Sustained Reductions in Overall and Unnecessary Antibiotic Prescribing at Primary Care Clinics in a Veterans Affairs Healthcare System Following a Multifaceted Stewardship Intervention

A five-year quasi-experimental study to evaluate the impact of empiric antibiotic order sets on antibiotic use metrics among hospitalized adult patients

OBJECTIVE

Evaluation of adult antibiotic order sets (AOSs) on antibiotic stewardship metrics has been limited. The primary outcome was to evaluate the standardized antimicrobial administration ratio (SAAR). Secondary outcomes included antibiotic days of therapy (DOT) per 1,000 patient days (PD); selected antibiotic use; AOS utilization; Clostridioides difficile infection (CDI) cases; and clinicians' perceptions of the AOS via a survey following the final study phase.

DESIGN

This 5-year, single-center, quasi-experimental study comprised 5 phases from 2017 to 2022 over 10-month periods between August 1 and May 31.

SETTING

The study was conducted in a 752-bed tertiary care, academic medical center.

INTERVENTION

Our institution implemented AOSs in the electronic medical record (EMR) for common infections among hospitalized adults.

RESULTS

For the primary outcome, a statistically significant decreases in SAAR were detected from phase 1 to phase 5 (1.0 vs 0.90; P < .001). A statistically significant decreases were detected in DOT per 1,000 PD (4,884 vs 3,939; P = .001), fluoroquinolone orders (407 vs 175; P < .001), carbapenem orders (147 vs 106; P = .024), and clindamycin orders (113 vs 73; P = .01). No statistically significant change in mean vancomycin orders was detected (991 vs 902; P = .221). A statistically significant decrease in CDI cases was also detected (7.8, vs 2.4; P = .002) but may have been attributable to changes in CDI case diagnosis. Clinicians indicated that the AOSs were easy to use overall and that they helped them select the appropriate antibiotics.

CONCLUSIONS

Implementing AOS into the EMR was associated with a statistically significant reduction in SAAR, antibiotic DOT per 1,000 PD, selected antibiotic orders, and CDI cases.

Clostridioides difficile Infection in Hospitalized Patients-A Retrospective Epidemiological Study

Clostridioides difficile infection (CDI) is the main source of healthcare and antibiotic-associated diarrhea in hospital context and long-term care units, showing significant morbidity and mortality. This study aimed to analyze the epidemiological context, describing the severity and outcomes of this event in patients admitted to our hospital, thus confirming the changing global epidemiological trends in comparison with other cohorts. We conducted a single-center, observational, and retrospective study at the Hospital do Espírito Santo (HESE), Évora, in Portugal, analyzing the incidence of CDI in patients meeting eligibility criteria from January to December 2018. During this period, an annual incidence rate of 20.7 cases per 10,000 patients was documented. The studied population average age was 76.4 ± 12.9 years, 83.3% over 65. Most episodes were healthcare-acquired, all occurring in patients presenting multiple risk factors, with recent antibiotic consumption being the most common. Regarding severity, 23.3% of cases were classified as severe episodes. Recurrences affected 16.7% of participants, predominantly female patients over 80 years old, all of whom were healthcare-acquired. Mortality rate was disproportionately high among the older population. Our investigation documented an overall incidence rate of over 10.4-fold the number of cases identified in the year 2000 at the same hospital, more recently and drastically, in community-associated episodes.

Next Steps in Ambulatory Stewardship

Most antibiotics are prescribed in ambulatory setting and at least 30% to 50% of these prescriptions are unnecessary. The use of antibiotics when not needed promotes the development of antibiotic resistant organisms and harms patients by placing them at risk for adverse drug events and Clostridioides difficile infections. National guidelines recommend that health systems implement antibiotic stewardship programs in ambulatory settings. However, uptake of stewardship in ambulatory setting has remained low. This review discusses the current state of ambulatory stewardship in the United States, best practices for the successful implementation of effective ambulatory stewardship programs, and future directions to improve antibiotic use in ambulatory settings.

