Impact of a fluoroquinolone restriction policy in an elderly population

Rapid Decrease in Fluoroquinolones Consumption following Implementation of a Simple Antimicrobial Stewardship Bundled Intervention in a University Hospital during the COVID-19 Pandemic

Fluoroquinolones (FQs) represent an class of antibiotics of medical importance, but their use has been restricted due to their ecologic impact and associated side effects. The reduction of FQs use is an important goal of antimicrobial stewardship programs (ASP). This work describes an ASP focused on overall antibiotics and FQs consumption reduction. From January 2021, an ASP was implemented in a 700-bed teaching hospital. The ASP was based on: (i) antibiotics consumption monitoring system (DDD/100 bed days); (ii) mandatory antibiotic prescription-motivation (using a dedicated informatic format) with the goal of >75% of motivated prescriptions; and (iii) data feedback and training on FQs use indications. We evaluated the impact of the intervention on overall systemic antibiotics and FQs consumption according to the objectives posed by Italian PNCAR (National Action Plan on Antimicrobial Resistance). A decrease of 6.6% in antibiotic use was observed (2019 vs. 2021). Notably, the FQs consumption fell by 48.3% from 7.1 DDD/100 bd in 2019 to 3.7 DDD/100 bd in 2021 (p < 0.001). After six months of mandatory antibiotic prescription-indication, all units achieved the target set. The study suggests that a simple, bundled ASP intervention can be rapidly effective obtaining the objectives of PNCAR on the reduction of overall antibiotics and FQs consumption.

A Non-Restrictive Approach to Fluoroquinolone Stewardship at Two Community Hospitals

Background

Fluoroquinolones are one of the most prescribed antimicrobials in the United States and have been increasingly used in inpatient and outpatient settings to treat various infectious diseases syndromes. Due to the unwanted collateral effects on antibiotic resistance, poor susceptibility rates among Gram-negative pathogens, and adverse effects, fluoroquinolones are often targeted by hospital antimicrobial stewardship programs to prevent overutilization. This study describes the association of nonrestrictive antimicrobial stewardship interventions at 2 nonacademic community hospitals on levofloxacin utilization, prescribing patterns on alternative antibiotics, and Pseudomonas aeruginosa nonsusceptibility rates to levofloxacin.

Methods

Nonrestrictive antimicrobial stewardship interventions included monitoring and reporting of fluoroquinolone susceptibility trends to physician groups, performing medication use evaluations of levofloxacin accompanied with prescriber detailing, daily prospective audit and feedback, implementation of beta-lactam-based institutional guidelines for empiric therapy in various infectious disease syndromes, review and adjustment of electronic medical record order sets containing fluoroquinolones, and intensive prescriber education. No preauthorization of levofloxacin was used during this study period. Antibiotic utilization data were collected for the time periods of August 2015 through January 2021. Correlation between levofloxacin and other broad-spectrum antibiotc use was investigated as well as the impact on Pseudomonas aeruginosa levofloxacin nonsusceptibility rates.

Results

Both hospitals showed an overall downward trend in the prescribing of levofloxacin during the time period of August 2015 to January 2021. There was a significant negative correlation between monthly ceftriaxone and levofloxacin days of therapy for both hospitals (P < .0001). There was a positive correlation between levofloxacin days of therapy and P aeruginosa nonsusceptibility (P < .02 at both hospitals).

Conclusions

Our results demonstrate that a nonrestrictive approach to fluoroquinolone stewardship interventions had a significant impact on reducing levofloxacin utilization, increasing ceftriaxone utilization, and improving P aeruginosa levofloxacin susceptibility.

Development and Validation of a Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) Assay for the Determination of Total and Unbound Ciprofloxacin Concentrations in Human Plasma

BACKGROUND

Although unbound ciprofloxacin is responsible for antibacterial effects, assays measuring the unbound drug plasma concentrations are scarce. This study aimed to develop and validate a rapid, reproducible, and sensitive liquid chromatography-tandem mass spectrometry assay for the determination of total and unbound ciprofloxacin plasma concentrations.

METHODS

The determination of total ciprofloxacin concentrations required a 10 μL sample, while for unbound ciprofloxacin concentrations, it was 100 μL. Unbound ciprofloxacin was separated from protein-bound ciprofloxacin through ultrafiltration. A deuterated internal standard was used, and the sample preparation involved protein precipitation. The method was fully validated over a concentration range of 0.02-5.0 mg/L, according to the US Food and Drug Administration guidelines. In addition, its clinical application was demonstrated.

RESULTS

The total run time was 1.5 minutes. For total ciprofloxacin plasma concentrations, the mean accuracy ranged from 94.5% to 105.0% across the validated range, the intraday imprecision was ≤7.6%, and the interday imprecision was ≤9.8%. For unbound ciprofloxacin plasma concentrations, the mean accuracy ranged from 92.8% to 102.1% across the validated range, the intraday imprecision was ≤7.0%, and the interday imprecision was ≤9.6%. Ciprofloxacin in plasma and ultrafiltrate remained stable for at least 96 hours at room temperature, at least 4 years at -80°C, and at least 3 freeze/thaw cycles (-80°C), with a minimum interval of 24 hours.

CONCLUSIONS

The presented method is precise and accurate. It has been implemented in clinical care and research projects at a university hospital, permitting rapid determination of total and unbound ciprofloxacin.

Behavioral Nudges to Improve Audit and Feedback Report Opening among Antibiotic Prescribers: A Randomized Controlled Trial

Background

Peer comparison audit and feedback has demonstrated effectiveness in improving antibiotic prescribing practices, but only a minority of prescribers view their reports. We rigorously tested three behavioral nudging techniques delivered by email to improve report opening.

Methods

We conducted a pragmatic randomized controlled trial among Ontario long-term care (LTC) prescribers enrolled in an ongoing peer comparison audit and feedback program which includes data on their antibiotic prescribing patterns. Physicians were randomized to 1 of 8 possible sequences of intervention/control allocation to 3 different behavioral email nudges: a social peer comparison nudge (January 2020), a maintenance of professional certification incentive nudge (October 2020), and a prior participation nudge (January 2021). The primary outcome was feedback report opening; the primary analysis pooled the effects of all 3 nudging interventions.

