Five steps to high quality antimicrobial stewardship research.

The escalating threat of antimicrobial resistance (AMR) necessitates impactful, reproducible, and scalable antimicrobial stewardship strategies. This review addresses the critical need to enhance the quality of antimicrobial stewardship intervention research. We propose five considerations for authors planning and evaluating antimicrobial stewardship initiatives. Antimicrobial stewards should consider the following mnemonic ABCDE: (A) plan Ahead using implementation science; (B) Be clear and thoroughly describe the intervention by using the TidIER checklist; (C) Use a Checklist to comprehensively report study components; (D) Select a study Design carefully; and (E) Assess Effectiveness and implementation by selecting meaningful outcomes. Incorporating these recommendations will help strengthen the evidence base of antimicrobial stewardship literature and support optimal implementation of strategies to mitigate AMR.

Association between infectious diseases consultation and mortality in hospitalized patients with Gram-negative bloodstream infection: a retrospective population-wide cohort study.

OBJECTIVES: Data supporting routine infectious diseases (ID) consultation in Gram-negative bloodstream infection (GN-BSI) are limited. We evaluated the association between ID consultation and mortality in patients with GN-BSI in a retrospective population-wide cohort study in Ontario using linked health administrative databases. METHODS: Hospitalized adult patients with GN-BSI between April 2017 and December 2021 were included. The primary outcome was time to all-cause mortality censored at 30 days, analyzed using a mixed effects Cox proportional hazards model with hospital as a random effect. ID consultation 1-10 days after the first positive blood culture was treated as a time-varying exposure. RESULTS: Of 30,159 patients with GN-BSI across 53 hospitals, 11,013 (36.5%) received ID consultation. Median prevalence of ID consultation for patients with GN-BSI across hospitals was 35.0% with wide variability (range 2.7-76.1%, interquartile range 19.6-41.1%). 1041 (9.5%) patients who received ID consultation died within 30 days, compared to 1797 (9.4%) patients without ID consultation. In the fully-adjusted multivariable model, ID consultation was associated with mortality benefit (adjusted HR 0.82, 95% CI 0.77-0.88, p < 0.0001; translating to absolute risk reduction of -3.8% or NNT of 27). Exploratory subgroup analyses of the primary outcome showed that ID consultation could have greater benefit in patients with high-risk features (nosocomial infection, polymicrobial or non-Enterobacterales infection, antimicrobial resistance, or non-urinary tract source). CONCLUSIONS: Early ID consultation was associated with reduced mortality in patients with GN-BSI. If resources permit, routine ID consultation for this patient population should be considered to improve patient outcomes.

Confronting the Disruption of the Infectious Diseases Workforce by Artificial Intelligence: What This Means for Us and What We Can Do About It.

With the rapid advancement of artificial intelligence (AI), the field of infectious diseases (ID) faces both innovation and disruption. AI and its subfields including machine learning, deep learning, and large language models can support ID clinicians' decision making and streamline their workflow. AI models may help ensure earlier detection of disease, more personalized empiric treatment recommendations, and allocation of human resources to support higher-yield antimicrobial stewardship and infection prevention strategies. AI is unlikely to replace the role of ID experts, but could instead augment it. However, its limitations will need to be carefully addressed and mitigated to ensure safe and effective implementation. ID experts can be engaged in AI implementation by participating in training and education, identifying use cases for AI to help improve patient care, designing, validating and evaluating algorithms, and continuing to advocate for their vital role in patient care.

Documenting the indication for antimicrobial prescribing: A retrospective observational study of long-term care homes.

