單一醫學中心門診抗生素的使用分析

Outpatient Prescription of Oral Antibiotics in a Medical Center

抗生素的過度使用與不適當使用，是造成抗生素抗藥性發生的主因。除了住院病人以外，門診病人亦會接受抗生素治療。為了進一步了解本院門診抗生素的使用現況，故而進行此次的門診用藥分析。藉由回溯性評估，96 年1 月至96 年6 月的門診病患，年齡≧18 歲且使用口服抗生素（ATC，J01）；依年齡層上分為兩組，一組為18~64 歲，一組為≧65 歲。抗生素的計算方式：以WHO 所公告之DDD（defined daily dose）為基準，計算單位為DID（DDD／1,000 人次日）。同時，比較廣效性與窄效性類抗生素使用的變化，並且以Chi-square for trend 來檢測廣效性抗生素的用藥趨勢與年齡層上的變化；及linear regression 來探討其用量趨勢。本研究期間，門診就醫患者共808,930 位，平均開方率約3.71%；抗生素耗用量約5.4DID均較歐美國家研究（抗生素耗用量約12.6DID）為低。抗生素的使用類別中以penicillins 類居多，其次為cephalosporins 與fluoroquinolones 類。就年齡層上比較，老年人選用廣效性抗生素的處方頻率較一般成人高（P=0.001）。於各科作比較，抗生素的開方率及抗生素耗用量，以口腔外科的開方率（70.3%）及抗生素耗用量（42.9 DID）最高。但就廣效性抗生素使用而言，以胃腸科與胸腔科的處方率，比率較高；耗用量方面，則以感染科、胸腔科與整形外科的耗用量較高。與歐美國家研究相較，本院門診抗生素的平均處方率及耗用量均較低。針對高使用量與廣效性抗生素耗用量高的科別，需進一步評估用藥情形，以改善門診抗生素的使用合理性。

Overuse and inappropriate use of antibiotics is the major reason causing antibiotic resistance. In addition to inpatients, outpatients may also receive antibiotic treatment as well. We analyzed trends of antibiotics usage in the Outpatient Department to further understand the appropriateness of use of antibiotics. This is a retrospective study. Subjects, aged >18 and using oral antibiotics (ATC, J01), were collected from Outpatient Departments, starting from Jan. through Jun. 2007. Those subjects are divided into two groups: subjects18-64 y and subjects≧ 65y. Antibiotics are calculated based on DDD (defined daily dose) bulletined by WHO, calculating unit is as DID (DDD/ per 1000 inhabitants per day). Meanwhile, changes of use of broad-spectrum and narrow-spectrum antibiotics were also studied in two groups. Chi-square test was used to compare of use of broad-spectrum antibiotics, to see if it changes with the subject’s age. In total, 808,930 patients visited our Outpatient Departments during this 6-month study period. The average rate of prescription is 3.71%; consumption of antibiotics is about 5.4DID, which is lower compare to those studies in western countries. (12.6DID). Penicillins have the largest consumption among antibiotics, followed by cephalosporins and quinolones. Older elderly people（≧65 years）were more choice broad spectrum antibiotics than adults.（p<0.001）In terms of rates of prescriptions and consumption of antibiotics among various departments, department of dental surgery has the highest rate of prescriptions (70.3%) and highest consumption of antibiotics (42.9DID). In terms of use of broad-spectrum antibiotics, departments of chest medicine and gastro-enterology have the highest rates of prescriptions. In terms of consumption, departments of infectious diseases, chest medicine, and plastic surgery are higher. In comparison with those in Western countries, rates of prescriptions and consumption of antibiotics are lower at our Outpatient Departments. Further evaluation of medication at departments which have higher consumption of antibiotics is needed to improve appropriateness of use of antibiotics at Outpatient Departments.