Results

The trial included 421 physicians caring for more than 28,000 residents at 450 facilities. In the pooled analysis, physicians opened only 29.6% of intervention and 23.9% of control reports (odds ratio (OR) 1.51 (95%CI 1.10-2.07, p=0.011); this difference remained significant after accounting for physician characteristics and clustering (adjusted OR (aOR) 1.74 (95%CI 1.24-2.45, p=0.0014). Of individual nudging techniques, the prior participation nudge was associated with a significant increase in report opening (OR 1.62, 95%CI 1.06-2.47, p=0.026; aOR 2.16, 95%CI 1.33-3.50, p=0.0018). In the pooled analysis, nudges were also associated with accessing more report pages (aOR 1.28, 95%CI 1.14-1.43, p&lt;0.001).

Conclusions

Enhanced nudging strategies modestly improved report opening, but more work is needed to optimize physician engagement with audit and feedback.

Ciprofloxacin accelerates aortic enlargement and promotes dissection and rupture in Marfan mice

OBJECTIVE

Aortic aneurysm and dissection are major life-threatening complications of Marfan syndrome. Avoiding factors that promote aortic damage is critical in managing the care of these patients. Findings from clinical and animal studies raise concerns regarding fluoroquinolone use in patients at risk for aortic aneurysm and dissection. Therefore, we examined the effects of ciprofloxacin on aortic aneurysm and dissection development in Marfan mice.

METHODS

Eight-week-old Marfan mice (Fbn1C1041G/+) were given ciprofloxacin (100 mg/kg/d; n = 51) or vehicle (n = 59) for 4 weeks. Mice were monitored for 16 weeks. Aortic diameters were measured by using ultrasonography, and aortic structure was examined by using histopathologic and immunostaining analyses.

RESULTS

Vehicle-treated Fbn1C1041G/+ mice showed progressive aortic enlargement, with aortic rupture occurring in 5% of these mice. Compared with vehicle-treated Fbn1C1041G/+ mice, ciprofloxacin-treated Fbn1C1041G/+ mice showed accelerated aortic enlargement (P = .01) and increased incidences of aortic dissection (25% vs 47%, P = .03) and rupture (5% vs 25%, P = .005). Furthermore, ciprofloxacin-treated Fbn1C1041G/+ mice had higher levels of elastic fiber fragmentation, matrix metalloproteinase expression, and apoptosis than did vehicle-treated Fbn1C1041G/+ mice.

CONCLUSIONS

Ciprofloxacin accelerates aortic root enlargement and increases the incidence of aortic dissection and rupture in Marfan mice, partially by suppressing lysyl oxidase expression and further compromising the inherited defect in aortic elastic fibers. Our findings substantiate that ciprofloxacin should be avoided in patients with Marfan syndrome.

Population-Wide Peer Comparison Audit and Feedback to Reduce Antibiotic Initiation and Duration in Long-Term Care Facilities with Embedded Randomized Controlled Trial

BACKGROUND

Antibiotic overprescribing in long-term care settings is driven by prescriber preferences and is associated with preventable harms for residents. We aimed to determine whether peer comparison audit and feedback reporting for physicians reduces antibiotic overprescribing among residents.

METHODS

We employed a province wide, difference-in-differences study of antibiotic prescribing audit and feedback, with an embedded pragmatic randomized controlled trial (RCT) across all long-term care facilities in Ontario, Canada, in 2019. The study year included 1238 physicians caring for 96 185 residents. In total, 895 (72%) physicians received no feedback; 343 (28%) were enrolled to receive audit and feedback and randomized 1:1 to static or dynamic reports. The primary outcomes were proportion of residents initiated on an antibiotic and proportion of antibiotics prolonged beyond 7 days per quarter.

RESULTS

Among all residents, between the first quarter of 2018 and last quarter of 2019, there were temporal declines in antibiotic initiation (28.4% to 21.3%) and prolonged duration (34.4% to 29.0%). Difference-in-differences analysis confirmed that feedback was associated with a greater decline in prolonged antibiotics (adjusted difference -2.65%, 95% confidence interval [CI]: -4.93 to -.28%, P = .026), but there was no significant difference in antibiotic initiation. The reduction in antibiotic durations was associated with 335 912 fewer days of treatment. The embedded RCT detected no differences in outcomes between the dynamic and static reports.

CONCLUSIONS

Peer comparison audit and feedback is a pragmatic intervention that can generate small relative reductions in the use of antibiotics for prolonged durations that translate to large reductions in antibiotic days of treatment across populations. Clinical Trials Registration. NCT03807466.

Regional variation in the potentially inappropriate first-line use of fluoroquinolones in Canada as a key to antibiotic stewardship? A drug utilization review study

Background

Serious adverse effects of fluoroquinolone antibiotics have been described for more than decade. Recently, several drug regulatory agencies have advised restricting their use in milder infections for which other treatments are available, given the potential for disabling and possibly persistent side effects. We aimed to describe variations in fluoroquinolone use for initial treatment of urinary tract infection (UTI), acute bacterial sinusitis (ABS), and acute exacerbation of chronic obstructive pulmonary disease (AECOPD) in the outpatient setting across Canada.

Methods

Using administrative health data from six provinces, we identified ambulatory visits with a diagnosis of uncomplicated UTI, uncomplicated AECOPD or ABS. Antibiotic exposure was determined by the first antibiotic dispensed within 5 days of the visit.

Results

We identified 4,303,144 uncomplicated UTI events among 2,170,027 women; the proportion of events treated with fluoroquinolones, mostly ciprofloxacin, varied across provinces, ranging from 18.6% (Saskatchewan) to 51.6% (Alberta). Among 3,467,678 ABS events (2,087,934 patients), between 2.2% (Nova Scotia) and 11.2% (Ontario) were dispensed a fluoroquinolone. For 1,319,128 AECOPD events among 598,347 patients, fluoroquinolones, mostly levofloxacin and moxifloxacin, ranged from 5.8% (Nova Scotia) to 35.6% (Ontario). The proportion of uncomplicated UTI and ABS events treated with fluoroquinolones declined over time, whereas it remained relatively stable for AECOPD.

