|The objective of this study was to determine the cost-benefit ratio for the prevention of adverse drug reaction (ADR) in in-patient department, Khunhan hospital, Sisaket province during September 1st to December 31st, 2007. This study was a prospective study, divided into 3 parts i.e., determination of the incidence of ADR, determination of the cost-benefit ratio of ADR prevention by pharmacist, and analysis of the test of agreement between criteria used to classify preventable ADR (pADR). There were 2,397 patients who were hospitalized at Khunhan hospital during the period of the study. The incidence of ADR was 4.71%, in which 0.58% of patients were admitted due to ADR problems. According to ADR prevention by pharmacist, 92 cases of potential pADR were reported, in which all of those were pADR. Pharmacists then provided 92 cases of intervention to health care professionals, in which 75 were entirely accepted (81.52%), and 17 were not accepted (18.48%). As a result of pharmacist interventions, 78 cases of pADR were actually occurred and 11 cases of pADR (11.96%) were prevented. In addition, pharmacist interventions reduced the severity of ADR by which the “severe” ADR were reduced from 17 to 0, the “moderately severe” ADR were reduced from 53 to 14 and most of the ADR were reported as “mild” ADR. Costs of ADR prevention by pharmacist during 4 months were accounted for 6,050.06 Bath or 12,151.80 Bath per year. Benefits of the act were calculated approximately of 70,591.96 Bath. Cost-benefit ratio was settled at 11.67, meaning that the benefits were more superior to the costs of ADR prevention. Test of agreement between the Schumock and Thornton Criteria (1992) and the French Standardize Preventability Scale were resulted in moderately agreement with kappa statistic of 0.559 (p<0.05).
From this study, the prevention of ADR by pharmacist had benefits in both quality and economic aspects. However, good systemic management might be able to prevent the incidence of some preventable ADR e.g. advisory system of gastro-intestinal-irritated drug, development of counseling system for insulin-injected patient. Moreover, all health care professionals should be well educated and practiced for ADR monitoring, in order to gain more experience and be able to resolve the problems for the patients.