Impact of antimicrobial stewardship programme changes on unnecessary double anaerobic coverage therapy

"Antimicrobial utilization in a paediatric intensive care unit in India: A step towards strengthening antimicrobial stewardship practices"

Antimicrobials are frequently used in critically ill children admitted to the Paediatric Intensive Care Unit (PICU). The antimicrobial use data from Indian PICUs is limited using standard metrics such as Days of therapy (DOT). This study aimed to determine the baseline trend of antimicrobial use in PICU of a tertiary care teaching hospital of Raipur district of Chhattisgarh, India using standard metrics with the goal of developing facility-wide antibiotic policy and strengthening the antimicrobial stewardship activities. This active surveillance was conducted over a period of 18 months, from November 1, 2019, to March 21, 2021, in patients aged one month to 14 years who were admitted for ≥ 48 hours to the PICU at a tertiary care teaching hospital of Raipur District. Data on patient characteristics, antimicrobial indications, antimicrobial prescription information, and clinical outcomes were collected using pre-designed data abstraction forms. The descriptive statistic was used to represent the results. The antimicrobial consumption was analyzed according to the WHO AWaRe Class (Access, Watch, and Reserve groups) of antibiotics. The antimicrobial consumption was expressed as DOT/1000 patient-days (PD). A total of 216 patients were surveyed during the study period. The average number of antimicrobials prescribed per hospitalisation was 2.60 (range: 1-12), with 97.22% administered via parenteral route. Overall, DOT/1000-PD was 1318. The consumption of Watch Group antimicrobials was highest with 949 DOT/1000-PD, followed by Access (215) and Reserve Group (154), respectively. Ceftriaxone (208 DOT/1000 PD) was the most commonly prescribed antimicrobial agent, followed by Vancomycin (201), Meropenem (175), Piperacillin-Tazobactam (122) and Colistin (91). The patients who were escalated (28.24%) from empirical antimicrobial therapy had longer median PICU stay (8 days) compared those who were de-escalated (23.6%). Targeted therapy was given in 10.2% patients. The overall mortality rate was 14.35% and was higher (29.3%) in patients in whom empirical therapy was escalated compared to those who were de-escalated or continued. The study established a benchmark for antimicrobials use in the PICU and highlighted priority areas for antimicrobial stewardship intervention to enhance de-escalation rates, enhance targeted therapy, and reduce the overuse of antimicrobials especially belonging to the reserve group.

Impact of Antibiotic Authorisation at Three Provincial Hospitals in Thailand: Results from a Quasi-Experimental Study

Implementing antimicrobial stewardship (AMS) at non-university hospitals is challenging. A quasi-experimental study was conducted to determine the impact of customised antibiotic authorisation implementation on antimicrobial consumption and clinical outcomes at three provincial hospitals in Thailand. Customised pre-authorisation of selected restricted antibiotics and post-authorisation of selected controlled antibiotics were undertaken and implemented at each hospital by the local AMS team with guidance from the AMS team at the university hospital. From January 2019−December 2020, there were 1802 selected patients (901 patients during the pre-implementation period and 901 patients during the post-implementation period). The most commonly used targeted antimicrobial was meropenem (49.61%), followed by piperacillin/tazobactam (36.46%). Comparison of the outcomes of the patients during the pre- and post-implementation periods revealed that the mean day of therapy of the targeted antimicrobials was significantly shorter during the post-implementation period (6.24 vs. 7.64 days; p < 0.001), the favourable clinical response (the improvement in all clinical and laboratory parameters at the end of antibiotic therapy) was significantly higher during the post-implementation period (72.70% vs. 68.04%; p = 0.03) and the mean length of hospital stay was significantly shorter during the post-implementation period (15.78 vs. 18.90 days; p < 0.001). In conclusion, implementation of antibiotic authorisation at provincial hospitals under experienced AMS team’s guidance was feasible and useful. The study results could be a good model for the implementation of customised AMS strategies at other hospitals with limited resources.

Association of Exposure to High-risk Antibiotics in Acute Care Hospitals With Multidrug-Resistant Organism Burden in Nursing Homes

IMPORTANCE

Little is known about the contribution of hospital antibiotic prescribing to multidrug-resistant organism (MDRO) burden in nursing homes (NHs).