Implementation and outcomes of a clinician-directed intervention to improve antibiotic prescribing for acute respiratory tract infections within the Veterans' Affairs Healthcare System

OBJECTIVE

To determine whether a clinician-directed acute respiratory tract infection (ARI) intervention was associated with improved antibiotic prescribing and patient outcomes across a large US healthcare system.

DESIGN

Multicenter retrospective quasi-experimental analysis of outpatient visits with a diagnosis of uncomplicated ARI over a 7-year period.

PARTICIPANTS

Outpatients with ARI diagnoses: sinusitis, pharyngitis, bronchitis, and unspecified upper respiratory tract infection (URI-NOS). Outpatients with concurrent infection or select comorbid conditions were excluded.

INTERVENTION(S)

Audit and feedback with peer comparison of antibiotic prescribing rates and academic detailing of clinicians with frequent ARI visits. Antimicrobial stewards and academic detailing personnel delivered the intervention; facility and clinician participation were voluntary.

MEASURE(S)

We calculated the probability to receive antibiotics for an ARI before and after implementation. Secondary outcomes included probability for a return clinic visits or infection-related hospitalization, before and after implementation. Intervention effects were assessed with logistic generalized estimating equation models. Facility participation was tracked, and results were stratified by quartile of facility intervention intensity.

RESULTS

We reviewed 1,003,509 and 323,023 uncomplicated ARI visits before and after the implementation of the intervention, respectively. The probability to receive antibiotics for ARI decreased after implementation (odds ratio [OR], 0.82; 95% confidence interval [CI], 0.78-0.86). Facilities with the highest quartile of intervention intensity demonstrated larger reductions in antibiotic prescribing (OR, 0.69; 95% CI, 0.59-0.80) compared to nonparticipating facilities (OR, 0.89; 95% CI, 0.73-1.09). Return visits (OR, 1.00; 95% CI, 0.94-1.07) and infection-related hospitalizations (OR, 1.21; 95% CI, 0.92-1.59) were not different before and after implementation within facilities that performed intensive implementation.

CONCLUSIONS

Implementation of a nationwide ARI management intervention (ie, audit and feedback with academic detailing) was associated with improved ARI management in an intervention intensity-dependent manner. No impact on ARI-related clinical outcomes was observed.

Antimicrobial stewardship intervention bundle decreases outpatient fluoroquinolone prescribing for urinary tract infections

An antimicrobial stewardship bundle was implemented in 23 community health system urgent care and primary care clinics to reduce fluoroquinolone prescribing in urinary tract infections. The percentage of urinary tract infection (UTI) visits prescribed a fluoroquinolone subsequently decreased from 17.6% to 3% in urgent care and from 23.8% to 6.8% in primary care.

A multimodal intervention to decrease inappropriate outpatient antibiotic prescribing for upper respiratory tract infections in a large integrated healthcare system

OBJECTIVE

To evaluate the effectiveness of Carolinas Healthcare Outpatient Antimicrobial Stewardship Empowerment Network (CHOSEN), a multicomponent outpatient stewardship program to reduce inappropriate antibiotic prescribing for upper respiratory infections by 20% over 2 years.

DESIGN

Before-and-after interrupted time series of antibiotics prescribed between 2 periods: April 2016-October 2017 and May 2018-March 2020.

SETTING

The study included 162 primary-care practices within a large healthcare system in the greater Charlotte, North Carolina region.

PARTICIPANTS

Adult and pediatric patients with encounters for upper respiratory infections for which an antibiotic is inappropriate.

METHODS

Patient and provider educational materials, along with a web-based provider prescribing dashboard aimed at reducing inappropriate antibiotic prescribing were developed and distributed. Monthly antibiotic prescribing rates were calculated as the number of eligible encounters with an antibiotic prescribed divided by the total number of eligible encounters. A segmented regression analysis compared monthly antibiotic prescribing rates before versus after CHOSEN implementation, while also accounting for practice type and seasonal trends in prescribing.

