A modified method for measuring antibiotic use in healthcare settings: implications for antibiotic stewardship and benchmarking

Antimicrobial consumption in an acute NHS Trust during the COVID-19 pandemic: intervention time series analysis

Objective

To determine the impact of the COVID-19 pandemic on antimicrobial consumption and trends of therapeutic drugs for COVID-19 treatments, including corticosteroids, remdesivir and monoclonal antibodies (tocilizumab) from April 2017 to September 2022 in a secondary care NHS Trust in England.

Methods

A retrospective intervention time series analysis was conducted for April 2017 to September 2022 at the Mid Yorkshire Teaching NHS Trust. Data were retrieved from the pharmacy dispensing system as defined daily doses (DDDs) monthly and reported per 1000 occupied bed days (OBDs). Antimicrobial consumption and COVID-19 treatment options were measured. DDDs were calculated according to the classification of antimicrobials for systemic use (J01) and for other drugs classification. Trends for antimicrobial consumption and other therapeutic drugs for treating COVID-19 were also determined in each wave in England.

Results

During the pandemic: total antibiotic consumption decreased from 826.4 to 728.2 DDDs per 1000 OBDs (P = 0.0067); piperacillin/tazobactam use increased (P < 0.0001) and ciprofloxacin use decreased (P < 0.0001); there were no changes in Access, Watch, Reserve antibiotic use, and the proportion of antifungal consumption was consistent throughout the study. The use of total antibiotics (P = 0.024), levofloxacin (P = 0.0007), piperacillin/tazobactam (P = 0.0015) and co-amoxiclav (P = 0.0198) increased during wave one. Consumption of COVID-19 treatment drugs was highest during wave two, with 624.3 DDDs per 1000 OBDs for dexamethasone (P = 0.4441), 6.8 DDDs per 1000 OBDs for remdesivir (P < 0.0001) and 35.01 DDDs per 1000 OBDs for tocilizumab (P = 0.2544).

Discussion

This study determined the consumption of antimicrobials trends before and during the pandemic. The individual wave antimicrobial consumption indicates maximum consumption in the first wave, advocating for antimicrobial stewardship and preparedness for future pandemics.

Identification of antibiotic consumption targets for the management of Clostridioides difficile infection in hospitals- a threshold logistic modelling approach

BACKGROUND

This study aims to demonstrate the utility of a threshold logistic approach to identifying thresholds for specific antibiotic use associated with Clostridioides difficile infection (CDI) in an English teaching hospital.

METHODS

A combined approach of nonlinear modeling and logistic regression, named threshold logistic, was used to identify thresholds and risk scores in hospital-level antibiotic use associated with hospital-onset, healthcare-associated (HOHA) CDI cases.

RESULTS

Using a threshold logistic regression approach, an incidence greater than 0.2645 cases/1000 occupied bed-days (OBD; 85th percentile) was determined as the cutoff rate to define a critical (high) incidence rate of HOHA CDI. Fluoroquinolones and piperacillin-tazobactam were found to have thresholds at 84.8 and 54 defined daily doses (DDD)/1000 OBD, respectively. Analysis of data allowed calculating risk scores for HOHA CDI incidence rates exceeding the 85th percentile, i.e. entering critical incidence level. The threshold-logistic model also facilitated performing 'what-if scenarios' on future values of fluoroquinolones and piperacillin-tazobactam use to understand how HOHA CDI incidence rates may be affected.

CONCLUSION

Using threshold logistic analysis, critical incidence levels and antibiotic use targets to control HOHA CDI were determined. Threshold logistic models can be used to inform and enhance the effective design and implementation of antimicrobial stewardship programs.

A Threshold Logistic Modelling Approach for Identifying Thresholds between Antibiotic Use and Methicillin-Resistant Staphylococcus aureus Incidence Rates in Hospitals

The aim of this study was to demonstrate the utility of threshold logistic modelling, an innovative approach in identifying thresholds and risk scores in the context of population antibiotic use associated with methicillin-resistant Staphylococcus aureus (MRSA) incidence rates in hospitals. The study also aimed to assess the impact of exceeding those thresholds that resulted in increased MRSA rates. The study was undertaken in a 700-bed hospital in England between January 2015 and December 2021 (84 monthly observations). By employing the threshold logistic modelling approach, we: (i) determined the cut-off percentile value of MRSA incidence that defines a critical level of MRSA; (ii) identified thresholds for fluoroquinolone and co-amoxiclav use that would accelerate MRSA incidence rates and increase the probability of reaching critical incidence levels; (iii) enabled a better understanding of the effect of antibiotic use on the probability of reaching a critical level of resistant pathogen incidence; (iv) developed a near real-time performance monitoring feedback system; (v) provided risk scores and alert signals for antibiotic use, with the ability to inform hospital policies, and control MRSA incidence; and (vi) provided recommendations and an example for the management of pathogen incidence in hospitals. Threshold logistic models can help hospitals determine quantitative targets for antibiotic usage and can also inform effective antimicrobial stewardship to control resistance in hospitals. Studies should work toward implementing and evaluating the proposed approach prospectively, with the aim of determining the best counter-measures to mitigate the risk of increased resistant pathogen incidence in hospitals.