BACKGROUND: Overuse of antimicrobials in residents of long-term care homes is common and can result in harm. Antimicrobial stewardship interventions are needed in the long-term care (LTC) homes setting to improve the appropriate use of antimicrobials. Previous literature has highlighted the importance of documenting antimicrobial indication as a strategy that contributes to improve antimicrobial use; however, there is a lack of evidence in LTC homes. This study examines the prevalence, clarity, and facility-level variability of antibiotic indication documentation in this setting. METHODS: This is an observational retrospective study of oral antibiotic prescriptions dispensed to 218 homes between January 1, 2021 and December 31, 2022 in Ontario, Canada. Indication was obtained from reviewing antibiotic prescription data. Clarity was determined by comparing documented indication to the National Antimicrobial Prescribing Survey (NAPS). Descriptive analysis was performed to examine the prevalence and clarity of indication documentation. Funnel plots were generated to examine variability in prevalence of indication documentation and clarity at the home level. RESULTS: Overall, 22.9% (7998/34,867) of prescriptions had an indication documented. The proportion of indications that were clear was 37% (2984/7998). The most common indications were for urinary (45%), skin and soft tissue (19.9%) and respiratory infections (15.0%). At the home level, the median prevalence of indication was 19.6% (interquartile range [IQR]: 10.8%-31.4%) and median prevalence of clear indications was 35.1% (IQR: 23.8%-42.9%). Funnel plots revealed substantial variability in indication prevalence with 46.3% of homes falling outside of 99% limits but minimal variability in indication clarity between homes with only 8.7% of homes outside of 99% control limits. CONCLUSIONS: There is an opportunity to increase both the prevalence and clarity of antibiotic prescriptions in LTC homes. Future work should focus on determining how best to support prescription indication documentation in this setting with consideration being given to prescription workflow and most common antibiotic prescription indications.

Impact of extended-infusion piperacillin-tazobactam in a Canadian community hospital.

Background: Studies have demonstrated improved clinical outcomes with extended infusion (EI) piperacillin/tazobactam (TZP) compared to standard infusion (SI). However, there is less evidence on its benefits in noncritically-ill patients. Hospital-wide EI TZP was implemented at our site on February 21, 2012. Our objectives were to compare clinical, safety and economic outcomes between EI and SI TZP. Methods: A retrospective cohort study of all adult patients who received EI TZP (3.375 g IV q8h infused over 4 hours and SI TZP for ≥ 48 hours during 3 years pre-and postimplementation was conducted. The primary study outcome was 14-day mortality while secondary outcomes included length of hospital stay (LOS), nursing plus pharmacy cost, occurrence of Clostridioides difficile infection, readmission within 30 days and change in Pseudomonas aeruginosa minimum inhibitory concentration (MIC) distribution for TZP. The primary outcome and binary secondary outcomes were analyzed using a logistic regression model. LOS was examined using time to event analysis. Cost was examined using linear regression modelling. Results: Overall, 2034 patients received EI TZP and 1364 patients received SI TZP. EI TZP was associated with lower odds of mortality (OR 0.76, 95% CI 0.63-0.91), lower odds of C. difficile infection (OR 0.59, 95% CI 0.41-0.84) and 8% lower cost (estimate 0.92, 95% CI 0.87-0.98) compared to SI TZP. Conclusions: Hospital-wide implementation of EI TZP was associated with lower odds of 14-day mortality and incidence of C. difficile infection with cost savings at our institution.

Variability in changes in physician outpatient antibiotic prescribing from 2019 to 2021 during the COVID-19 pandemic in Ontario, Canada.

Objective: To evaluate inter-physician variability and predictors of changes in antibiotic prescribing before (2019) and during (2020/2021) the coronavirus disease 2019 (COVID-19) pandemic. Methods: We conducted a retrospective cohort analysis of physicians in Ontario, Canada prescribing oral antibiotics in the outpatient setting between January 1, 2019 and December 31, 2021 using the IQVIA Xponent data set. The primary outcome was the change in the number of antibiotic prescriptions between the prepandemic and pandemic period. Secondary outcomes were changes in the selection of broad-spectrum agents and long-duration (>7 d) antibiotic use. We used multivariable linear regression models to evaluate predictors of change. Results: There were 17,288 physicians included in the study with substantial inter-physician variability in changes in antibiotic prescribing (median change of -43.5 antibiotics per physician, interquartile range -136.5 to -5.0). In the multivariable model, later career stage (adjusted mean difference [aMD] -45.3, 95% confidence interval [CI] -52.9 to -37.8, p < .001), family medicine (aMD -46.0, 95% CI -62.5 to -29.4, p < .001), male patient sex (aMD -52.4, 95% CI -71.1 to -33.7, p < .001), low patient comorbidity (aMD -42.5, 95% CI -50.3 to -34.8, p < .001), and high prescribing to new patients (aMD -216.5, 95% CI -223.5 to -209.5, p < .001) were associated with decreases in antibiotic initiation. Family medicine and high prescribing to new patients were associated with a decrease in selection of broad-spectrum agents and prolonged antibiotic use. Conclusions: Antibiotic prescribing changed throughout the COVID-19 pandemic with overall decreases in antibiotic initiation, broad-spectrum agents, and prolonged antibiotic courses with inter-physician variability. These findings present opportunities for community antibiotic stewardship interventions.