RESULTS

Overall, 286,580 antibiotics were prescribed during 704,248 preintervention encounters and 277,177 during 832,200 intervention encounters. Significant reductions in inappropriate prescribing rates were observed in all outpatient specialties: family medicine (relative difference before and after the intervention, -20.4%), internal medicine (-19.5%), pediatric medicine (-17.2%), and urgent care (-16.6%).

CONCLUSIONS

A robust multimodal intervention that combined a provider prescribing dashboard with a targeted education campaign demonstrated significant decreases in inappropriate outpatient antibiotic prescribing for upper respiratory tract infections in a large integrated ambulatory network.

The impact of COVID-19 on multidrug-resistant organisms causing healthcare-associated infections: a narrative review

Coronavirus disease 2019 (COVID-19) changed healthcare across the world. With this change came an increase in healthcare-associated infections (HAIs) and a concerning concurrent proliferation of MDR organisms (MDROs). In this narrative review, we describe the impact of COVID-19 on HAIs and MDROs, describe potential causes of these changes, and discuss future directions to combat the observed rise in rates of HAIs and MDRO infections.

Effects of social norm feedback on antibiotic prescribing and its characteristics in behaviour change techniques: a mixed-methods systematic review

Low-cost and low-barrier antibiotic stewardship strategies are urgently needed to deal with the widespread problem of antibiotic resistance. Social norm feedback could be a promising strategy. In this mixed-methods systematic review (PROSPERO: CRD42022361039), we aimed to identify the key behaviour change techniques used in social norm feedback for antibiotic stewardship and assess their effectiveness in reducing antibiotic prescribing. We searched PubMed, Embase, Web of Science, and Scopus for peer-reviewed studies published between Jan 1, 2000, and Jan 20, 2022. 3547 studies were screened, of which 23 studies reporting the effects of social norm feedback interventions on antibiotic prescribing met the inclusion criteria. 19 behaviour change techniques were tested in the included studies. The meta-analyses showed that social norm feedback is an effective strategy for reducing antibiotic prescribing, with an overall rate difference of 4% (p<0·0001). The behaviour change technique with the highest effective ratio (ER=13) was information about health consequences, followed by instruction on how to perform the behaviour (ER=9) and adding objects to the environment (ER=9). Social norm feedback is a promising strategy to reduce antibiotic prescribing, and can be incorporated into the clinical decision-making support system.

Identification of priority targets for intervention in outpatient antimicrobial stewardship

A multimodal antimicrobial stewardship intervention was associated with a decrease in antibiotic prescribing for targeted non-coronavirus disease 2019 (COVID-19) upper respiratory infections from 27.6% in 2019 to 7.6% in 2021. We describe our approach to prioritizing departments for 3 levels of interventions in the setting of limited stewardship personnel.

Ambulatory Fluoroquinolone Use in the United States, 2015-2019

Background

Frequently used fluoroquinolones have been subject to increasing safety concerns and regulatory alerts. This study characterized ambulatory fluoroquinolone utilization in the United States and evaluated the impact of 2016 Food and Drug Administration (FDA) safety advisories on its use.

Methods

We used IQVIA's National Disease and Therapeutic Index to quantify adult outpatient fluoroquinolone use ("treatment visits"). Descriptive statistics and segmented regression were used to report trends and quantify the varied use before and after FDA's 2016 alerts.

