervention year 1991. The cost reduction of imipenem and injectable ciprofloxacin could also be maintained for 1995 but not vancomycin for which use increased. The costs of these 3 restricted drugs increased very sharply (69%) in 1996 when there was loss of endorsement and capacity to perform auditing and feed back by infectious disease specialists. The system did not work with ceftazidime which was commonly used for febrile neutropenia and nosocomial infections.