Antibiotic prescribing guideline recommendations in COVID-19: a systematic survey.

Background: COVID-19 and antimicrobial resistance (AMR) are two intersecting public health crises. Antimicrobial overuse in patients with COVID-19 threatens to worsen AMR. Guidelines are fundamental in encouraging antimicrobial stewardship. We sought to assess the quality of antibiotic prescribing guidelines and recommendations in the context of COVID-19, and whether they incorporate principles of antimicrobial stewardship. Methods: We performed a systematic survey which included a search using the concepts "antibiotic/antimicrobial" up to November 15, 2022 of the eCOVID-19 living map of recommendations (RecMap) which aggregates guidelines across a range of international sources and all languages. Guidelines providing explicit recommendations regarding antibacterial use in COVID-19 were eligible for inclusion. Guideline and recommendation quality were assessed using the AGREE II and AGREE-REX instruments, respectively. We extracted guideline characteristics including panel representation and the presence or absence of explicit statements related to antimicrobial stewardship (i.e., judicious antibiotic use, antimicrobial resistance or adverse effects as a consequence of antibiotic use). We used logistic regression to evaluate the relationship between guideline characteristics including quality and incorporation of antimicrobial stewardship principles. Protocol registration (OSF): https://osf.io/4pgtc. Findings: Twenty-eight guidelines with 63 antibiotic prescribing recommendations were included. Recommendations focused on antibiotic initiation (n = 52, 83%) and less commonly antibiotic selection (n = 13, 21%), and duration of therapy (n = 15, 24%). Guideline and recommendation quality varied widely. Twenty (71%) guidelines incorporated at least one concept relating to antimicrobial stewardship. Including infectious diseases expertise on the guideline panel (OR 9.44, 97.5% CI: 1.09-81.59) and AGREE-REX score (OR 3.26, 97.5% CI: 1.14-9.31 per 10% increase in overall score) were associated with a higher odds of guidelines addressing antimicrobial stewardship. Interpretation: There is an opportunity to improve antibiotic prescribing guidelines in terms of both quality and incorporation of antimicrobial stewardship principles. These findings can help guideline developers better address antibiotic stewardship in future recommendations beyond COVID-19. Funding: This project was funded by Michael G. DeGroote Cochrane Canada and McMaster GRADE centres.

Antibiotic Selection and Duration for Catheter-Associated Urinary Tract Infection in Non-Hospitalized Older Adults: A Population-Based Cohort Study.

Background: We sought to evaluate the impact of antibiotic selection and duration of therapy on treatment failure in older adults with catheter-associated urinary tract infection (CA-UTI). Methods: We conducted a population-based cohort study comparing antibiotic treatment options and duration of therapy for non-hospitalized adults aged 66 and older with presumed CA-UTI (defined as an antibiotic prescription and an organism identified in urine culture in a patient with urinary catheterization documented within the prior 90 d). The primary outcome was treatment failure, a composite of repeat urinary antibiotic prescribing, positive blood culture with the same organism, all-cause hospitalization or mortality, within 60 days. We determined the risk of treatment failure accounting for age, sex, comorbidities, and healthcare exposure using log-binomial regression. Results: Of 4,436 CA-UTI patients, 2,709 (61.1%) experienced treatment failure. Compared to a reference of TMP-SMX (61.9% failure), of those treated with fluoroquinolones, 56.3% experienced failure (RR 0.91, 95% CI: 0.85-0.98) and 60.9% of patients treated with nitrofurantoin experienced failure (RR 1.02, 95% CI: 0.94-1.10). Compared to 5-7 days of therapy (treatment failure: 59.4%), 1-4 days was associated with 69.5% failure (RR 1.15, 95% CI: 1.05-1.27), and 8-14 days was associated with a 62.0% failure (RR 1.05, 95% CI: 0.99-1.11). Conclusions: Although most treatment options for CA-UTI have a similar risk of treatment failure, fluoroquinolones, and treatment durations ≥ 5 days in duration appear to be associated with modestly improved clinical outcomes. From a duration of therapy perspective, this study provides reassurance that relatively short courses of 5-7 days may be reasonable for CA-UTI.

Does this patient have Clostridioides difficile infection? A systematic review and meta-analysis.