Conclusions

Fluoroquinolones were commonly used as first-line therapies for uncomplicated UTI and AECOPD. However, their use varied widely across provinces. Drug insurance formulary criteria and enforcement may be a key to facilitating better antibiotic stewardship and limiting potentially inappropriate first-line use of fluoroquinolones.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06467-z.

Study reporting quality among interventions to reduce antibiotic use is a barrier to evidence-informed policymaking on antimicrobial resistance: systematic review

Background

Countries are currently seeking evidence-informed policy options to address antimicrobial resistance (AMR). While rigorous evaluations of AMR interventions are the ideal, they are far from the current reality. Additionally, poor reporting and documentation of AMR interventions impede efforts to use evidence to inform future evaluations and policy interventions.

Objectives

To critically evaluate reporting quality gaps in AMR intervention research.

Methods

To evaluate the reporting quality of studies, we conducted a descriptive synthesis and comparative analysis of studies that were included in a recent systematic review of government policy interventions aiming to reduce human antimicrobial use. Reporting quality was assessed using the SQUIRE 2.0 checklist of 18 items for reporting system-level interventions to improve healthcare. Two reviewers independently applied the checklist to 66 studies identified in the systematic review.

Results

None of the studies included complete information on all 18 SQUIRE items (median score = 10, IQR = 8–11). Reporting quality varied across SQUIRE items, with 3% to 100% of studies reporting the recommended information for each SQUIRE item. Only 20% of studies reported the elements of the intervention in sufficient detail for replication and only 24% reported the mechanism through which the intervention was expected to work.

Conclusions

Gaps in the reporting of impact evaluations pose challenges for interpreting and replicating study results. Failure to improve reporting practice of policy evaluations is likely to impede efforts to tackle the growing health, social and economic threats posed by AMR.

Metronidazole-associated Neurologic Events: A Nested Case-control Study

BACKGROUND

Case reports have described instances of peripheral and central nervous system toxicity during treatment with metronidazole; however, no large-scale studies have examined this association.

METHODS

We conducted a population-based nested case-control study of adults aged 66 years or older living in Ontario, Canada, between 1 April 2003 and 31 March 2017. Cases were individuals who attended hospital for any of cerebellar dysfunction, encephalopathy, or peripheral neuropathy within 100 days of a prescription for either metronidazole or clindamycin. We matched each case patient with up to 10 event-free control subjects who also received metronidazole or clindamycin. We used conditional logistic regression to test the association between metronidazole exposure and neurologic events, with clindamycin as the reference exposure.

RESULTS

We identified 1212 cases with recent use of either metronidazole or clindamycin and 12 098 controls. Neurologic adverse events were associated with an increased odds of metronidazole exposure compared to clindamycin (odds ratio [OR], 1.72 [95% confidence interval {CI}, 1.53-1.94]), which persisted after accounting for patient demographics, comorbidities, and other medication exposures (adjusted odds ratio [aOR], 1.43 [95% CI, 1.26-1.63]). We found a consistent association limited to either central (aOR, 1.46 [95% CI, 1.27-1.68]) or peripheral (aOR, 1.34 [95% CI, 1.02-1.76]) nervous system events. Among metronidazole recipients, the overall incidence of neurologic events at 100 days was approximately 0.25%.

CONCLUSIONS

Metronidazole is associated with an increased risk of adverse peripheral and central nervous system events relative to clindamycin. Clinicians and patients should be aware of these rare but potentially serious adverse events.

Use of interrupted time series methods in the evaluation of health system quality improvement interventions: a methodological systematic review

BACKGROUND

When randomisation is not possible, interrupted time series (ITS) design has increasingly been advocated as a more robust design to evaluating health system quality improvement (QI) interventions given its ability to control for common biases in healthcare QI. However, there is a potential risk of producing misleading results when this rather robust design is not used appropriately. We performed a methodological systematic review of the literature to investigate the extent to which the use of ITS has followed best practice standards and recommendations in the evaluation of QI interventions.

METHODS

We searched multiple databases from inception to June 2018 to identify QI intervention studies that were evaluated using ITS. There was no restriction on date, language and participants. Data were synthesised narratively using appropriate descriptive statistics. The risk of bias for ITS studies was assessed using the Cochrane Effective Practice and Organisation of Care standard criteria. The systematic review protocol was registered in PROSPERO (registration number: CRD42018094427).

RESULTS

Of 4061 potential studies and 2028 unique records screened for inclusion, 120 eligible studies assessed eight QI strategies and were from 25 countries. Most studies were published since 2010 (86.7%), reported data using monthly interval (71.4%), used ITS without a control (81%) and modelled data using segmented regression (62.5%). Autocorrelation was considered in 55% of studies, seasonality in 20.8% and non-stationarity in 8.3%. Only 49.2% of studies specified the ITS impact model. The risk of bias was high or very high in 72.5% of included studies and did not change significantly over time.

CONCLUSIONS

The use of ITS in the evaluation of health system QI interventions has increased considerably over the past decade. However, variations in methodological considerations and reporting of ITS in QI remain a concern, warranting a need to develop and reinforce formal reporting guidelines to improve its application in the evaluation of health system QI interventions.

Fluoroquinolones and Aortic Diseases: Is There a Connection

Fluoroquinolones (FQs) are one of the most commonly prescribed classes of antibiotics. Their high tissue distribution and broad-spectrum antibacterial coverage make their use very attractive in numerous infectious diseases. Although generally well tolerated, FQs have been associated with different adverse effects including dysglycemia and arrhythmias. FQs have been also associated with a series of adverse effects related to collagen degradation, such as Achilles tendon rupture and retinal detachment. Recently, an association between consumption of FQs and increased risk of aortic aneurysm and dissection has been proposed. This article reviews the pathogenesis of thoracic aortic diseases, the molecular mechanism of FQ-associated collagen toxicity, and the possible contribution of FQs to aortic diseases.

