Samuel Coenen

European Surveillance of Antimicrobial Consumption (ESAC): outpatient antibiotic use in Europe

BACKGROUND Data on more than a decade of outpatient quinolone use were collected from 33 European countries within the European Surveillance of Antimicrobial Consumption (ESAC) project, funded by the European Centre for Disease Prevention and Control (ECDC). METHODS For the period 1997-2009, data on outpatient use of systemic quinolones aggregated at the level of the active substance were collected using the Anatomical Therapeutic Chemical (ATC)/defined daily dose (DDD) method (WHO, version 2011), and expressed in DDD and packages per 1000 inhabitants per day (DID and PID, respectively). Using a classification based on pharmacokinetic and in vitro potency profiles, quinolone use was analysed with regard to trends over time, seasonal variation and composition. RESULTS Total outpatient quinolone use in 2009 varied by a factor of 7.5 between the country with the highest (Italy, 3.61 DID) and the country with the lowest (the UK, 0.48 DID) quinolone use. The second-generation quinolones accounted for >50% of quinolone use (mainly ciprofloxacin), except for Croatia, where first-generation quinolones (mainly norfloxacin) were mostly used. A significant increase in outpatient quinolone use was found for Europe, as well as a large seasonal variation, which increased significantly over time from 1997 to 2009. Relative use of third-generation quinolones significantly increased over time with respect to the use of second-generation quinolones, while the relative use of both significantly increased with respect to the first-generation quinolones. Levofloxacin and moxifloxacin (respiratory quinolones) represented >10% of quinolone outpatient use in 17 countries, with extreme seasonal variation in all countries. CONCLUSIONS There was a substantial increase and change in the pattern of quinolone use between 1997 and 2009, a period during which quinolones that are effective for the treatment of respiratory tract infections were introduced. These quinolones are not the first-line antibiotics for this indication and their use should generally be limited, and quinolones should ideally show no substantial seasonal variation in terms of their use.

Helicobacter pylori resistance to antibiotics in Europe and its relationship to antibiotic consumption

Objective Resistance to antibiotics is the major cause of treatment failure of Helicobacter pylori infection. A study was conducted to assess prospectively the antibacterial resistance rates of H pylori in Europe and to study the link between outpatient antibiotic use and resistance levels in different countries. Design Primary antibiotic resistance rates of H pylori were determined from April 2008 to June 2009 in 18 European countries. Data on yearly and cumulative use over several years of systemic antibacterial agents in ambulatory care for the period 2001–8 were expressed in Defined Daily Doses (DDD) per 1000 inhabitants per day. The fit of models and the degree of ecological association between antibiotic use and resistance data were assessed using generalised linear mixed models. Results Of 2204 patients included, H pylori resistance rates for adults were 17.5% for clarithromycin, 14.1% for levofloxacin and 34.9% for metronidazole, and were significantly higher for clarithromycin and levofloxacin in Western/Central and Southern Europe (>20%) than in Northern European countries (<10%). Model fit improved for each additional year of antibiotic use accumulated, but the best fit was obtained for 2005. A significant association was found between outpatient quinolone use and the proportion of levofloxacin resistance (p=0.0013) and between the use of long-acting macrolides only and clarithromycin resistance (p=0.036). Conclusion In many countries the high rate of clarithromycin resistance no longer allows its empirical use in standard anti-H pylori regimens. The knowledge of outpatient antibiotic consumption may provide a simple tool to predict the susceptibility of H pylori to quinolones and to macrolides and to adapt the treatment strategies.

Effect of azithromycin and clarithromycin therapy on pharyngeal carriage of macrolide-resistant streptococci in healthy volunteers: a randomised, double-blind, placebo-controlled study