Identifying Antibiotic Use Targets for the Management of Antibiotic Resistance Using an Extended-Spectrum β-Lactamase-Producing Escherichia coli Case: A Threshold Logistic Modeling Approach

The aim of this study was to develop a logistic modeling concept to improve understanding of the relationship between antibiotic use thresholds and the incidence of resistant pathogens. A combined approach of nonlinear modeling and logistic regression, named threshold logistic, was used to identify thresholds and risk scores in hospital-level antibiotic use associated with hospital-level incidence rates of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (E. coli). Threshold logistic models identified thresholds for fluoroquinolones (61.1 DDD/1000 occupied bed days (OBD)) and third-generation cephalosporins (9.2 DDD/1000 OBD) to control hospital ESBL-producing E. coli incidence. The 60th percentile of ESBL-producing E. coli was determined as the cutoff for defining high incidence rates. Threshold logistic analysis showed that for every one-unit increase in fluoroquinolones and third-generation cephalosporins above 61.1 and 9.2 DDD/1000 OBD levels, the average odds of the ESBL-producing E. coli incidence rate being ≥60th percentile of historical levels increased by 4.5% and 12%, respectively. Threshold logistic models estimated the risk scores of exceeding the 60th percentile of a historical ESBL-producing E. coli incidence rate. Threshold logistic models can help hospitals in defining critical levels of antibiotic use and resistant pathogen incidence and provide targets for antibiotic consumption and a near real-time performance monitoring feedback system.

Identifying Targets for Antibiotic Use for the Management of Carbapenem-Resistant Acinetobacter baumannii (CRAb) in Hospitals-A Multi-Centre Nonlinear Time-Series Study

Solutions are needed to inform antimicrobial stewardship (AMS) regarding balancing the access to effective antimicrobials with the need to control antimicrobial resistance. Theoretical and mathematical models suggest a non-linear relationship between antibiotic use and resistance, indicating the existence of thresholds of antibiotic use beyond which resistance would be triggered. It is anticipated that thresholds may vary across populations depending on host, environment, and organism factors. Further research is needed to evaluate thresholds in antibiotic use for a specific pathogen across different settings. The objective of this study is to identify thresholds of population antibiotic use associated with the incidence of carbapenem-resistant Acinetobacter baumannii (CRAb) across six hospital sites in Oman. The study was an ecological, multi-centre evaluation that involved collecting historical antibiotic use and CRAb incidence over the period from January 2015 to December 2019. By using non-linear time-series analysis, we identified different thresholds in the use of third-generation cephalosporins, piperacillin-tazobactam, aminoglycoside, and fluoroquinolones across participating hospitals. The identification of different thresholds emphasises the need for tailored analysis based on modelling data from each hospital. The determined thresholds can be used to set targets for each hospital AMS, providing a balance between access to these antibiotics versus controlling CRAb incidence.

Impact of Multidisciplinary Team Escalating Approach on Antibiotic Stewardship in the United Arab Emirates

Antimicrobial stewardship programs (ASP) are an essential strategy to combat antimicrobial resistance. This study aimed to measure the impact of an ASP multidisciplinary team (MDT) escalating intervention on improvement of clinical, microbiological, and other measured outcomes in hospitalised adult patients from medical, intensive care, and burns units. The escalating intervention reviewed the patients’ cases in the intervention group through the clinical pharmacists in the wards and escalated complex cases to ID clinical pharmacist and ID physicians when needed, while only special cases required direct infectious disease (ID) physicians review. Both non-intervention and intervention groups were each followed up for six months. The study involved a total of 3000 patients, with 1340 (45%) representing the intervention group who received a total of 5669 interventions. In the intervention group, a significant reduction in length of hospital stay (p < 0.01), readmission (p < 0.01), and mortality rates (p < 0.01) was observed. Antibiotic use of the WHO AWaRe Reserve group decreased in the intervention group (relative rate change = 0.88). Intravenous to oral antibiotic ratio in the medical ward decreased from 4.8 to 4.1. The presented ASP MDT intervention, utilizing an escalating approach, successfully improved several clinical and other measured outcomes, demonstrating the significant contribution of clinical pharmacists atimproving antibiotic use and informing antimicrobial stewardship.

Identification of thresholds in relationships between specific antibiotic use and carbapenem-resistant Acinetobacter baumannii (CRAb) incidence rates in hospitalized patients in Jordan

BACKGROUND

Antibiotic resistance is a major threat to public health worldwide. The relationship between the intensity of antibiotic use and resistance might not be linear, suggesting that there might be a threshold of antibiotic use, beyond which resistance would be triggered.

OBJECTIVES

To identify thresholds in antibiotic use, below which specific antibiotic classes have no significant measurable impact on the incidence of carbapenem-resistant Acinetobacter baumannii (CRAb), but above which their use correlates with an increase in the incidence of CRAb.