Government policy interventions to reduce human antimicrobial use: A systematic review and evidence map

BACKGROUND

Growing political attention to antimicrobial resistance (AMR) offers a rare opportunity for achieving meaningful action. Many governments have developed national AMR action plans, but most have not yet implemented policy interventions to reduce antimicrobial overuse. A systematic evidence map can support governments in making evidence-informed decisions about implementing programs to reduce AMR, by identifying, describing, and assessing the full range of evaluated government policy options to reduce antimicrobial use in humans.

METHODS AND FINDINGS

Seven databases were searched from inception to January 28, 2019, (MEDLINE, CINAHL, EMBASE, PAIS Index, Cochrane Central Register of Controlled Trials, Web of Science, and PubMed). We identified studies that (1) clearly described a government policy intervention aimed at reducing human antimicrobial use, and (2) applied a quantitative design to measure the impact. We found 69 unique evaluations of government policy interventions carried out across 4 of the 6 WHO regions. These evaluations included randomized controlled trials (n = 4), non-randomized controlled trials (n = 3), controlled before-and-after designs (n = 7), interrupted time series designs (n = 25), uncontrolled before-and-after designs (n = 18), descriptive designs (n = 10), and cohort designs (n = 2). From these we identified 17 unique policy options for governments to reduce the human use of antimicrobials. Many studies evaluated public awareness campaigns (n = 17) and antimicrobial guidelines (n = 13); however, others offered different policy options such as professional regulation, restricted reimbursement, pay for performance, and prescription requirements. Identifying these policies can inform the development of future policies and evaluations in different contexts and health systems. Limitations of our study include the possible omission of unpublished initiatives, and that policies not evaluated with respect to antimicrobial use have not been captured in this review.

CONCLUSIONS

To our knowledge this is the first study to provide policy makers with synthesized evidence on specific government policy interventions addressing AMR. In the future, governments should ensure that AMR policy interventions are evaluated using rigorous study designs and that study results are published.

PROTOCOL REGISTRATION

PROSPERO CRD42017067514.

Patients at Risk for Aortic Rupture Often Exposed to Fluoroquinolones during Hospitalization

Several studies have indicated that fluoroquinolone use may be associated with an increased risk of aortic aneurysm or dissection (AAD). Because patients with AAD or Marfan syndrome are at increased risk for aortic rupture, we performed a retrospective cohort study to determine the prevalence of systemic fluoroquinolone exposure and predictors of fluoroquinolone use in these patients. Data were obtained from the advisory board billing and administrative database, which contained information on 22 million adult hospitalizations in the United States for the study period (2009 to 2015). International Classification of Diseases (9/10) and Current Procedural Terminology codes were used to identify patients who had AAD or Marfan syndrome or underwent aortic repair. We identified 136,789 admissions for AAD, which involved 99,818 unique patients, 20% of whom received fluoroquinolone during a hospital admission. Of the 7,045 patients with dissection, 18% were exposed to fluoroquinolone. Of the 27,876 AAD patients who underwent aortic repair, 19% received fluoroquinolone during a hospitalization before the repair. In the AAD patients, having a diagnosis of pneumonia or urinary tract infection increased the likelihood of receiving fluoroquinolone during admission by 46% and 40%, respectively (P < 0.001). Additionally, we identified 2,871 admissions for Marfan syndrome, which involved 1,872 patients, 14% of whom received fluoroquinolone during an admission. In these patients, pneumonia and urinary tract infections also increased the risk of fluoroquinolone exposure. If the deleterious effects of fluoroquinolone on aortic integrity are substantiated, reducing fluoroquinolone use in hospitalized patients with aortic disorders will become an urgent safety issue for antibiotic stewardship programs.

The Association of Resident Communication Abilities and Antibiotic Use in Long-Term Care

OBJECTIVES

To determine whether decreased communication ability among long-term care residents is associated with increased antibiotic exposure.

DESIGN

Retrospective cohort study.

SETTING

All long-term care homes in Ontario, Canada.

PARTICIPANTS

All adults aged 66 years or older residing in long-term care and undergoing a full assessment between January 1 and December 31, 2016 (N = 87,947).

MEASUREMENTS

Data were obtained from linkable, population-wide administrative data sets. Residents were identified, and characteristics were abstracted from the Resident Assessment Instrument Minimum Dataset version 2.0. The primary predictors of interest were residents' ability to make themselves understood and ability to understand others. The primary outcome was antibiotic days of treatment per 1000 resident days in the 90 days following assessment (obtained from the Ontario Drug Benefits Database).

RESULTS

Those who were sometimes/rarely/never able to make themselves understood received 50.7 antibiotic days per 1000 person-days of follow-up, compared to 62.1 received by those who were able to make themselves understood. Those who were sometimes/rarely/never able to understand others received 50.0 antibiotic days per 1000 person-days of follow-up, compared to 61.4 by those who were able to understand others. Multivariable Poisson regression, accounting for resident characteristics, confirmed that compared to those with highest levels of communication ability, those who could sometimes/rarely/never make themselves understood had significantly fewer days on antibiotics (rate ratio [RR] = 0.76; confidence interval [95% CI] = 0.73-0.79) as did those who could sometimes/rarely/never understand others (RR = 0.76; 95% CI = 0.74-0.79).

CONCLUSION

Poor resident communication ability is not a driver of antibiotic overuse in long-term care. In fact, lower ability to understand others and/or be understood by others is associated with less antibiotic exposure. Further work is needed to optimize antibiotic use in long-term care residents across the entire spectrum of communication skills.

Effect of Ciprofloxacin on Susceptibility to Aortic Dissection and Rupture in Mice

Importance

Fluoroquinolones are among the most commonly prescribed antibiotics. Recent clinical studies indicated an association between fluoroquinolone use and increased risk of aortic aneurysm and dissection (AAD). This alarming association has raised concern, especially in patients with AAD with risk of rupture and in individuals at risk for developing AAD.

Objective

To examine the effect of ciprofloxacin on AAD development in mice.