BACKGROUND Resistance to antibiotics is a major public-health problem, and studies that link antibiotic use and resistance have shown an association but not a causal effect. We used the macrolides azithromycin and clarithromycin to investigate the direct effect of antibiotic exposure on resistance in the oral streptococcal flora of healthy volunteers. METHODS Volunteers were treated with azithromycin (n=74), clarithromycin (74), or placebo (76) in a randomised, double-blind trial. Pharyngeal swabs were obtained before and after administration of study treatment through 180 days. The proportion of streptococci that were macrolide resistant was assessed and the molecular basis of any change in resistance investigated. Analyses were done on an intent-to-treat basis. This study is registered with ClinicalTrials.gov, number NCT00354952. FINDINGS The number of dropouts (n=20) was much the same in all groups until day 42; dropouts increased substantially at day 180 (105). Both macrolides significantly increased the proportion of macrolide-resistant streptococci compared with the placebo at all points studied, peaking at day 8 in the clarithromycin group (mean increase 50.0%, 95% CI 41.7-58.2; p<0.0001) and at day 4 in the azithromycin group (53.4%, 43.4-63.5; p<0.0001). The proportion of macrolide-resistant streptococci was higher after azithromycin treatment than after clarithromycin use, with the largest difference between the two groups at day 28 (17.4% difference, 9.2-25.6; p<0.0001). Use of clarithromycin, but not of azithromycin, selected for the erm(B) gene, which confers high-level macrolide resistance. INTERPRETATION This study shows that, notwithstanding the different outcomes of resistance selection, macrolide use is the single most important driver of the emergence of macrolide resistance in vivo. Physicians prescribing antibiotics should take into account the striking ecological side-effects of such antibiotics.

Variation in antibiotic prescribing and its impact on recovery in patients with acute cough in primary care: prospective study in 13 countries

Objective To describe variation in antibiotic prescribing for acute cough in contrasting European settings and the impact on recovery. Design Cross sectional observational study with clinicians from 14 primary care research networks in 13 European countries who recorded symptoms on presentation and management. Patients followed up for 28 days with patient diaries. Setting Primary care. Participants Adults with a new or worsening cough or clinical presentation suggestive of lower respiratory tract infection. Main outcome measures Prescribing of antibiotics by clinicians and total symptom severity scores over time. Results 3402 patients were recruited (clinicians completed a case report form for 99% (3368) of participants and 80% (2714) returned a symptom diary). Mean symptom severity scores at presentation ranged from 19 (scale range 0 to 100) in networks based in Spain and Italy to 38 in the network based in Sweden. Antibiotic prescribing by networks ranged from 20% to nearly 90% (53% overall), with wide variation in classes of antibiotics prescribed. Amoxicillin was overall the most common antibiotic prescribed, but this ranged from 3% of antibiotics prescribed in the Norwegian network to 83% in the English network. While fluoroquinolones were not prescribed at all in three networks, they were prescribed for 18% in the Milan network. After adjustment for clinical presentation and demographics, considerable differences remained in antibiotic prescribing, ranging from Norway (odds ratio 0.18, 95% confidence interval 0.11 to 0.30) to Slovakia (11.2, 6.20 to 20.27) compared with the overall mean (proportion prescribed: 0.53). The rate of recovery was similar for patients who were and were not prescribed antibiotics (coefficient −0.01, P<0.01) once clinical presentation was taken into account. Conclusions Variation in clinical presentation does not explain the considerable variation in antibiotic prescribing for acute cough in Europe. Variation in antibiotic prescribing is not associated with clinically important differences in recovery. Trial registration Clinicaltrials.gov NCT00353951.

Comparison of outpatient systemic antibacterial use in 2004 in the United States and 27 European countries

The European Surveillance of Antimicrobial Consumption (ESAC) project collects data on antibacterial use in Europe, applying the Anatomic Therapeutic Chemical classification system and defined daily dose methodology, as recommended by the World Health Organization. Comparable data for the United States have been collected from IMS Health. The IMS Health sales data, processed according to ESAC methodology, suggest that outpatient antibacterial use in the United States is high (only 3 of 27 European countries used more) and is mainly characterized by a shift towards newer antibiotics.

European Surveillance of Antimicrobial Consumption (ESAC): quality indicators for outpatient antibiotic use in Europe