OBJECTIVES

To characterize antibiotic exposures across the NH patient's health care continuum (preceding health care exposure and NH stay) and to investigate whether recent antibiotic exposure is associated with MDRO colonization and room environment contamination at NH study enrollment.

DESIGN, SETTING, AND PARTICIPANTS

This is a secondary analysis of a prospective cohort study (conducted from 2013-2016) that enrolled NH patients and followed them up for as long as 6 months. The study was conducted in 6 NHs in Michigan among NH patients who were enrolled within 14 days of admission. Clinical metadata abstraction, multi-anatomical site screening, and room environment surveillance for MDROs were conducted at each study visit. Data were analyzed between May 2019 and November 2021.

EXPOSURES

Antibiotic data were abstracted from NH electronic medical records by trained research staff and characterized by class, route, indication, location of therapy initiation, risk for Clostridioides difficile infection (C diffogenic agents), and 2019 World Health Organization Access, Watch, and Reserve (AWARE) antibiotic stewardship framework categories.

MAIN OUTCOMES AND MEASURES

The primary outcomes were MDRO colonization and MDRO room environment contamination at NH study enrollment, measured using standard microbiology methods. Multivariable logistic regression was used to identify whether antibiotic exposure within 60 days was associated with MDRO burden at NH study enrollment. Additionally, antibiotic exposure data were characterized using descriptive statistics.

RESULTS

A total of 642 patients were included (mean [SD] age, 74.7 [12.2] years; 369 [57.5%] women; 402 [62.6%] White; median [IQR] NH days to enrollment, 6.0 [3.0-7.0]). Of these, 422 (65.7%) received 1191 antibiotic exposures: 368 (57.3%) received 971 hospital-associated prescriptions, and 119 (18.5%) received 198 NH-associated prescriptions. Overall, 283 patients (44.1%) received at least 1 C diffogenic agent, and 322 (50.2%) received at least 1 high-risk WHO AWARE antibiotic (watch or reserve agent). More than half of NH patients (364 [56.7%]) and room environments (437 [68.1%]) had MDRO-positive results at enrollment. In multivariable analysis, recent antibiotic exposure was positively associated with baseline MDRO colonization (odds ratio [OR], 1.70; 95% CI, 1.22-2.38) and MDRO environmental contamination (OR, 1.67; 95% CI, 1.17-2.39). Exploratory stratification by C diffogenic agent exposure increased the effect size (MDRO colonization: OR, 1.99; 95% CI, 1.33-2.96; MDRO environmental contamination: OR, 1.86; 95% CI, 1.24-2.79). Likewise, exploratory stratification by exposure to high-risk WHO AWARE antibiotics increased the effect size (MDRO colonization: OR, 2.32; 95% CI, 1.61-3.36; MDRO environmental contamination: OR, 1.86; 95% CI, 1.26-2.75).

CONCLUSIONS AND RELEVANCE

The findings of this study suggest that high-risk, hospital-based antibiotics are a potentially high-value target to reduce MDROs in postacute care NHs. This study underscores the potential utility of integrated hospital and NH stewardship programming on regional MDRO epidemiology.

Redundant Anaerobic Antimicrobial Prescriptions in German Acute Care Hospitals: Data from a National Point Prevalence Survey

Despite limited indications, redundant anaerobic antimicrobial prescriptions (RAAPs) are frequent. The objective of this study was to assess the prevalence and characteristics of RAAPs in German acute care hospitals. In a retrospective data analysis, antimicrobial prescriptions from a point prevalence survey on antimicrobial use in German acute care hospitals in 2016 were analyzed and RAAPs were identified. RAAPs were defined as a patient simultaneously receiving any of the following combinations: Penicillin/beta-lactamase inhibitor (PenBLI) plus clindamycin; PenBLI plus metronidazole; PenBLI plus moxifloxacin; PenBLI plus carbapenem; carbapenem plus clindamycin; carbapenem plus metronidazole; carbapenem plus moxifloxacin; clindamycin plus metronidazole; clindamycin plus moxifloxacin; and metronidazole plus moxifloxacin. Data from 64,412 patients in 218 hospitals were included. Overall, 4486 patients (7%) received two or more antimicrobials. In total, 441 RAAP combinations were identified. PenBLI plus metronidazole was the most common anaerobic combination (N = 166, 38%). The majority of RAAPs were for the treatment of community-acquired (N = 258, 59%) infections. Lower respiratory tract infections (N = 77; 20%) and skin/soft tissue infections (N = 76; 20%) were the most frequently recorded types of infections. RAAPs are common in German hospitals. Reducing redundant antimicrobial coverage should be a key component of future antimicrobial stewardship activities.