Design, Setting, and Participants

In a mouse model of moderate, sporadic AAD, 4-week-old male and female C57BL/6J mice were challenged with a high-fat diet and low-dose angiotensin infusion (1000 ng/min/kg). Control unchallenged mice were fed a normal diet and infused with saline. After randomization, challenged and unchallenged mice received ciprofloxacin (100 mg/kg/d) or vehicle through daily gavage during angiotensin or saline infusion. Aortic aneurysm and dissection development and aortic destruction were compared between mice. The direct effects of ciprofloxacin on aortic smooth muscle cells were examined in cultured cells.

Results

No notable aortic destruction was observed in unchallenged mice that received ciprofloxacin alone. Aortic challenge induced moderate aortic destruction with development of AAD in 17 of 38 mice (45%) and severe AAD in 9 (24%) but no rupture or death. However, challenged mice that received ciprofloxacin had severe aortic destruction and a significantly increased incidence of AAD (38 of 48 [79%]; P = .001; χ2 = 10.9), severe AAD (32 of 48 [67%]; P < .001; χ2 = 15.7), and rupture and premature death (7 of 48 [15%]; P = .01; χ2 = 6.0). The increased AAD incidence was observed in different aortic segments and was similar between male and female mice. Compared with aortic tissues from challenged control mice, those from challenged mice that received ciprofloxacin showed decreased expression of lysyl oxidase, an enzyme that is critical in the assembly and stabilization of elastic fibers and collagen. These aortas also showed increased matrix metalloproteinase levels and activity, elastic fiber fragmentation, and aortic cell injury. In cultured smooth muscle cells, ciprofloxacin treatment significantly reduced lysyl oxidase expression and activity, increased matrix metalloproteinase expression and activity, suppressed cell proliferation, and induced cell death. Furthermore, ciprofloxacin-a DNA topoisomerase inhibitor-caused nuclear and mitochondrial DNA damage and the release of DNA into the cytosol, subsequently inducing mitochondrial dysfunction, reactive oxygen species production, and activation of the cytosolic DNA sensor STING, which we further showed was involved in the suppression of lysyl oxidase expression and induction of matrix metalloproteinase expression.

Conclusions and Relevance

Ciprofloxacin increases susceptibility to aortic dissection and rupture in a mouse model of moderate, sporadic AAD. Ciprofloxacin should be used with caution in patients with aortic dilatation, as well as in those at high risk for AAD.

Influences on the start, selection and duration of treatment with antibiotics in long-term care facilities

BACKGROUND

Understanding the extent to which current antibiotic prescribing behaviour is influenced by clinicians' historical patterns of practice will help target interventions to optimize antibiotic use in long-term care. Our objective was to evaluate whether clinicians' historical prescribing behaviours influence the start, prolongation and class selection for treatment with antibiotics in residents of long-term care facilities.

METHODS

We conducted a retrospective cohort study of all physicians who prescribed to residents in long-term care facilities in Ontario between Jan. 1 and Dec. 31, 2014. We examined variability in antibiotic prescribing among physicians for 3 measures: start of treatment with antibiotics, use of prolonged durations exceeding 7 days and selection of fluoroquinolones. Funnel plots with control limits were used to determine the extent of variation and characterize physicians as extreme low, low, average, high and extreme high prescribers for each tendency. Multivariable logistic regression was used to assess whether a clinician's prescribing tendency in the previous year predicted current prescribing patterns, after accounting for residents' demographics, comorbidity, functional status and indwelling devices.

RESULTS

Among 1695 long-term care physicians, who prescribed for 93 132 residents, there was wide variability in the start of antibiotic treatment (median 45% of patients, interquartile range [IQR] 32%-55%), use of prolonged treatment durations (median 30% of antibiotic prescriptions, IQR 19%-46%) and selection of fluoroquinolones (median 27% of antibiotic prescriptions, IQR 18%-37%). Prescribing tendencies for antibiotics by physicians in 2014 correlated strongly with tendencies in the previous year. After controlling for individual resident characteristics, prior prescribing tendency was a significant predictor of current practice.

INTERPRETATION

Physicians prescribing antibiotics exhibited individual, measurable and historical tendencies toward start of antibiotic treatment, use of prolonged treatment duration and class selection. Prescriber audit and feedback may be a promising tool to optimize antibiotic use in long-term care facilities.

Effect of a Health Care System Respiratory Fluoroquinolone Restriction Program To Alter Utilization and Impact Rates of Clostridium difficile Infection

Fluoroquinolones are one of the most commonly prescribed antibiotic classes in the United States despite their association with adverse consequences, including Clostridium difficile infection (CDI). We sought to evaluate the impact of a health care system antimicrobial stewardship-initiated respiratory fluoroquinolone restriction program on utilization, appropriateness of quinolone-based therapy based on institutional guidelines, and CDI rates. After implementation, respiratory fluoroquinolone utilization decreased from a monthly mean and standard deviation (SD) of 41.0 (SD = 4.4) days of therapy (DOT) per 1,000 patient days (PD) preintervention to 21.5 (SD = 6.4) DOT/1,000 PD and 4.8 (SD = 3.6) DOT/1,000 PD posteducation and postrestriction, respectively. Using segmented regression analysis, both education (14.5 DOT/1,000 PD per month decrease; P = 0.023) and restriction (24.5 DOT/1,000 PD per month decrease; P < 0.0001) were associated with decreased utilization. In addition, the CDI rates decreased significantly (P = 0.044) from preintervention using education (3.43 cases/10,000 PD) and restriction (2.2 cases/10,000 PD). Mean monthly CDI cases/10,000 PD decreased from 4.0 (SD = 2.1) preintervention to 2.2 (SD = 1.35) postrestriction. A significant increase in appropriate respiratory fluoroquinolone use occurred postrestriction versus preintervention in patients administered at least one dose (74/130 [57%] versus 74/232 [32%]; P < 0.001), as well as in those receiving two or more doses (47/65 [72%] versus 67/191 [35%]; P < 0.001). A significant reduction in the annual acquisition cost of moxifloxacin, the formulary respiratory fluoroquinolone, was observed postrestriction compared to preintervention within the health care system ($123,882 versus $12,273; P = 0.002). Implementation of a stewardship-initiated respiratory fluoroquinolone restriction program can increase appropriate use while reducing overall utilization, acquisition cost, and CDI rates within a health care system.

