Assessing Effectiveness of Antibiotic Therapy Against Gram-Negative Bacteria in a Saudi Hospital Using a Drug Resistance Index

Background: Assessing the effectiveness of antibiotics and communicating the problem of resistance is essential when devising antimicrobial stewardship programs in hospital settings. The drug resistance index (DRI) is a useful tool that combines antibiotic consumption and bacterial resistance into a single measure. In this study, we used the DRI to assess the impact of introducing a new antibiotic restriction form on antibiotic effectiveness for the treatment of gram-negative infections in the intensive care unit (ICU). Methods: We conducted a before-and-after intervention study from 2015 to 2017 at King Abdulaziz Medical City, a tertiary-care facility in Jeddah, Saudi Arabia. The antibiotic susceptibility of gram-negative bacteria and antibiotic prescribing rates for antibiotics indicated for gram-negative bacteria were assessed to evaluate the impact of a new antibiotic restriction form introduced in the ICU in July 2016. Changes in antibiotic effectiveness before and after the intervention were evaluated by calculating the DRI for 4 of the most common gram-negative pathogens and 8 commonly used antibiotic classes. Results: The overall DRI for the adult ICU (59.45) was higher than the hospital-wide DRI (47.96). A higher DRI was evident for carbapenems and antipseudomonal penicillins + β-lactamase inhibitors. A. baumannii had the highest DRI, followed by K. pneumoniae in both the adult ICU and hospital-wide. After implementation of antibiotic restriction in the adult ICU, the DRI for carbapenems was significantly lower in the postintervention phase, from 31.61 to 26.05 (P = 0.031). Conclusions: DRI is a useful tool for tracking the effectiveness of antibiotics over time. The results highlight the importance of having effective antibiotic stewardship program in healthcare settings as well as regular feedback of antibiotic consumption data to the stakeholders to keep the antibiotic prescriptions in check, thereby ensuring their sustained effectiveness.Funding: NoneDisclosures: None