Background and objective: Indicators to measure the quality of healthcare are increasingly used by healthcare professionals and policy makers. In the context of increasing antimicrobial resistance, this study aimed to develop valid drug-specific quality indicators for outpatient antibiotic use in Europe, derived from European Surveillance of Antimicrobial Consumption (ESAC) data. Methods: 27 experts (15 countries), in a European Science Foundation workshop, built on the expertise within the European Drug Utilisation Research Group, the General Practice Respiratory Infections Network, the ESCMID Study Group on Primary Care Topics, the Belgian Antibiotic Policy Coordination Committee, the World Health Organization, ESAC, and other experts. A set of proposed indicators was developed using 1997–2003 ESAC data. Participants scored the relevance of each indicator to reducing antimicrobial resistance, patient health benefit, cost effectiveness and public health policy makers (scale: 1 (completely disagree) to 9 (completely agree)). The scores were processed according to the UCLA-RAND appropriateness method. Indicators were judged relevant if the median score was not in the 1–6 interval and if there was consensus (number of scores within the 1–3 interval was fewer than one third of the panel). From the relevant indicators providing overlapping information, the one with the highest scores was selected for the final set of quality indicators—values were updated with 2004 ESAC data. Results: 22 participants (12 countries) completed scoring of a set of 22 proposed indicators. Nine were rated as relevant antibiotic prescribing indicators on all four dimensions; five were rated as relevant if only relevance to reducing antimicrobial resistance and public health policy makers was taken into account. A final set of 12 indicators was selected. Conclusion: 12 of the proposed ESAC-based quality indicators for outpatient antibiotic use in Europe have face validity and are potentially applicable. These indicators could be used to better describe antibiotic use in ambulatory care and assess the quality of national antibiotic prescribing patterns in Europe.

Effects of internet-based training on antibiotic prescribing rates for acute respiratory-tract infections: a multinational, cluster, randomised, factorial, controlled trial

Summary Background High-volume prescribing of antibiotics in primary care is a major driver of antibiotic resistance. Education of physicians and patients can lower prescribing levels, but it frequently relies on highly trained staff. We assessed whether internet-based training methods could alter prescribing practices in multiple health-care systems. Methods After a baseline audit in October to December, 2010, primary-care practices in six European countries were cluster randomised to usual care, training in the use of a C-reactive protein (CRP) test at point of care, in enhanced communication skills, or in both CRP and enhanced communication. Patients were recruited from February to May, 2011. This trial is registered, number ISRCTN99871214. Results The baseline audit, done in 259 practices, provided data for 6771 patients with lower-respiratory-tract infections (3742 [55·3%]) and upper-respiratory-tract infections (1416 [20·9%]), of whom 5355 (79·1%) were prescribed antibiotics. After randomisation, 246 practices were included and 4264 patients were recruited. The antibiotic prescribing rate was lower with CRP training than without (33% vs 48%, adjusted risk ratio 0·54, 95% CI 0·42–0·69) and with enhanced-communication training than without (36% vs 45%, 0·69, 0·54–0·87). The combined intervention was associated with the greatest reduction in prescribing rate (CRP risk ratio 0·53, 95% CI 0·36–0·74, p<0·0001; enhanced communication 0·68, 0·50–0·89, p=0·003; combined 0·38, 0·25–0·55, p<0·0001). Interpretation Internet training achieved important reductions in antibiotic prescribing for respiratory-tract infections across language and cultural boundaries. Funding European Commission Framework Programme 6, National Institute for Health Research, Research Foundation Flanders.

A systematic review of the evidence on the effectiveness and risks of inactivated influenza vaccines in different target groups

PURPOSE To systematically review the evidence regarding the efficacy, effectiveness and risks of the use of inactivated influenza vaccines in children, healthy adults, elderly individuals and individuals with co-morbidities such as diabetes, chronic lung disease, cardiovascular disease, kidney or liver disease and immune suppression. METHODS The Cochrane database of systematic reviews was searched for relevant reviews and supplemented with searches of the Cochrane Central Register of Controlled Trials database and Medline. Two reviewers independently assessed review and trial quality and extracted data. RESULTS AND CONCLUSIONS The inactivated influenza vaccine has been proven effective in preventing laboratory-confirmed influenza among healthy adults (16-65 years) and children (≥6 years) (GRADE A evidence). However, there is strikingly limited good-quality evidence (all GRADE B, C or not existing) of the effectiveness of influenza vaccination on complications such as pneumonia, hospitalisation and influenza-specific and overall mortality. Inconsistent results are found in studies among children younger than 6 years, individuals with COPD, institutionalised elderly (65 years or older), elderly with co-morbidities and healthcare workers in elderly homes, which can only be explained by bias of unknown origin. The vaccination of pregnant women might be beneficial for their newborns, and vaccination of children might be protective in non-recipients of the vaccine of all ages living in the same community (one RCT, Grade B evidence).