Results

Between 2015 to 2019, fluoroquinolone use decreased by 26.7% (18.7 million treatment visits in 2015 to 13.7 million treatment visits in 2019). Annual use declined by 44%, 24%, and 24% for respiratory, urogenital, and gastrointestinal conditions, respectively; and by 66% among providers ≤44 years old vs negligible decline among those ≥65 years old. Before 2016 FDA advisories, there were approximately 4.8 million fluoroquinolone treatment visits/quarter, which had a statistically significant immediate drop by 641035 visits (95% confidence interval [CI], -937368 to -344702; P=.000) after FDA's 2016 advisories. A statistically significant difference of approximately 45000 visits/quarter (95% CI, -85956 to -3122; P=.036) was observed after the advisories.

Conclusions

Large reductions in ambulatory fluoroquinolone use in the United States have coincided with increasing evidence of safety concerns and FDA advisories. However, fluoroquinolone use varies significantly based on patient and provider characteristics, suggesting heterogeneous effects of emerging risks on clinical practice.

Infectious diseases experts as part of the antibiotic stewardship team in primary care: protocol for a cluster-randomised blinded study (IDASP)

INTRODUCTION

Antibiotic overuse is directly related to antibiotic resistance, and primary care is one of the main reasons for this overuse. This study aims to demonstrate that including experts on infectious diseases (ID) within the antimicrobial stewardship (AMS) programme team in primary care settings achieves higher reductions in overall antibiotic consumption and increases the quality of prescription.

METHODS AND ANALYSIS

A multicentre, cluster-randomised, blinded clinical trial will be conducted between 2021 and 2023. Six primary care centres will be randomly assigned to an advanced or a standard AMS programme. The advanced AMS programme will consist of a standard AMS programme combined with the possibility that general practitioners (GP) will discuss patients' therapies with ID experts telephonically during working days and biweekly meetings. The main endpoint will be overall antibiotic consumption, defined as daily defined dose per 1000 inhabitants per day (DHD). Secondary end-points will be: (1) unnecessary antibiotic prescriptions in patients diagnosed with upper respiratory tract or urinary tract infection, (2) adequacy of antibiotic prescription, (3) reattendance to GP or emergency room within 30 days after the initial GP visit and (4) hospital admissions for any reason within 30 days after the GP visit. Two secondary endpoints (unnecessary antibiotic therapy and adequacy of therapy) will be evaluated by blinded investigators.We will select three clusters (centres) per arm (coverage of 147 644 inhabitants) which will allow the rejection of the null hypothesis of equal consumption with a power of 80%, assuming a moderate intracluster correlation of 0.2, an intracluster variance of 4 and a mean difference of 1 DHD. The type I error will be set at 5%.

ETHICS AND DISSEMINATION

The protocol was reviewed and approved by local ethics committees. The results of this study will be published in peer-reviewed journals and presented at medical conferences.

TRIAL REGISTRATION NUMBER

NCT04848883.

Improving Outpatient Antibiotic Prescribing for Respiratory Tract Infections in Primary Care; a Stepped-Wedge Cluster Randomized Trial

BACKGROUND

Inappropriate antibiotic prescribing is common in primary care (PC), particularly for respiratory tract diagnoses (RTDs). However, the optimal approach for improving prescribing remains unknown.

METHODS

We conducted a stepped-wedge study in PC practices within a health system to assess the impact of a provider-targeted intervention on antibiotic prescribing for RTDs. RTDs were grouped into tiers based on appropriateness of antibiotic prescribing: tier 1 (almost always indicated), tier 2 (may be indicated), and tier 3 (rarely indicated). Providers received education on appropriate RTD prescribing followed by monthly peer comparison feedback on antibiotic prescribing for (1) all tiers and (2) tier 3 RTDs. Chi-squared testing was used to compare the proportion of visits with antibiotic prescriptions before and during the intervention. Mixed-effects multivariable logistic regression analysis was performed to assess the association between the intervention and antibiotic prescribing.

RESULTS

Across 30 PC practices and 185,755 total visits, overall antibiotic prescribing was reduced with the intervention, from 35.2% to 23.0% of visits (p<0.001). In multivariable analysis, the intervention was associated with a reduced odds of antibiotic prescription for tiers 2 (OR 0.57; 95% CI 0.52 - 0.62) and 3 (OR 0.57; 95% CI 0.53 - 0.61), but not for tier 1 (OR 0.98; 95% CI 0.83 - 1.16).

