RESUMEN
Use of antimicrobial agents is highly effective in reduction of morbidity and mortality due to infectious disease. There is, however, evidence that the use of such agents is frequently inappropriate worldwide. Several methods were tried to rationalize the use, and, among these, the preprinted order form (P.O.F.) offered the simplest and most efficient way. We studied the use of the P.O.F. in Siriraj Hospital, Bangkok Thailand, where there was overuse of antimicrobial agents using a historical-controlled intervention study. In period I (no P.O.F.), the antimicrobial overuse was 35 per cent, and this was not reduced by using the P.O.F. in period II (32%), which was one year apart. There was no difference in overuse after adjustment for differences in base-line characteristics which were thought to affect antimicrobial prescriptions i.e. physicians' workload, physicians' knowledge and the method of diagnosis of infectious disease. Reasons for failure of the P.O.F. in unclear. Misdiagnosis was unlikely since the correct diagnosis as revised by attending physicians and specialists was as high as 83 per cent. The fear of malpractice suits was also not the reason because defensive medicine is not a problem in Thailand. The nature of the diseases, which lower the threshold to treat, the clinical immaturity and other unknown factors were thought to play a part in deviation from responsibility to perform according to written-justification.