Use of serum C reactive protein and procalcitonin concentrations in addition to symptoms and signs to predict pneumonia in patients presenting to primary care with acute cough: diagnostic study

Objectives To quantify the diagnostic accuracy of selected inflammatory markers in addition to symptoms and signs for predicting pneumonia and to derive a diagnostic tool. Design Diagnostic study performed between 2007 and 2010. Participants had their history taken, underwent physical examination and measurement of C reactive protein (CRP) and procalcitonin in venous blood on the day they first consulted, and underwent chest radiography within seven days. Setting Primary care centres in 12 European countries. Participants Adults presenting with acute cough. Main outcome measures Pneumonia as determined by radiologists, who were blind to all other information when they judged chest radiographs. Results Of 3106 eligible patients, 286 were excluded because of missing or inadequate chest radiographs, leaving 2820 patients (mean age 50, 40% men) of whom 140 (5%) had pneumonia. Re-assessment of a subset of 1675 chest radiographs showed agreement in 94% (κ 0.45, 95% confidence interval 0.36 to 0.54). Six published “symptoms and signs models” varied in their discrimination (area under receiver operating characteristics curve (ROC) ranged from 0.55 (95% confidence interval 0.50 to 0.61) to 0.71 (0.66 to 0.76)). The optimal combination of clinical prediction items derived from our patients included absence of runny nose and presence of breathlessness, crackles and diminished breath sounds on auscultation, tachycardia, and fever, with an ROC area of 0.70 (0.65 to 0.75). Addition of CRP at the optimal cut off of >30 mg/L increased the ROC area to 0.77 (0.73 to 0.81) and improved the diagnostic classification (net reclassification improvement 28%). In the 1556 patients classified according to symptoms, signs, and CRP >30 mg/L as “low risk” (<2.5%) for pneumonia, the prevalence of pneumonia was 2%. In the 132 patients classified as “high risk” (>20%), the prevalence of pneumonia was 31%. The positive likelihood ratio of low, intermediate, and high risk for pneumonia was 0.4, 1.2, and 8.6 respectively. Measurement of procalcitonin added no relevant additional diagnostic information. A simplified diagnostic score based on symptoms, signs, and CRP >30 mg/L resulted in proportions of pneumonia of 0.7%, 3.8%, and 18.2% in the low, intermediate, and high risk group respectively. Conclusions A clinical rule based on symptoms and signs to predict pneumonia in patients presenting to primary care with acute cough performed best in patients with mild or severe clinical presentation. Addition of CRP concentration at the optimal cut off of >30 mg/L improved diagnostic information, but measurement of procalcitonin concentration did not add clinically relevant information in this group.

European Surveillance of Antimicrobial Consumption (ESAC): disease-specific quality indicators for outpatient antibiotic prescribing

Background In 2007, ESAC (http://www.esac.ua.ac.be) published a set of 12 valid drug-specific quality indicators for outpatient antibiotic use in Europe. In this study, the authors aimed to develop evidence-based disease-specific quality indicators for outpatient antibiotic prescribing in Europe. Methods Two meetings were convened to produce a list of disease-specific quality indicators for outpatient antibiotic prescribing which conform to internationally agreed recommendations, building on a similar development of drug-specific quality indicators, and in collaboration with CHAMP and HAPPY AUDIT. 62 experts were asked to complete two scoring rounds of the proposed indicators on seven dimensions: their relevance to (1) reducing antimicrobial resistance, (2) patient health benefit, (3) cost-effectiveness, (4) policy makers, (5) individual prescribers, (6) their evidence base and (7) their range of acceptable use, using a scale ranging from 1 (=completely disagree) to 9 (=completely agree). Scores were judged according to the UCLA-RAND appropriateness method. Results For the six main indications for antibiotic prescribing (acute otitis media, acute upper-respiratory infection, acute/chronic sinusitis, acute tonsillitis, acute bronchitis/bronchiolitis, cystitis/other urinary infection) and for pneumonia, three quality indicators were proposed, the percentage prescribed (a) antibiotics; (b) recommended antibiotics; (c) quinolones. This set was scored by 40 experts from 25 countries. After one scoring round, all indicators were already rated as relevant on all dimensions, except one. Conclusion All proposed disease-specific quality indicators for outpatient antibiotic prescribing have face validity and are potentially applicable. They could be used to better describe antibiotic use and assess the quality of antibiotic prescribing patterns in ambulatory care.