Variations in costs and use of provincially-funded testosterone replacement therapy across Canada: a population-based study

INTRODUCTION

Provincial drug-program policies for the reimbursement of testosterone replacement therapy (TRT) vary across Canada, which may result in marked regional variability in use.

METHODS

We conducted a population-based cross-sectional analysis of provincially funded TRT spending and utilization in eight provinces across Canada in 2012. We reported the annual cost per user, total cost, and rate of use of TRT overall and by formulation.

RESULTS

We identified 23,544 provincially-funded recipients of TRT in 2012 in the eight provinces studied. Average annual cost per person varied by 3-fold, ranging from $173 (Prince Edward Island) to $485 (Ontario). Ontario also had the highest rate of use (1,105 users per 100,000 eligible) and the most liberal listing. Provinces with more restricted access (Alberta, British Columbia, and PEI) had lower annual costs per user ($293, $206, $173, respectively).

CONCLUSIONS

Differing reimbursement policies for TRT products across Canada are likely contributing to variation in the rate of use and cost per recipient.

Fluoroquinolones and collagen associated severe adverse events: a longitudinal cohort study

OBJECTIVES

Fluoroquinolone-associated tendon ruptures are a recognised complication, but other severe collagen-associated adverse events may also be possible. Our objectives were to confirm the association of fluoroquinolones and tendon rupture, to clarify the potential association of fluoroquinolones and retinal detachment, and to test for a potentially lethal association between fluoroquinolones and aortic aneurysms.

SETTING

Population-based longitudinal cohort study in Ontario, Canada.

PARTICIPANTS

Older adults turning 65 years between April 1 1997 and March 31 2012 were followed until primary outcome, death, or end of follow-up (March 31 2014). Fluoroquinolone prescriptions were measured as a time-varying covariate, with patients considered at risk during and for 30 days following a treatment course.

PRIMARY OUTCOME MEASURES

Severe collagen-associated adverse events defined as tendon ruptures, retinal detachments and aortic aneurysms diagnosed in hospital and emergency departments.

RESULTS

Among the 1,744,360 eligible patients, 657,950 (38%) received at least one fluoroquinolone during follow-up, amounting to 22,380,515 days of treatment. The patients experienced 37,338 (2.1%) tendon ruptures, 3246 (0.2%) retinal detachments, and 18,391 (1.1%) aortic aneurysms. Severe collagen-associated adverse events were more common during fluoroquinolone treatment than control periods, including tendon ruptures (0.82 vs 0.26/100-person years, p<0.001), retinal detachments (0.03 vs 0.02/100-person-years, p=0.003) and aortic aneurysms (0.35 vs 0.13/100-person-years, p<0.001). Current fluoroquinolones were associated with an increased hazard of tendon rupture (HR 3.13, 95% CI 2.98 to 3.28; adjusted HR 2.40, 95% CI 2.24 to 2.57) and an increased hazard of aortic aneurysms (HR 2.72, 95% CI 2.53 to 2.93; adjusted HR2.24, 95% CI 2.02 to 2.49) that were substantially greater in magnitude than the association of these outcomes with amoxicillin. The hazard of retinal detachment was marginal (HR 1.28, 95% CI 0.99 to 1.65; adjusted HR 1.47, 95% CI 1.08 to 2.00) and not greater in magnitude than that observed with amoxicillin.

CONCLUSIONS

Fluoroquinolones are associated with subsequent tendon ruptures and may also contribute to aortic aneurysms.

Fluoroquinolone-induced serious, persistent, multisymptom adverse effects

We present a case series of four previously healthy, employed adults without significant prior medical history in each of whom symptoms developed while on fluoroquinolones (FQs), with progression that continued following discontinuation evolving to a severe, disabling multisymptom profile variably involving tendinopathy, muscle weakness, peripheral neuropathy, autonomic dysfunction, sleep disorder, cognitive dysfunction and psychiatric disturbance. Physicians and patients should be alert to the potential for FQ-induced severe disabling multisymptom pathology that may persist and progress following FQ use. Known induction by FQs of delayed mitochondrial toxicity provides a compatible mechanism, with symptom profiles (and documented mechanisms of FQ toxicity) compatible with the hypothesis of an exposure-induced mitochondrial neurogastrointestinal encephalomyopathy.

Antimicrobial Stewardship Programs in Inpatient Hospital Settings: A Systematic Review

Objective

Evaluate the evidence for effects of inpatient antimicrobial stewardship programs (ASPs) on patient, prescribing, and microbial outcomes.

Design

Systematic review.

Methods

Search of MEDLINE (2000 through November 2013), Cochrane Library, and reference lists of relevant studies. We included English language studies with patient populations relevant to the United States (ie, infectious conditions and prescriptions required for antimicrobials) that evaluated ASP interventions and reported outcomes of interest. Study characteristics and outcomes data were extracted and reviewed by investigators and trained research personnel.

Results

Few intervention types (eg, audit and feedback, guideline implementation, and decision support) substantially impacted patient outcomes, including mortality, length of stay, readmission, or incidence ofClostridium difficileinfection. However, most interventions were not powered adequately to demonstrate impacts on patient outcomes. Most interventions were associated with improved prescribing patterns as measured by decreased antimicrobial use or increased appropriate use. Where reported, ASPs were generally associated with improvements in microbial outcomes, including institutional resistance patterns or resistance in the study population. Few data were provided on harms, sustainability, or key intervention components. Studies were typically of short duration, low in methodological quality, and varied in study design, populations enrolled, hospital setting, ASP intent, intervention composition and implementation, comparison group, and outcomes assessed.

Conclusions

Numerous studies suggest that ASPs can improve prescribing and microbial outcomes. Strength of evidence was low, and most studies were not designed adequately to detect improvements in mortality or other patient outcomes, but obvious adverse effects on patient outcomes were not reported.