BACKGROUND: The clinical features and predictors of Clostridioides difficile infection overlap with many conditions. OBJECTIVES: We performed a systematic review to evaluate the diagnostic utility of clinical features (clinical examination, risk factors, laboratory tests, and radiographic findings) associated with C. difficile. METHODS: Systematic review and meta-analysis of diagnostic features for C. difficile. DATA SOURCES: MEDLINE, EMBASE, CINAHL, and Cochrane databases were searched up to September 2021. STUDY ELIGIBILITY CRITERIA: Studies that reported clinical features of C. difficile, a valid reference standard test for confirming diagnosis of C. difficile, and a comparison among patients with a positive and negative test result. PARTICIPANTS: Adult and paediatric patients across diverse clinical settings. OUTCOMES: Sensitivity, specificity, likelihood ratios. REFERENCE STANDARD: Stool nucleic acid amplification tests, enzyme immunoassays, cell cytotoxicity assay, and stool toxigenic culture. ASSESSMENT OF RISK OF BIAS: Rational Clinical Examination Series and Quality Assessment of Diagnostic Accuracy Studies-2. METHODS OF DATA SYNTHESIS: Univariate and bivariate analyses. RESULTS: We screened 11 231 articles of which 40 were included, enabling the evaluation of 66 features for their diagnostic utility for C. difficile (10 clinical examination findings, 4 laboratory tests, 10 radiographic findings, prior exposure to 13 antibiotic types, and 29 clinical risk factors). Of the ten features identified on clinical examination, none were significantly clinically associated with increased likelihood of C. difficile infection. Some features that increased likelihood of C. difficile infection were stool leukocytes (LR+ 5.31, 95% CI 3.29-8.56) and hospital admission in the prior 3 months (LR+ 2.14, 95% CI 1.48-3.11). Several radiographic findings also strongly increased the likelihood of C. difficile infection like ascites (LR+ 2.91, 95% CI 1.89-4.49). DISCUSSION: There is limited utility of bedside clinical examination alone in detecting C. difficile infection. Accurate diagnosis of C. difficile infection requires thoughtful clinical assessment for interpretation of microbiologic testing in all suspected cases.

Evaluating a pilot, structured, face-to-face, antimicrobial stewardship, prospective audit-and-feedback program in emergency general surgery service in a community hospital.

Background: Prospective audit and feedback (PAF) is an established practice in critical care settings but not in surgical populations. We pilot-tested a structured face-to-face PAF program for our acute-care surgery (ACS) service. Methods: This was a mixed-methods study. For the quantitative analysis, the structured PAF period was from August 1, 2017, to April 30, 2019. The ad hoc PAF period was from May 1, 2019, to January 31, 2021. Interrupted time-series segmented negative binomial regression analysis was used to evaluate change in antimicrobial usage measured in days of therapy per 1,000 patient days for all systemic and targeted antimicrobials. Secondary outcomes included C. difficile infections, length of stay and readmission within 30 days. Each secondary outcome was analyzed using a logistic regression or negative binomial regression model. For the qualitative analyses, all ACS surgeons and trainees from November 23, 2015, to April 30, 2019, were invited to participate in an email-based anonymous survey developed using implementation science principles. Responses were measured using counts. Results: In total, 776 ACS patients were included in the structured PAF period and 783 patients were included in the in ad hoc PAF period. No significant changes in level or trend for antimicrobial usage were detected for all and targeted antimicrobials. Similarly, no significant differences were detected for secondary outcomes. The survey response rate was 25% (n = 10). Moreover, 50% agreed that PAF provided them with skills to use antimicrobials more judiciously, and 80% agreed that PAF improved the quality of antimicrobial treatment for their patients. Conclusion: Structured PAF showed clinical outcomes similar to ad hoc PAF. Structured PAF was well received and was perceived as beneficial by surgical staff.

Global collaborations in antimicrobial stewardship: All hands on deck.

Tackling antimicrobial resistance (AMR) through antimicrobial stewardship (AMS) interventions is a key objective within the World Health Organization (WHO)'s Global Action on AMR. We outline the reasons why global collaborations for AMS are needed. We provide examples of global collaborations, and we offer considerations when starting on a global health journey focused on AMS.

Population-based evaluation of the effectiveness of nirmatrelvir-ritonavir for reducing hospital admissions and mortality from COVID-19.