METHODS

The study took place at a tertiary teaching hospital in Jordan. The study was ecological in nature and was carried out retrospectively over the period January 2014 to December 2019. The outcome time series for this study was CRAb cases. The primary explanatory variables were monthly use of antibiotics and the use of alcohol-based hand rub (ABHR). Non-linear time-series methods were used to identify thresholds in antibiotic use.

RESULTS

Non-linear time-series analysis determined a threshold in third-generation cephalosporin and carbapenem use, where the maximum use of third-generation cephalosporins and carbapenems should not exceed 8 DDD/100 occupied bed days (OBD) and 10 DDD/100 OBD, respectively. ABHR had a significant reducing effect on CRAb cases even at lower usage quantities (0.92 L/100 OBD) and had the most significant effect when ABHR exceeded 3.4 L/100 OBD.

CONCLUSIONS

The identification of thresholds, utilizing non-linear time-series methods, can provide a valuable tool to inform hospital antibiotic policies through identifying quantitative targets that balance access to effective therapies with control of resistance. Further studies are needed to validate the identified thresholds, through being prospectively adopted as a target for antimicrobial stewardship programmes, and then to evaluate the impact on reducing CRAb incidence.

An Assessment of the Impact of Coronavirus Disease (COVID-19) Pandemic on National Antimicrobial Consumption in Jordan

Coronavirus disease 2019 (COVID-19) has overlapping clinical characteristics with bacterial respiratory tract infection, leading to the prescription of potentially unnecessary antibiotics. This study aimed at measuring changes and patterns of national antimicrobial use for one year preceding and one year during the COVID-19 pandemic. Annual national antimicrobial consumption for 2019 and 2020 was obtained from the Jordan Food and Drug Administration (JFDA) following the WHO surveillance methods. The WHO Access, Watch, and Reserve (AWaRe) classification was used. Total antibiotic consumption in 2020 (26.8 DDD per 1000 inhabitants per day) decreased by 5.5% compared to 2019 (28.4 DDD per 1000 inhabitants per day). There was an increase in the use of several antibiotics during 2020 compared with 2019 (third generation cephalosporins (19%), carbapenems (52%), macrolides (57%), and lincosamides (106%)). In 2020, there was a marked reduction in amoxicillin use (-53%), while the use of azithromycin increased by 74%. National antimicrobial consumption of the Access group decreased by 18% from 2019 to 2020 (59.1% vs. 48.1% of total consumption). The use of the Watch group increased in 2020 by 26%. The study highlighted an increase in the use of certain antibiotics during the pandemic period that are known to be associated with increasing resistance. Efforts to enhance national antimicrobial stewardship are needed to ensure rational use of antimicrobials.

A Review of Quality Measures for Assessing the Impact of Antimicrobial Stewardship Programs in Hospitals

The growing problem of antimicrobial resistance (AMR) has led to calls for antimicrobial stewardship programs (ASP) to control antibiotic use in healthcare settings. Key strategies include prospective audit with feedback and intervention, and formulary restriction and preauthorization. Education, guidelines, clinical pathways, de-escalation, and intravenous to oral conversion are also part of some programs. Impact and quality of ASP can be assessed using process or outcome measures. Outcome measures are categorized as microbiological, patient or financial outcomes. The objective of this review was to provide an overview of quality measures for assessing ASP and the reported impact of ASP in peer-reviewed studies, focusing particularly on patient outcomes. A literature search of papers published in English between 1990 and June 2015 was conducted in five databases using a combination of search terms. Primary studies of any design were included. A total of 63 studies were included in this review. Four studies defined quality metrics for evaluating ASP. Twenty-one studies assessed the impact of ASP on antimicrobial utilization and cost, 25 studies evaluated impact on resistance patterns and/or rate of Clostridium difficile infection (CDI). Thirteen studies assessed impact on patient outcomes including mortality, length of stay (LOS) and readmission rates. Six of these 13 studies reported non-significant difference in mortality between pre- and post-ASP intervention, and five reported reductions in mortality rate. On LOS, six studies reported shorter LOS post intervention; a significant reduction was reported in one of these studies. Of note, this latter study reported significantly (p < 0.001) higher unplanned readmissions related to infections post-ASP. Patient outcomes need to be a key component of ASP evaluation. The choice of metrics is influenced by data and resource availability. Controlling for confounders must be considered in the design of evaluation studies to adequately capture the impact of ASP and it is important for unintended consequences to be considered. This review provides a starting point toward compiling standard outcome metrics for assessing ASP.

Antibiotic use in US hospitals: quantification, quality measures and stewardship

A majority of patients hospitalized in the US hospitals receive an antibiotic during their hospitalization. Furthermore, up to half of antibiotics prescribed in hospitals are inappropriate. In the setting of continued emergence of antibiotic-resistant pathogens and a limited pipeline of new antimicrobials, attention to optimizing antibiotic use in healthcare settings is essential. We review the measures of antibiotic consumption in the USA, the evolving metrics for comparing antibiotic use (known as benchmarking), trends in antibiotic use, the structure and outcome measures of Antimicrobial Stewardship Programs and interventions to optimize antimicrobial use.