Redundant combinations of antianaerobic antimicrobials: impact of pharmacist-based prospective audit and feedback and prescription characteristics

This study aimed to evaluate the impact of the intervention targeting the redundant combination of antianaerobic antimicrobials on its incidence and associated antimicrobial consumption. To reveal the characteristics of the combination and the change in the related workload over time was an additional aim of the study. The combinations of metronidazole or clindamycin with antianaerobic antimicrobials were classified into redundant or acceptable, according to the target indications. A pharmacist-based prospective audit and feedback targeting the redundant antianaerobic combination was conducted. Segmented regression analysis was performed to evaluate the impact of the intervention. As a quantitative index of the interventional activity, the change in the number of signed consultation notes was evaluated. After the initiation of the intervention, the median monthly cumulative incidence of the redundant combination decreased from 5.29 (Interquartile range [IQR] 4.94-5.70) to 3.33 (IQR 2.87-3.71) (p < 0.001) per 1000 admissions per month. The consumption of concurrently administered metronidazole and clindamycin decreased from 3.34 (IQR 2.97-4.10) to 1.74 (IQR 1.19-1.93) (p < 0.001) per 1000 patient-days per month. Segmented regression analysis revealed that the monthly cumulative incidence decreased by 28.5% after the initiation of the intervention (change in level - 1.640, p = 0.019) and the monthly consumption decreased by 33.9% (change in level - 1.409, p = 0.009). The number of consultation notes per 1000 admissions per month decreased over time (regression coefficient - 0.004, p < 0.001). The pharmacist-based intervention significantly reduced the incidence and associated antimicrobial consumption of the redundant antianaerobic combination. The overall related workload reduced steadily over time.

Reducing Redundant Anaerobic Therapy Through Spaced Education and Antimicrobial Stewardship Interventions

BACKGROUND

Decreasing the use of redundant anaerobic therapy is a key target for antimicrobial stewardship. Education techniques that optimize knowledge retention could be an important component of reducing these regimens.

METHODS

We implemented a quality improvement project that incorporated spaced education to reduce the use of redundant anaerobic therapy. The initial interventions (November through December 2015) included education in a hospital-wide newsletter and review of redundant anaerobic regimens by the antimicrobial stewardship program. A spaced education module was then developed with the gastroenterology (GI) service, which had a relatively high rate of redundant anaerobic therapy use. Ten questions with teaching points were delivered to GI physicians at spaced intervals over 2 to 4 weeks (February through March 2016). Knowledge scores were compared at initial and final question presentation using generalized estimating equations. Interrupted time-series analysis was used to compare the rates of redundant-metronidazole-days per 1000 patient-days among patients in the patients admitted to the GI service and those in the non-GI group before and after the intervention.

RESULTS

Of 66 GI physicians, 56 (85%) participated in the spaced education activity. After the intervention, their knowledge scores on all the questions improved, and their mean knowledge score increased from 57% to 86% (P < .001). Nearly all (91%) of the participants were very or generally satisfied with the activity. In the GI group, the rate of redundant-metronidazole-days decreased from 26.2 to 13.0 per 1000 patient-days (relative risk [RR], 0.45 [95% confidence interval (CI), 0.27-0.73]; P = .001). This rate in the non-GI group also decreased from 5.47 to 2.18 per 1000 patient-days (RR, 0.47 [95% CI, 0.36-0.60]; P < .001) after our interventions.

CONCLUSIONS

Spaced education is an effective approach for teaching antimicrobial stewardship topics. Focused provider education was associated with a sustained reduction in the use of redundant anaerobic therapy.