BACKGROUND: A randomized controlled trial involving a high-risk, unvaccinated population that was conducted before the Omicron variant emerged found that nirmatrelvir-ritonavir was effective in preventing progression to severe COVID-19. Our objective was to evaluate the effectiveness of nirmatrelvir-ritonavir in preventing severe COVID-19 while Omicron and its subvariants predominate. METHODS: We conducted a population-based cohort study in Ontario that included all residents who were older than 17 years of age and had a positive polymerase chain reaction test for SARS-CoV-2 between Apr. 4 and Aug. 31, 2022. We compared patients treated with nirmatrelvir-ritonavir with patients who were not treated and measured the primary outcome of hospital admission from COVID-19 or all-cause death at 1-30 days, and a secondary outcome of all-cause death. We used weighted logistic regression to calculate weighted odds ratios (ORs) with confidence intervals (CIs) using inverse probability of treatment weighting (IPTW) to control for confounding. RESULTS: The final cohort included 177 545 patients, 8876 (5.0%) who were treated with nirmatrelvir-ritonavir and 168 669 (95.0%) who were not treated. The groups were well balanced with respect to demographic and clinical characteristics after applying stabilized IPTW. We found that the occurrence of hospital admission or death was lower in the group given nirmatrelvir-ritonavir than in those who were not (2.1% v. 3.7%; weighted OR 0.56, 95% CI 0.47-0.67). For death alone, the weighted OR was 0.49 (95% CI 0.39-0.62). Our findings were similar across strata of age, drug-drug interactions, vaccination status and comorbidities. The number needed to treat to prevent 1 case of severe COVID-19 was 62 (95% CI 43-80), which varied across strata. INTERPRETATION: Nirmatrelvir-ritonavir was associated with significantly reduced odds of hospital admission and death from COVID-19, which supports use to treat patients with mild COVID-19 who are at risk for severe disease.

Antimicrobial resistance in patients with COVID-19: a systematic review and meta-analysis.

BACKGROUND: Frequent use of antibiotics in patients with COVID-19 threatens to exacerbate antimicrobial resistance. We aimed to establish the prevalence and predictors of bacterial infections and antimicrobial resistance in patients with COVID-19. METHODS: We did a systematic review and meta-analysis of studies of bacterial co-infections (identified within ≤48 h of presentation) and secondary infections (>48 h after presentation) in outpatients or hospitalised patients with COVID-19. We searched the WHO COVID-19 Research Database to identify cohort studies, case series, case-control trials, and randomised controlled trials with populations of at least 50 patients published in any language between Jan 1, 2019, and Dec 1, 2021. Reviews, editorials, letters, pre-prints, and conference proceedings were excluded, as were studies in which bacterial infection was not microbiologically confirmed (or confirmed via nasopharyngeal swab only). We screened titles and abstracts of papers identified by our search, and then assessed the full text of potentially relevant articles. We reported the pooled prevalence of bacterial infections and antimicrobial resistance by doing a random-effects meta-analysis and meta-regression. Our primary outcomes were the prevalence of bacterial co-infection and secondary infection, and the prevalence of antibiotic-resistant pathogens among patients with laboratory-confirmed COVID-19 and bacterial infections. The study protocol was registered with PROSPERO (CRD42021297344). FINDINGS: We included 148 studies of 362 976 patients, which were done between December, 2019, and May, 2021. The prevalence of bacterial co-infection was 5·3% (95% CI 3·8-7·4), whereas the prevalence of secondary bacterial infection was 18·4% (14·0-23·7). 42 (28%) studies included comprehensive data for the prevalence of antimicrobial resistance among bacterial infections. Among people with bacterial infections, the proportion of infections that were resistant to antimicrobials was 60·8% (95% CI 38·6-79·3), and the proportion of isolates that were resistant was 37·5% (26·9-49·5). Heterogeneity in the reported prevalence of antimicrobial resistance in organisms was substantial (I2=95%). INTERPRETATION: Although infrequently assessed, antimicrobial resistance is highly prevalent in patients with COVID-19 and bacterial infections. Future research and surveillance assessing the effect of COVID-19 on antimicrobial resistance at the patient and population level are urgently needed. FUNDING: WHO.

Antimicrobial resistance and mortality following E. coli bacteremia.