Does variation among provincial drug formulary antimicrobial listings in Canada influence prescribing rates?

BACKGROUND

The financial accessibility of antimicrobial drugs to the outpatient community in Canada is governed at the provincial level through formularies. Each province may choose to list particular drugs or impose restriction criteria on products in order to guide prescribing and/or curtail costs. Although changes to formularies have been shown to change patterns in the use of individual products and alter costs, no comparison has been made among the provincial antimicrobial formularies with regards to flexibility/stringency, or an assessment of how these formularies impact overall antimicrobial use in the provinces.

OBJECTIVES

To summarize provincial antimicrobial formularies and assess whether their relative flexibility/stringency had a statistical impact upon provincial prescription volume during a one year period.

METHODS

Provincial drug plan formularies were accessed and summarized for all prescribed antimicrobials in Canada during 2010. The number of general and restricted benefits for each plan was compiled by antimicrobial classification. Population-adjusted prescription rates for all individual antimicrobials and by antimicrobial class were obtained from the Canadian Integrated Program for Antimicrobial Resistance Surveillance. Correlations between the number of general benefits, restricted benefits, and total benefits with the prescription rate in the provinces were assessed by Spearman rank correlation coefficients.

RESULTS

Formularies varied considerably among the Canadian provinces. Quebec had the most flexible formulary, offering the greatest number of general benefits and fewest restrictions. In contrast, Saskatchewan's formulary displayed the lowest number of general benefits and most restrictions. Correlation analyses detected a single significant result; macrolide prescription rates decreased as the number of general macrolide benefits increased. All other rates of provincial antimicrobial prescribing and measures of flexibility/stringency revealed no significant correlations.

CONCLUSIONS

Although antimicrobial formulary listings are used to guide prescribing rates within a province, our analysis of one year's data of the impact of the antimicrobial formulary structure did not correlate with antimicrobial prescribing rates, and other factors are likely to be at play.

Antimicrobial stewardship programs in inpatient hospital settings: a systematic review

OBJECTIVE

Evaluate the evidence for effects of inpatient antimicrobial stewardship programs (ASPs) on patient, prescribing, and microbial outcomes.

DESIGN

Systematic review.

METHODS

Search of MEDLINE (2000 through November 2013), Cochrane Library, and reference lists of relevant studies. We included English language studies with patient populations relevant to the United States (ie, infectious conditions and prescriptions required for antimicrobials) that evaluated ASP interventions and reported outcomes of interest. Study characteristics and outcomes data were extracted and reviewed by investigators and trained research personnel.

RESULTS

Few intervention types (eg, audit and feedback, guideline implementation, and decision support) substantially impacted patient outcomes, including mortality, length of stay, readmission, or incidence of Clostridium difficile infection. However, most interventions were not powered adequately to demonstrate impacts on patient outcomes. Most interventions were associated with improved prescribing patterns as measured by decreased antimicrobial use or increased appropriate use. Where reported, ASPs were generally associated with improvements in microbial outcomes, including institutional resistance patterns or resistance in the study population. Few data were provided on harms, sustainability, or key intervention components. Studies were typically of short duration, low in methodological quality, and varied in study design, populations enrolled, hospital setting, ASP intent, intervention composition and implementation, comparison group, and outcomes assessed.

CONCLUSIONS

Numerous studies suggest that ASPs can improve prescribing and microbial outcomes. Strength of evidence was low, and most studies were not designed adequately to detect improvements in mortality or other patient outcomes, but obvious adverse effects on patient outcomes were not reported.

The impact of drug reimbursement policy on rates of testosterone replacement therapy among older men

Background

Despite a lack of data describing the long-term efficacy and safety of testosterone replacement therapy (TRT), prescribing of testosterone to older men has increased with the availability of topical formulations. The magnitude of this increase and the impact of formulary restrictions on testosterone prescribing are poorly characterized.

Methods

We conducted a time series analysis using the linked health administrative records of men aged 66 years or older in Ontario, Canada between January 1, 1997 and March 31, 2012. We used interventional autoregressive integrated moving average models to examine the impact of a restrictive drug reimbursement policy on testosterone prescribing and examined the demographic profile of men initiating testosterone in the final 2 years of the study period.

Results

A total of 28,477 men were dispensed testosterone over the study period. Overall testosterone prescribing declined 27.9% in the 6 months following the implementation of the restriction policy (9.5 to 6.9 men per 1000 eligible; p<0.01). However, the overall decrease was temporary and testosterone use exceeded pre-policy levels by the end of the study period (11.0 men per 1000 eligible), largely driven by prescriptions for topical testosterone (4.8 men per 1000 eligible). Only 6.3% of men who initiated testosterone had a documented diagnosis of hypogonadism, the main criteria for TRT reimbursement according to the new policy.

Conclusion

Government-imposed restrictions did not influence long-term prescribing of testosterone to older men. By 2012, approximately 1 in every 90 men aged 66 or older was being treated with TRT, most with topical formulations.

Medication transitions and polypharmacy in older adults following acute care

Background/objective

Medication changes at transitions of care and polypharmacy are growing concerns that adversely impact optimal drug use. We aimed to describe transitions and patterns of medication use before and 1 year after older patients were hospitalized for community-acquired pneumonia, the second-most common reason for admission in North America.

Materials and methods

This was an analysis of a population-based clinical registry of patients treated in any of the six hospitals or seven emergency departments in Edmonton, Alberta, Canada, comprising 2,105 patients 65 years and older with community-acquired pneumonia who had survived at least 1 year. The prevalence of polypharmacy (five or more unique prescription drugs), as well as new use and persistence of common drug classes were assessed.

Results

The mean age was 78 years (standard deviation 8 years), 50% were female, 62% were hospitalized, and 58% had severe pneumonia. Among the 2,105 patients, 949 (45%) were using five or more medications prior to hospitalization, increasing to 1,559 (74%) within 90 days postdischarge and remaining over 70% at 1 year. Overall, 1,690 (80%) patients newly started and 1,553 (74%) patients stopped at least one medication in the first 90 days of follow-up. The prevalence of the most common drug classes (ie, cardiovascular, alimentary/metabolism) remained stable, with the exception of anti-infective agents, whereby 25% of patients were dispensed an anti-infective agent 3 months to 1 year after hospitalization.