CONCLUSION

A provider-focused intervention reduced overall antibiotic prescribing for RTDs without affecting prescribing for infections that likely require antibiotics. Future research should examine the sustainability of such interventions, potential unintended adverse effects on patient health or satisfaction, and provider perceptions and acceptability.

Operationalising outpatient antimicrobial stewardship to reduce system-wide antibiotics for acute bronchitis

BACKGROUND

Antibiotics are not recommended for treatment of acute uncomplicated bronchitis (AUB), but are often prescribed (85% of AUB visits within the Veterans Affairs nationally). This quality improvement project aimed to decrease antibiotic prescribing for AUB in community-based outpatient centres from 65% to <32% by April 2020.

METHODS

From January to December 2018, community-based outpatient clinics' 6 months' average of prescribed antibiotics for AUB and upper respiratory infections was 63% (667 of 1054) and 64.6% (314 of 486) when reviewing the last 6 months. Seven plan-do-study-act (PDSA) cycles were implemented by an interprofessional antimicrobial stewardship team between January 2019 and March 2020. Balancing measures were a return patient phone call or visit within 4 weeks for the same complaint. Χ² tests and statistical process control charts using Western Electric rules were used to analyse intervention data.

RESULTS

The AUB antibiotic prescribing rate decreased from 64.6% (314 of 486) in the 6 months prior to the intervention to 36.8% (154 of 418) in the final 6 months of the intervention. No change was seen in balancing measures. The largest reduction in antibiotic prescribing was seen after implementation of PDSA 6 in which 14 high prescribers were identified and targeted for individualised reviews of encounters of patients with AUB with an antimicrobial steward.

CONCLUSIONS

Operational implementation of successful stewardship interventions is challenging and differs from the traditional implementation study environment. As a nascent outpatient stewardship programme with limited resources and no additional intervention funding, we successfully reduced antibiotic prescribing from 64.6% to 36.8%, a reduction of 43% from baseline. The most success was seen with targeted education of high prescribers.

Outpatient Fluoroquinolone Prescription Fills in the United States, 2014 to 2020: Assessing the Impact of Food and Drug Administration Safety Warnings

The impact of United States Food and Drug Administration (FDA) safety warnings on outpatient fluoroquinolone use is unclear. Annual changes in outpatient ciprofloxacin, levofloxacin, and moxifloxacin prescription fills (IQVIA National Prescription Audit databases) were assessed using a regression model. Monthly fills during baseline (August 2014 to April 2016) and first (May 2016 to June 2018) and second FDA warning periods (July 2018 to February 2020) were compared by interrupted time series analysis. From 2015 through 2019, total fluoroquinolone fills decreased from 35,616,786 (111.1/1,000 persons) to 21,100,050 (64.3/1,000 persons) annually (10.8% annually [P = 0.001]). Ciprofloxacin, levofloxacin, and moxifloxacin fills decreased annually by 10.4% (P = 0.001), 11.2% (P < 0.001), and 17.7% (P = 0.008), respectively. During the baseline period, there was no significant change in monthly fluoroquinolone fills. In May 2016 and during the first warning period, monthly fluoroquinolone fills decreased significantly (P < 0.001); the trend of decreased fills was significantly greater than that of the baseline period (P = 0.02). There was no change in fluoroquinolone fills in July 2018. Monthly fills decreased significantly throughout the second warning period (P < 0.001), but the trend did not differ from that of the first warning period. Trends for ciprofloxacin, the most commonly prescribed fluoroquinolone, were similar to those for the class. Fills of prescriptions by infectious diseases specialists (P < 0.005) and nurse practitioners (P = 0.04) significantly increased during the study. U.S. outpatient fluoroquinolone prescription fills significantly decreased from August 2014 to February 2020, most strongly in association with May 2016 FDA warnings. FDA safety warnings are useful tools for leveraging outpatient antimicrobial stewardship.

