Department of Infectious Diseases, Oslo University Hospital Aker, Trondheimsveien 235, NO-0514 Oslo, Norway.
BMC Med Res Methodol. 2011 Dec 13;11:166. doi: 10.1186/1471-2288-11-166.
Antibiotic consumption in hospitals is commonly measured using the accumulated amount of drugs delivered from the pharmacy to ward held stocks. The reliability of this method, particularly the impact of the length of the registration periods, has not been evaluated and such evaluation was aim of the study.
During 26 weeks, we performed a weekly ward stock count of use of broad-spectrum antibiotics--that is second- and third-generation cephalosporins, carbapenems, and quinolones--in five hospital wards and compared the data with corresponding pharmacy sales figures during the same period. Defined daily doses (DDDs) for antibiotics were used as measurement units (WHO ATC/DDD classification). Consumption figures obtained with the two methods for different registration intervals were compared by use of intraclass correlation analysis and Bland-Altman statistics.
Broad-spectrum antibiotics accounted for a quarter to one-fifth of all systemic antibiotics (ATC group J01) used in the hospital and varied between wards, from 12.8 DDDs per 100 bed days in a urological ward to 24.5 DDDs in a pulmonary diseases ward. For the entire study period of 26 weeks, the pharmacy and ward defined daily doses figures for all broad-spectrum antibiotics differed only by 0.2%; however, for single wards deviations varied from -4.3% to 6.9%. The intraclass correlation coefficient, pharmacy versus ward data, increased from 0.78 to 0.94 for parenteral broad-spectrum antibiotics with increasing registration periods (1-4 weeks), whereas the corresponding figures for oral broad-spectrum antibiotics (ciprofloxacin) were from 0.46 to 0.74. For all broad-spectrum antibiotics and for parenteral antibiotics, limits of agreement between the two methods showed, according to Bland-Altman statistics, a deviation of ± 5% or less from average mean DDDs at 3- and 4-weeks registration intervals. Corresponding deviation for oral antibiotics was ± 21% at a 4-weeks interval.
There is a need for caution in interpreting pharmacy sales data aggregated over short registration intervals, especially so for oral formulations. Even a one-month registration period may be too short.
医院抗生素的使用通常通过从药房输送到病房库存的药物累积量来衡量。该方法的可靠性，特别是登记期限的影响，尚未得到评估，而评估就是本研究的目的。
在 26 周的时间里，我们对五个病房中广谱抗生素（第二代和第三代头孢菌素、碳青霉烯类和喹诺酮类）的使用情况进行了每周的病房库存盘点，并将同期的药房销售数据与之进行了比较。抗生素的定义日剂量（DDD）被用作测量单位（世界卫生组织 ATC/DDD 分类）。使用内类相关分析和 Bland-Altman 统计对不同登记间隔的两种方法获得的消耗数据进行了比较。
广谱抗生素占医院使用的所有全身抗生素（ATC 组 J01）的四分之一到五分之一，且在病房之间有所不同，从泌尿科病房的 12.8 DDD/100 个床位日到肺病病房的 24.5 DDD。在 26 周的整个研究期间，所有广谱抗生素的药房和病房定义日剂量数据仅相差 0.2%；然而，对于单个病房，偏差从-4.3%到 6.9%不等。随着登记期（1-4 周）的增加，类内相关系数（药房与病房数据）从静脉内广谱抗生素的 0.78 增加到 0.94，而相应的口服广谱抗生素（环丙沙星）的数值从 0.46 增加到 0.74。对于所有广谱抗生素和静脉内抗生素，根据 Bland-Altman 统计，两种方法之间的一致性界限表明，在 3 周和 4 周的登记间隔下，平均 DDD 的偏差在±5%或以下。口服抗生素的相应偏差在 4 周间隔时为±21%。
在解释短期登记间隔内汇总的药房销售数据时需要谨慎，尤其是对于口服制剂。即使一个月的登记期也可能太短。