Conclusion

Most older patients with pneumonia are subject to polypharmacy, and almost every patient had a medication started or stopped during 1-year follow-up, with 25% using antibiotics again. The period following an episode of pneumonia represents an opportunity potentially to optimize pharmacotherapy.

Safety considerations of fluoroquinolones in the elderly: an update

The fluoroquinolones ciprofloxacin, levofloxacin, moxifloxacin and gemifloxacin are widely used for the treatment of various types of bacterial infections. Overall, these antibacterial agents can be considered safe and well tolerated drugs. Comparative studies have evaluated the use of quinolones in elderly and younger populations. Although age per se does not seem to decrease their tolerability, specific adverse effects of the quinolones must be considered when they are chosen for antibacterial treatment. Renal function declines consistently with age and doses of renally excreted quinolones (e.g. ofloxacin, levofloxacin, gatifloxacin) need to be adjusted if a clinically relevant reduction of creatinine clearance is identified. Reactions of the gastrointestinal tract, such as nausea, dyspepsia, vomiting or diarrhoea, are among the most often registered adverse drug reactions during therapy with fluoroquinolones. Treatment with a quinolone causes diarrhoea less frequently than treatment with other classes of antimicrobials. Conflicting data have been published with respect to the incidence of Clostridium difficile-associated diarrhoea in quinolone-treated patients. Hypersensitivity reactions, often manifested on the skin, occur less commonly during therapy with quinolones than, for example, during therapy with beta-lactam antibacterials. Adverse reactions of the CNS are of particular concern in the elderly population. Given the CNS excitatory effects of quinolones, elderly patients should be monitored carefully for such symptoms. It is likely that many signs of possible adverse reactions, such as confusion, weakness, loss of appetite, tremor or depression, are often mistakenly attributed to old age and remain unreported. Quinolones should be used with caution in patients with known or suspected CNS disorders that predispose to seizures (e.g. severe cerebral arteriosclerosis or epilepsy). Quinolones can cause QT interval prolongation. They should be avoided in patients with known prolongation of the QT interval, patients with uncorrected hypokalaemia or hypomagnesaemia and patients receiving class IA (e.g. quinidine, procainamide) or class III (e.g. amiodarone, sotalol) antiarrhythmic agents. Tendinitis and tendon ruptures are recognized as quinolone-induced adverse effects that can occur during treatment or as late as several months after treatment. Chronic renal diseases, concomitant use of corticosteroids and age >60 years are known risk factors for quinolone-induced tendopathies. Overall, the specific adverse-effect profile of quinolones must be considered when they are chosen for treatment of bacterial infections. Because of physiological changes in renal function and when certain co-morbidities are present, some special considerations are necessary when elderly patients are treated with these drugs.

Good research practices for comparative effectiveness research: defining, reporting and interpreting nonrandomized studies of treatment effects using secondary data sources: the ISPOR Good Research Practices for Retrospective Database Analysis Task Force Report--Part I

OBJECTIVES

Health insurers, physicians, and patients worldwide need information on the comparative effectiveness and safety of prescription drugs in routine care. Nonrandomized studies of treatment effects using secondary databases may supplement the evidence based from randomized clinical trials and prospective observational studies. Recognizing the challenges to conducting valid retrospective epidemiologic and health services research studies, a Task Force was formed to develop a guidance document on state of the art approaches to frame research questions and report findings for these studies.

METHODS

The Task Force was commissioned and a Chair was selected by the International Society for Pharmacoeconomics and Outcomes Research Board of Directors in October 2007. This Report, the first of three reported in this issue of the journal, addressed issues of framing the research question and reporting and interpreting findings.

RESULTS

The Task Force Report proposes four primary characteristics-relevance, specificity, novelty, and feasibility while defining the research question. Recommendations included: the practice of a priori specification of the research question; transparency of prespecified analytical plans, provision of justifications for any subsequent changes in analytical plan, and reporting the results of prespecified plans as well as results from significant modifications, structured abstracts to report findings with scientific neutrality; and reasoned interpretations of findings to help inform policy decisions.

CONCLUSIONS

Comparative effectiveness research in the form of nonrandomized studies using secondary databases can be designed with rigorous elements and conducted with sophisticated statistical methods to improve causal inference of treatment effects. Standardized reporting and careful interpretation of results can aid policy and decision-making.

Antibiotic prescribing patterns and hospital admissions with respiratory and urinary tract infections

OBJECTIVE

To explore the relationship between antibiotic prescribing indicators for assessing the prescribing quality of general practitioners (GPs) and populations' health outcome indicators.

DESIGN

Descriptive cross-sectional study.

SETTING

Aljarafe Primary Health Care Area (population 321,034) under the administrative jurisdiction of the Andalusian Public Health Care Service, Spain. In total, 162 GPs, representing 95.29% of the total number of GPs in the study area, were included in the analysis.

METHODS

Antibiotic prescribing indicators based on clinical evidence and recommendations from local resistance patterns were chosen by the consensus group technique. Hospital admissions due to respiratory tract and urinary infections in the three hospitals of the study area were recorded. Multiple regression analysis was carried out to determine the relationship between community prescribing of antibiotics and hospital admissions due to serious complications from respiratory and urinary infections.

RESULTS

The higher prescribing of antibiotics adjusted for patients and working days was associated with a significantly higher number of adjusted hospital admissions due complications arising from respiratory and urinary infections (p < 0.001) (R (2) = 0.142). This relationship was not found for indicators based on the relative prescribing of recommended first-line versus second and third-line antibiotics. There were fewer patients of women GPs admitted to hospitals (p = 0.021).

CONCLUSIONS

Our findings show a statistically significant relationship-at the GPs level-between the quantitative antibiotic prescribing rate and standardized hospital admissions due to complications arising from respiratory and urinary infections of the assisted patients. Strategies should be addressed to reduce unnecessary antibiotic prescribing in primary care.