Appropriateness of Antibiotic Prescribing for Acute Sinusitis in Primary Care: A Cross-sectional Study

The proportion of sinusitis visits that meet antibiotic prescribing criteria is unknown. Of 425 randomly selected sinusitis visits, 50% (214) met antibiotic prescribing criteria. There was no significant difference in antibiotic prescribing at visits that did (205/214 [96%]) and did not (193/211 [92%]; P = .07) meet antibiotic prescribing criteria.

Using Audit and Feedback to Improve Antimicrobial Prescribing in Emergency Departments: A Multicenter Quasi-Experimental Study in the Veterans Health Administration

Background

In this pilot trial, we evaluated whether audit-and-feedback was a feasible strategy to improve antimicrobial prescribing in emergency departments (EDs).

Methods

We evaluated an audit-and-feedback intervention using a quasi-experimental interrupted time-series design at 2 intervention and 2 matched-control EDs; there was a 12-month baseline, 1-month implementation, and 11-month intervention period. At intervention sites, clinicians received (1) a single, one-on-one education about antimicrobial prescribing for common infections and (2) individualized feedback on total and condition-specific (uncomplicated acute respiratory infection [ARI]) antimicrobial use with peer-to-peer comparisons at baseline and every quarter. The primary outcome was the total antimicrobial-prescribing rate for all visits and was assessed using generalized linear models. In an exploratory analysis, we measured antimicrobial use for uncomplicated ARI visits and manually reviewed charts to assess guideline-concordant management for 6 common infections.

Results

In the baseline and intervention periods, intervention sites had 28 016 and 23 164 visits compared to 33 077 and 28 835 at control sites. We enrolled 27 of 31 (87.1%) eligible clinicians; they acknowledged receipt of 33.3% of feedback e-mails. Intervention sites compared with control sites had no absolute reduction in their total antimicrobial rate (incidence rate ratio = 0.99; 95% confidence interval, 0.98-1.01). At intervention sites, antimicrobial use for uncomplicated ARIs decreased (68.6% to 42.4%; P < .01) and guideline-concordant management improved (52.1% to 72.5%; P < .01); these improvements were not seen at control sites.

Conclusions

At intervention sites, total antimicrobial use did not decrease, but an exploratory analysis showed reduced antimicrobial prescribing for viral ARIs. Future studies should identify additional targets for condition-specific feedback while exploring ways to make electronic feedback more acceptable.

Decreased Overall and Inappropriate Antibiotic Prescribing in a Veterans Affairs Hospital Emergency Department following a Peer Comparison-Based Stewardship Intervention

Antibiotic prescribing is very common in emergency departments (EDs). Optimal stewardship intervention strategies in EDs are not well defined. We conducted a prospective, observational cohort study in a Veterans Affairs ED in which clinician education and monthly e-mail-based peer comparisons were directed against all oral antibiotic prescribing for discharged patients. Oral antibiotic prescriptions were compared in baseline (June 2016 to December 2017) and intervention (January to June 2018) periods using an interrupted time series regression model. Prescribing appropriateness was compared during January to June 2017 and the intervention period. During the intervention period, antibiotic prescriptions decreased monthly by 10.4 prescriptions per 1,000 ED visits (P = 0.07 [95% confidence interval {CI}, -21.7 to 1.0]). The relative decrease in the trend of antibiotic prescriptions during the intervention period compared to baseline was 9.9 prescriptions per 1,000 ED visits per month (P = 0.07 [95% CI, -20.9 to 1.0]). The intervention was associated with a significant decrease and increase in amoxicillin-clavulanate and cephalexin prescriptions, respectively (P < 0.001, P = 0.004). Decreasing trends in ciprofloxacin prescriptions during the baseline period were maintained during the intervention. Unnecessary antibiotic prescribing (i.e., antibiotic not indicated) decreased from 55.6% to 38.7% during the intervention (30.4% decrease, P = 0.003). Optimal antibiotic prescribing (i.e., antibiotics were indicated, and a guideline-concordant agent was prescribed for guideline-concordant duration) increased by 36% (21.6% to 29.3%, P = 0.12). A peer comparison-based stewardship intervention directed at ED clinicians was associated with reductions in overall and unnecessary oral antibiotic prescribing. There is potential to further improve antibiotic use as suboptimal prescribing remained common.