Background: Global estimates suggest millions of deaths annually are associated with antimicrobial resistance (AMR) but these are generated from scarce data on the relative risk of death attributable to drug-resistant versus drug-sensitive infections. Methods: We examined all episodes of E. coli bloodstream infection in Ontario, Canada between 2017 and 2020, and measured 90 day mortality among those with resistant versus sensitive isolates for each of 8 commonly used antibiotic classes and a category of difficult to treat resistance (DTTR). We used multivariable logistic regression to calculate an adjusted odds of mortality associated with AMR, after accounting for patient demographics, comorbidities, and prior healthcare exposure. Findings: Among 14,548 eligible episodes of E. coli bloodstream infection, resistance was most common to aminopenicillins (46.8%), followed by first generation cephalosporins (38.8%), fluoroquinolones (26.5%), sulfonamides (24.1%), third generation cephalosporins (13.8%), aminoglycosides (11.7%), beta-lactam-beta-lactamase-inhibitors (9.1%) and carbapenems (0.2%). Only 18 (0.1%) episodes exhibited DTTR. For each antibiotic class, the unadjusted odds of mortality (OR) were higher among resistant isolates, but after accounting for patient characteristics the adjusted odds (aOR) of mortality were attenuated: aminopenicillins (OR 1.22, 95% CI 1.12-1.33; aOR 1.09, 95% CI 0.99-1.20), first generation cephalosporins (OR 1.24, 95% CI 1.14-1.35; aOR 1.07, 95% CI 0.97-1.18), third generation cephalosporins (OR 1.64, 95% CI 1.47-1.82; aOR 1.29, 95% CI 1.15-1.46), beta-lactam-beta-lactamase-inhibitors (OR 1.69, 95% CI 1.52-1.89, aOR 1.28, 95% CI 1.13-1.45), carbapenems (OR 3.11, 95% CI 1.52-6.34; aOR 2.06, 95% CI 0.91-4.66), sulfonamides (OR 1.19, 95% CI 1.07-1.31, aOR 1.06, 95% CI 0.95-1.18), fluoroquinolones (OR 1.49, 95% CI 1.36-1.64, aOR 1.16, 95% CI 1.05-1.29), aminoglycosides (OR 1.43, 95% CI 1.27-1.62; aOR 1.27, 95% CI 1.11-1.46), and DTTR (OR 3.71, 95% CI 1.46-9.41; aOR 2.58, 95% CI 0.87-7.66). Interpretation: AMR is associated with substantial increased mortality among patients with E. coli bloodstream infection, particularly for resistance to classes commonly used as empiric treatment. Surveillance for AMR-associated mortality should incorporate adjustment for patient characteristics and prior healthcare utilization. Funding: This work was supported by a project grant from CIHR (grant number 159503). This study was also supported by ICES, which is funded by an annual grant from Ontario Ministry of Health and Long-Term Care (MOHLTC).

A cross-sectional study of hospital antimicrobial stewardship programmes in the COVID-19 era.

Background: Antimicrobial resistance (AMR) continues to be a global public health issue amid the COVID-19 pandemic; however, unprecedented demands on hospital antimicrobial stewardship programmes (ASPs) potentially altered their core activities. Objective: We sought to understand how ASPs have been involved in and impacted by the pandemic. Methods: The 2021 Ontario ASP Landscape Survey was developed based on previous provincial questionnaires and emerging literature on the impact of COVID-19 on hospital ASPs. After pre-testing and piloting, the online questionnaire was distributed to hospital antimicrobial stewardship practitioners in the fall of 2021. Descriptive statistics and inductive thematic analysis were performed. Results: The response rate was 78% (98/125 organizations); 96% (94/98) of organizations had or were in the process of formalizing an ASP and 53% (50/94) reported designated funding/resources. Despite 82% reporting no change in dedicated full-time equivalents during the pandemic, ASPs were frequently involved in developing treatment guidelines/clinical pathways (51%), anticipating/managing drug shortages (46%) and obtaining investigational use drugs (32%). While many core ASP activities continued, prospective audit and feedback and prescriber education were modified or suspended by 43% and 40% of programmes, respectively. Decreased frequency, adaptation of activities (i.e. virtual or other technology) and challenges with staffing/resources were commonly reported themes. Knowledge translation (KT) activities and 'collaboration and coordination' also emerged as salient themes. Conclusions: Hospital antimicrobial stewardship practitioners in Ontario have made significant contributions to the pandemic response while continuing to deliver adapted ASP services, despite resource constraints. Moving forward, ASPs will need to continue building capacity while leveraging broader networks to advance the antimicrobial stewardship agenda.