LAUSR

Background Antimicrobial resistance is correlated with the inappropriate use of antibiotics. Computerised decision support systems may help practitioners to make evidence-based decisions when prescribing antibiotics. Objective This study aimed to evaluate the impact of computerized decision support systems on the volume of antibiotics used. Setting A very large 1200-bed teaching hospital in Birmingham, England. Main outcome measure The primary outcome measure was the defined daily doses/1000 occupied bed-days. Method A retrospective longitudinal study was conducted to examine the impact of computerised decision support systems on the volume of antibiotic use. The study compared two periods: one with computerised decision support systems, which lasted for 2 years versus one without which lasted for 2 years after the withdrawal of computerised decision support systems. Antibiotic use data from June 2012 to June 2016 were analysed (comprising 2 years with computerised decision support systems immediately followed by 2 years where computerised decision support systems had been withdrawn). Regression analysis was applied to assess the change in antibiotic consumption through the period of the study. Result From June 2012 to June 2016, total antibiotic usage increased by 13.1% from 1436 to 1625 defined daily doses/1000 bed-days: this trend of increased antibiotic prescribing was more pronounced following the withdrawal of structured prescribing (computerised decision support systems). There was a difference of means of − 110.14 defined daily doses/1000 bed days of the total usage of antibiotics in the period with and without structured prescribing, and this was statistically significant ( p  = 0.026). From June 2012 to June 2016, the dominant antibiotic class used was penicillins. The trends for the total consumption of all antibiotics demonstrated an increase of use for all antibiotic classes except for tetracyclines, quinolones, and anti-mycobacterial drugs, whereas aminoglycoside usage remained stable. Conclusion The implementation of computerised decision support systems appears to influence the use of antibiotics by reducing their consumption. Further research is required to determine the specific features of computerised decision support systems, which influence increased higher adoption and uptake of this technology.