One Health in hospitals: how understanding the dynamics of people, animals, and the hospital built-environment can be used to better inform interventions for antimicrobial-resistant gram-positive infections

Despite improvements in hospital infection prevention and control, healthcare associated infections (HAIs) remain a challenge with significant patient morbidity, mortality, and cost for the healthcare system. In this review, we use a One Health framework (human, animal, and environmental health) to explain the epidemiology, demonstrate key knowledge gaps in infection prevention policy, and explore improvements to control Gram-positive pathogens in the healthcare environment. We discuss patient and healthcare worker interactions with the hospital environment that can lead to transmission of the most common Gram-positive hospital pathogens – methicillin-resistant Staphylococcus aureus, Clostridioides (Clostridium) difficile, and vancomycin-resistant Enterococcus – and detail interventions that target these two One Health domains. We discuss the role of animals in the healthcare settings, knowledge gaps regarding their role in pathogen transmission, and the absence of infection risk mitigation strategies targeting animals. We advocate for novel infection prevention and control programs, founded on the pillars of One Health, to reduce Gram-positive hospital-associated pathogen transmission.

Successful improvement of antibiotic prescribing at Primary Care in Andalusia following the implementation of an antimicrobial guide through multifaceted interventions: An interrupted time-series analysis

BACKGROUND

Most effective strategies designed to improve antimicrobial prescribing have multiple approaches. We assessed the impact of the implementation of a rigorous antimicrobial guide and subsequent multifaceted interventions aimed at improving antimicrobial use in Primary Care.

METHODS

A quasi-experimental study was designed. Interventions aimed at achieving a good implementation of the guide consisted of the development of electronic decision support tools, local training meetings, regional workshops, conferences, targets for rates of antibiotic prescribing linked to financial incentives, feedback on antibiotic prescribing, and the implementation of a structured educational antimicrobial stewardship program. Interventions started in 2011, and continued until 2018. Outcomes: rates of antibiotics use, calculated into defined daily doses per 1,000 inhabitants-day (DID). An interrupted time-series analysis was conducted. The study ran from January 2004 until December 2018.

RESULTS

Overall annual antibiotic prescribing rates showed increasing trends in the pre-intervention period. Interventions were followed by significant changes on trends with a decline over time in antibiotic prescribing. Overall antibiotic rates dropped by 28% in the Aljarafe Area and 22% in Andalusia between 2011 and 2018, at rates of -0.90 DID per year (95%CI:-1.05 to -0.75) in Aljarafe, and -0.78 DID (95%CI:-0.95 to -0.60) in Andalusia. Reductions occurred at the expense of the strong decline of penicillins use (33% in Aljarafe, 25% in Andalusia), and more precisely, amoxicillin clavulanate, whose prescription plummeted by around 50%. Quinolones rates decreased before interventions, and continued to decline following interventions with more pronounced downward trends. Decreasing cephalosporins trends continued to decline, at a lesser extent, following interventions in Andalusia. Trends of macrolides rates went from a downward trend to an upward trend from 2011 to 2018.

CONCLUSIONS

Multifaceted interventions following the delivering of a rigorous antimicrobial guide, maintained in long-term, with strong institutional support, could led to sustained reductions in antibiotic prescribing in Primary Care.