Changes in antimicrobial prescribing behavior after the introduction of the antimicrobial stewardship program: A pre- and post-intervention survey

The introduction of an antimicrobial stewardship (AMS) program is associated with a change in antimicrobial prescribing behavior. A proposed mechanism for this change is by impacting the prescribing etiquette described in qualitative studies. This study sought to detect a change in prescribing attitudes 12 months after the introduction of AMS and gauge utility of various AMS interventions. Surveys were distributed to doctors in two regional Australian hospitals on a convenience basis 6 months before, and 12 months after, the introduction of AMS. Agreement with 20 statements describing attitudes (cultural, behavioral and knowledge) towards antimicrobial prescribing was assessed on a 4-point Likert scale. Mean response scores were compared using the Wilcoxon Rank sum test. 155 responses were collected before the introduction of AMS, and 144 afterwards. After the introduction of AMS, an increase was observed in knowledge about available resources such as electronic decision support systems (EDSS) and therapeutic guidelines, with raised awareness about the support available through AMS rounds and the process to be followed when prescribing restricted antimicrobials. Additionally, doctors were less likely to rely on pharmacy to ascertain when an antimicrobial was restricted, depend on infectious diseases consultant advice and use past experience to guide antimicrobial prescribing. Responses to this survey indicate that positive changes to the antimicrobial prescribing etiquette may be achieved with the introduction of an AMS program. Use of EDSS and other resources such as evidence-based guidelines are perceived to be important to drive rational antimicrobial prescribing within AMS programs.

Interventions to improve antibiotic prescribing practices for hospital inpatients

BACKGROUND

Antibiotic resistance is a major public health problem. Infections caused by multidrug-resistant bacteria are associated with prolonged hospital stay and death compared with infections caused by susceptible bacteria. Appropriate antibiotic use in hospitals should ensure effective treatment of patients with infection and reduce unnecessary prescriptions. We updated this systematic review to evaluate the impact of interventions to improve antibiotic prescribing to hospital inpatients.

OBJECTIVES

To estimate the effectiveness and safety of interventions to improve antibiotic prescribing to hospital inpatients and to investigate the effect of two intervention functions: restriction and enablement.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library), MEDLINE, and Embase. We searched for additional studies using the bibliographies of included articles and personal files. The last search from which records were evaluated and any studies identified incorporated into the review was January 2015.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and non-randomised studies (NRS). We included three non-randomised study designs to measure behavioural and clinical outcomes and analyse variation in the effects: non- randomised trials (NRT), controlled before-after (CBA) studies and interrupted time series (ITS) studies. For this update we also included three additional NRS designs (case control, cohort, and qualitative studies) to identify unintended consequences. Interventions included any professional or structural interventions as defined by the Cochrane Effective Practice and Organisation of Care Group. We defined restriction as 'using rules to reduce the opportunity to engage in the target behaviour (or increase the target behaviour by reducing the opportunity to engage in competing behaviours)'. We defined enablement as 'increasing means/reducing barriers to increase capability or opportunity'. The main comparison was between intervention and no intervention.

DATA COLLECTION AND ANALYSIS

Two review authors extracted data and assessed study risk of bias. We performed meta-analysis and meta-regression of RCTs and meta-regression of ITS studies. We classified behaviour change functions for all interventions in the review, including those studies in the previously published versions. We analysed dichotomous data with a risk difference (RD). We assessed certainty of evidence with GRADE criteria.

