Abstract
BackgroundAntibiotic 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.MethodsDuring 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.ResultsBroad-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.ConclusionsThere 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.
Highlights
Antibiotic consumption in hospitals is commonly measured using the accumulated amount of drugs delivered from the pharmacy to ward held stocks
Use of broad-spectrum antimicrobial agents broadspectrum antibiotics (BSAs) use during the 26 study weeks ranged from 12.8 Defined daily doses (DDDs)/100 bed days in one urological ward to 24.5 DDDs/ 100 bed days in the pulmonary diseases ward
BSA amounts ranged from 615.3 DDDs at one urological ward to 1144.8 DDDs at the pulmonary diseases ward (Table 1), which represents 19.4% - 26.3% of the total consumption of all systemic anti-bacterial agents (ATC group J01)
Summary
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, the impact of the length of the registration periods, has not been evaluated and such evaluation was aim of the study. The most common way of measuring antibiotic use in hospitals is to apply sales data extracted from hospital pharmacy computer systems. In a recent survey of hospital pharmacy practice in Europe it was found that 70% of hospitals hold antibiotic stocks at the wards [5]. When wards purchase drugs from the pharmacy, there will necessarily be a time lag from ordering until consumption. Differences between sales figures and actual drug use might be expected because of variation of stock size over time, discarding of expired drugs, and exchanges of drugs between wards
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