MAIN RESULTS

This review includes 221 studies (58 RCTs, and 163 NRS). Most studies were from North America (96) or Europe (87). The remaining studies were from Asia (19), South America (8), Australia (8), and the East Asia (3). Although 62% of RCTs were at a high risk of bias, the results for the main review outcomes were similar when we restricted the analysis to studies at low risk of bias.More hospital inpatients were treated according to antibiotic prescribing policy with the intervention compared with no intervention based on 29 RCTs of predominantly enablement interventions (RD 15%, 95% confidence interval (CI) 14% to 16%; 23,394 participants; high-certainty evidence). This represents an increase from 43% to 58% .There were high levels of heterogeneity of effect size but the direction consistently favoured intervention.The duration of antibiotic treatment decreased by 1.95 days (95% CI 2.22 to 1.67; 14 RCTs; 3318 participants; high-certainty evidence) from 11.0 days. Information from non-randomised studies showed interventions to be associated with improvement in prescribing according to antibiotic policy in routine clinical practice, with 70% of interventions being hospital-wide compared with 31% for RCTs. The risk of death was similar between intervention and control groups (11% in both arms), indicating that antibiotic use can likely be reduced without adversely affecting mortality (RD 0%, 95% CI -1% to 0%; 28 RCTs; 15,827 participants; moderate-certainty evidence). Antibiotic stewardship interventions probably reduce length of stay by 1.12 days (95% CI 0.7 to 1.54 days; 15 RCTs; 3834 participants; moderate-certainty evidence). One RCT and six NRS raised concerns that restrictive interventions may lead to delay in treatment and negative professional culture because of breakdown in communication and trust between infection specialists and clinical teams (low-certainty evidence).Both enablement and restriction were independently associated with increased compliance with antibiotic policies, and enablement enhanced the effect of restrictive interventions (high-certainty evidence). Enabling interventions that included feedback were probably more effective than those that did not (moderate-certainty evidence).There was very low-certainty evidence about the effect of the interventions on reducing Clostridium difficile infections (median -48.6%, interquartile range -80.7% to -19.2%; 7 studies). This was also the case for resistant gram-negative bacteria (median -12.9%, interquartile range -35.3% to 25.2%; 11 studies) and resistant gram-positive bacteria (median -19.3%, interquartile range -50.1% to +23.1%; 9 studies). There was too much variance in microbial outcomes to reliably assess the effect of change in antibiotic use. Heterogeneity of intervention effect on prescribing outcomesWe analysed effect modifiers in 29 RCTs and 91 ITS studies. Enablement and restriction were independently associated with a larger effect size (high-certainty evidence). Feedback was included in 4 (17%) of 23 RCTs and 20 (47%) of 43 ITS studies of enabling interventions and was associated with greater intervention effect. Enablement was included in 13 (45%) of 29 ITS studies with restrictive interventions and enhanced intervention effect.

AUTHORS' CONCLUSIONS

We found high-certainty evidence that interventions are effective in increasing compliance with antibiotic policy and reducing duration of antibiotic treatment. Lower use of antibiotics probably does not increase mortality and likely reduces length of stay. Additional trials comparing antibiotic stewardship with no intervention are unlikely to change our conclusions. Enablement consistently increased the effect of interventions, including those with a restrictive component. Although feedback further increased intervention effect, it was used in only a minority of enabling interventions. Interventions were successful in safely reducing unnecessary antibiotic use in hospitals, despite the fact that the majority did not use the most effective behaviour change techniques. Consequently, effective dissemination of our findings could have considerable health service and policy impact. Future research should instead focus on targeting treatment and assessing other measures of patient safety, assess different stewardship interventions, and explore the barriers and facilitators to implementation. More research is required on unintended consequences of restrictive interventions.

Impact of an Antimicrobial Stewardship Program on Unnecessary Double Anaerobic Coverage Prescription

Background

Co-administration of two or more antimicrobials with anti-anaerobic activity is not recommended except in certain circumstances. We therefore conducted an intervention to reduce unnecessary double anaerobic coverage (DAC) prescription.

Materials and Methods

The intervention consisted of education using an institutional intranet and prospective audits and feedback provided through collaboration between a pharmacist and an infectious diseases physician in Seoul National University Bundang Hospital, a tertiary hospital in Seongnam, Republic of Korea, in 2013. The study period was 1 year which contained 6 months of pre-intervention period and 6 months of intervention period. To estimate the overall effect of the intervention, we compared the monthly number of patients receiving unnecessary DAC for more than 3 days and the proportion of patients receiving unnecessary DAC for more than 3 days among all patients receiving DAC.

Results

The average monthly number of patients receiving unnecessary DAC for more than 3 days after screening decreased by 73.9% in the intervention period from 26.8 to 7.0. Wilcoxon rank sum test revealed there was a significant statistical difference in the monthly number of patients receiving unnecessary DAC for more than 3 days (P = 0.005). The proportion of patients receiving unnecessary DAC for more than 3 days after screening among all patients identified as receiving necessary or unnecessary DAC also decreased by 67.8% in the intervention period from 42.3% to 13.6% (P < 0.001).

Conclusion

The multidisciplinary antimicrobial stewardship program with combined methods reduced unnecessary DAC prescription successfully.

The effect of obesity on clinical outcomes in presumed sepsis: a retrospective cohort study

Sepsis is a major cause of hospital admissions and mortality. Nevertheless, there are significant gaps in our knowledge of the epidemiology of sepsis in obese people, who now represent more than one-third of the population in the United States. The objective of this study was to measure the association between obesity and mortality from presumed sepsis. A retrospective cohort study was used of 1,779 adult inpatients with presumed sepsis at a Tertiary Care Academic Institution from March 1, 2007 to June 30, 2011. Cases of sepsis were identified using a standardized algorithm for sepsis antibiotic treatment. Exposure (i.e., obesity) was defined as a body mass index ≥30 kg/m(2). Multivariable logistic regression was used to assess the adjusted association between obesity and mortality. Patients with presumed sepsis were of a median age of 60.9 years (interquartile range 49.7-71) and 41.1 % were women. A total of 393 patients died, resulting in a 28-day in-hospital mortality of 22.1 %. In adjusted analysis, obesity was not significantly associated with increased mortality (odds ratio 1.11, 95 % CI 0.85-1.41, P = 0.47). There was also no difference in the in-hospital length of stay (P = 0.45) or maximum percent change in serum creatinine (P = 0.32) between obese and non-obese patients. Finally, there was no difference in the proportion of initial inadequate vancomycin levels (P = 0.1) after presumed sepsis. Obesity was not associated with increased mortality in patients with presumed sepsis. Further research is needed to determine how excess adiposity modulates inflammation from sepsis.

Interventions to improve antibiotic prescribing practices for hospital inpatients

BACKGROUND

The first publication of this review in Issue 3, 2005 included studies up to November 2003. This update adds studies to December 2006 and focuses on application of a new method for meta-analysis of interrupted time series studies and application of new Cochrane Effective Practice and Organisation of Care (EPOC) Risk of Bias criteria to all studies in the review, including those studies in the previously published version. The aim of the review is to evaluate the impact of interventions from the perspective of antibiotic stewardship. The two objectives of antibiotic stewardship are first to ensure effective treatment for patients with bacterial infection and second support professionals and patients to reduce unnecessary use and minimize collateral damage.

OBJECTIVES

To estimate the effectiveness of professional interventions that, alone or in combination, are effective in antibiotic stewardship for hospital inpatients, to evaluate the impact of these interventions on reducing the incidence of antimicrobial-resistant pathogens or Clostridium difficile infection and their impact on clinical outcome.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE from 1980 to December 2006 and the EPOC specialized register in July 2007 and February 2009 and bibliographies of retrieved articles. The main comparison is between interventions that had a restrictive element and those that were purely persuasive. Restrictive interventions were implemented through restriction of the freedom of prescribers to select some antibiotics. Persuasive interventions used one or more of the following methods for changing professional behaviour: dissemination of educational resources, reminders, audit and feedback, or educational outreach. Restrictive interventions could contain persuasive elements.

SELECTION CRITERIA

We included randomized clinical trials (RCTs), controlled clinical trials (CCT), controlled before-after (CBA) and interrupted time series studies (ITS). Interventions included any professional or structural interventions as defined by EPOC. The intervention had to include a component that aimed to improve antibiotic prescribing to hospital inpatients, either by increasing effective treatment or by reducing unnecessary treatment. The results had to include interpretable data about the effect of the intervention on antibiotic prescribing or microbial outcomes or relevant clinical outcomes.

DATA COLLECTION AND ANALYSIS

Two authors extracted data and assessed quality. We performed meta-regression of ITS studies to compare the results of persuasive and restrictive interventions. Persuasive interventions advised physicians about how to prescribe or gave them feedback about how they prescribed. Restrictive interventions put a limit on how they prescribed; for example, physicians had to have approval from an infection specialist in order to prescribe an antibiotic. We standardized the results of some ITS studies so that they are on the same scale (percent change in outcome), thereby facilitating comparisons of different interventions. To do this, we used the change in level and change in slope to estimate the effect size with increasing time after the intervention (one month, six months, one year, etc) as the percent change in level at each time point. We did not extrapolate beyond the end of data collection after the intervention. The meta-regression was performed using standard weighted linear regression with the standard errors of the coefficients adjusted where necessary.

MAIN RESULTS

For this update we included 89 studies that reported 95 interventions. Of the 89 studies, 56 were ITSs (of which 4 were controlled ITSs), 25 were RCT (of which 5 were cluster-RCTs), 5 were CBAs and 3 were CCTs (of which 1 was a cluster-CCT).Most (80/95, 84%) of the interventions targeted the antibiotic prescribed (choice of antibiotic, timing of first dose and route of administration). The remaining 15 interventions aimed to change exposure of patients to antibiotics by targeting the decision to treat or the duration of treatment. Reliable data about impact on antibiotic prescribing data were available for 76 interventions (44 persuasive, 24 restrictive and 8 structural). For the persuasive interventions, the median change in antibiotic prescribing was 42.3% for the ITSs, 31.6% for the controlled ITSs, 17.7% for the CBAs, 3.5% for the cluster-RCTs and 24.7% for the RCTs. The restrictive interventions had a median effect size of 34.7% for the ITSs, 17.1% for the CBAs and 40.5% for the RCTs. The structural interventions had a median effect of 13.3% for the RCTs and 23.6% for the cluster-RCTs. Data about impact on microbial outcomes were available for 21 interventions but only 6 of these also had reliable data about impact on antibiotic prescribing.Meta-analysis of 52 ITS studies was used to compare restrictive versus purely persuasive interventions. Restrictive interventions had significantly greater impact on prescribing outcomes at one month (32%, 95% confidence interval (CI) 2% to 61%, P = 0.03) and on microbial outcomes at 6 months (53%, 95% CI 31% to 75%, P = 0.001) but there were no significant differences at 12 or 24 months. Interventions intended to decrease excessive prescribing were associated with reduction in Clostridium difficile infections and colonization or infection with aminoglycoside- or cephalosporin-resistant gram-negative bacteria, methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus faecalis. Meta-analysis of clinical outcomes showed that four interventions intended to increase effective prescribing for pneumonia were associated with significant reduction in mortality (risk ratio 0.89, 95% CI 0.82 to 0.97), whereas nine interventions intended to decrease excessive prescribing were not associated with significant increase in mortality (risk ratio 0.92, 95% CI 0.81 to 1.06).

AUTHORS' CONCLUSIONS

The results show that interventions to reduce excessive antibiotic prescribing to hospital inpatients can reduce antimicrobial resistance or hospital-acquired infections, and interventions to increase effective prescribing can improve clinical outcome. This update provides more evidence about unintended clinical consequences of interventions and about the effect of interventions to reduce exposure of patients to antibiotics. The meta-analysis supports the use of restrictive interventions when the need is urgent, but suggests that persuasive and restrictive interventions are equally effective after six months.

Double trouble: how big a problem is redundant anaerobic antibiotic coverage in Veterans Affairs medical centres?

OBJECTIVES

To assess the prevalence of, and the variation in, avoidable use of metronidazole in the Veterans Affairs (VA) healthcare system

METHODS

Barcode Medication Administration (BCMA) data were retrospectively assessed for all patients hospitalized between January 2006 and December 2010 in acute-care wards of all VA medical centres (VAMCs) with complete BCMA data and at least 10 acute-care non-intensive care unit (ICU) beds. Potentially avoidable metronidazole days of therapy (DOT) were defined as the administration of metronidazole with another anti-anaerobic antibiotic on the same day for at least two consecutive days during the same hospitalization. Metronidazole was not considered redundant in combination with another anti-anaerobic agent within 28 days after a positive test for Clostridium difficile and during hospitalizations associated with discharge diagnosis codes for cholecystitis or cholangitis.

RESULTS

A total of 128 VAMCs satisfied the inclusion criteria. Over the study period there were a total of 782,821 DOT of metronidazole (57.4 DOT per 1000 patient-days), of which 183,267 (23.4%) fulfilled the criteria for avoidable metronidazole DOT. The percentage of avoidable metronidazole DOT remained stable over the study period (22.8% in 2006 and 22.9% in 2010) despite a decrease in overall metronidazole use. There was wide variation in the percentage of avoidable metronidazole DOT among facilities (2010: median 20.3%, IQR 15.3%-29.4%). Piperacillin/tazobactam was the most commonly administered drug on avoidable metronidazole DOT (56.8%).

CONCLUSIONS

Potentially avoidable use of metronidazole affected about a quarter of all days when metronidazole was given. The combination of metronidazole with piperacillin/tazobactam was particularly common and represents a possible target for antibiotic stewardship interventions.