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Samuel Coenen

Publications and source records attributed to Samuel Coenen.

16 recordsLinked to original sources
PubMed2006

The effect of giving influenza vaccination to general practitioners: a controlled trial [NCT00221676].

BACKGROUND: No efficacy studies of influenza vaccination given to GPs have yet been published. Therefore, our purpose was to assess the effect of an inactivated influenza vaccine given to GPs on the rate of clinical respiratory tract infections (RTIs) and proven influenza cases (influenza positive nose and throat swabs and a 4-fold titre rise), while adjusting for important covariates. METHODS: In a controlled trial during two consecutive winter periods (2002-2003 and 2003-2004) we compared (77 and 100) vaccinated with (45 and 40) unvaccinated GPs working in Flanders, Belgium. Influenza antibodies were measured immediately prior to and 3-5 weeks after vaccination, as well as after the influenza epidemic. During the influenza epidemic, GPs had to record their contact with influenza cases and their own RTI symptoms every day. If they became ill, the GPs had to take nose and throat swabs during the first 4 days. We performed a multivariate regression analysis for covariates using Generalized Estimating Equations. RESULTS: One half of the GPs (vaccinated or not) developed an RTI during the 2 influenza epidemics. During the two influenza periods, 8.6% of the vaccinated and 14.7% of the unvaccinated GPs had positive swabs for influenza (RR: 0.59; 95%CI: 0.28 - 1.24). Multivariate analysis revealed that influenza vaccination prevented RTIs and swab-positive influenza only among young GPs (ORadj: 0.35; 95%CI: 0.13 - 0.96 and 0.1; 0.01 - 0.75 respectively for 30-year-old GPs). Independent of vaccination, a low basic antibody titre against influenza (ORadj 0.57; 95%CI: 0.37 - 0.89) and the presence of influenza cases in the family (ORadj 9.24; 95%CI: 2.91 - 29) were highly predictive of an episode of swab-positive influenza. CONCLUSION: Influenza vaccination was shown to protect against proven influenza among young GPs. GPs, vaccinated or not, who are very vulnerable to influenza are those who have a low basic immunity against influenza and, in particular, those who have family members who develop influenza.

Belgium↗
PubMed2006

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

BACKGROUND: Data on outpatient quinolone use in Europe were collected from 25 countries within the ESAC project, funded by DG SANCO of the European Commission, using the WHO ATC/DDD methodology. METHODS: For the period 1997-2003, data on outpatient use of systemic quinolones aggregated at the level of the active substance were collected and expressed in DDD (WHO, version 2004) per 1000 inhabitants per day (DID). Because a new DDD for levofloxacin was published in the ATC 2004 index (0.5 g instead of 0.25 g) all data were recalculated accordingly. Quinolone use was analysed in detail, using a classification into three generations based on their pharmacokinetic and in vitro potency profiles, which determines the area of clinical use. RESULTS: Total outpatient quinolone use in 2003 varied by a factor of 12 between the country with the highest (3.10 DID in Portugal) and lowest (0.25 DID in Denmark) quinolone use. The second-generation quinolones represented more than 50% of the quinolone use (mainly ciprofloxacin) except for Croatia, where the first-generation was used most (mainly norfloxacin). In 22 countries, the use of second and/or third-generation quinolones increased at the expense of the use of first-generation quinolones. The new so-called respiratory quinolones (levofloxacin and moxifloxacin) represented more than 10% of quinolone use in 12 countries, with extreme seasonal variation in all these countries except for one. CONCLUSION: There has been a substantial change in the use pattern of quinolones between 1997 and 2003, since the introduction of quinolones that are effective for the treatment of respiratory tract infections. These quinolones are not the first-line antibiotics for this indication and therefore quinolone use should in general still be limited and not show substantial seasonal variation.

Anti-Bacterial Agents↗
PubMed2006

European Surveillance of Antimicrobial Consumption (ESAC): outpatient macrolide, lincosamide and streptogramin (MLS) use in Europe.

BACKGROUND: Data on outpatient macrolide, lincosamide and streptogramin (MLS) use in Europe were collected from 25 countries within the ESAC project, funded by DG SANCO of the European Commission, using the WHO ATC/DDD methodology. METHODS: For the period 1997-2003, data on outpatient use of systemic MLS aggregated at the level of the active substance were collected and expressed in DDD (WHO, version 2004) per 1000 inhabitants per day (DID). Macrolide use was analysed in detail, using a classification based on their mean plasma elimination half-life. RESULTS: Total outpatient MLS use in 2003 varied by a factor of 11 between the country with the highest (9.36 DID in Greece) and lowest (0.85 DID in Sweden) use. MLS use showed high seasonal variation. Short-, intermediate- and long-acting macrolides were used most in 6, 18 and 1 countries, respectively (mainly erythromycin, clarithromyin and azithromycin, respectively). Lincosamide use was observed in all countries (mainly clindamycin) and substantial streptogramin use only in France (pristinamycin). From 1997 to 2003, MLS use increased in 14 countries and was most pronounced in Greece (increase of >5 DID). Except for Sweden, a relative increase of intermediate- (mainly clarithromycin) and/or long-acting (mainly azithromycin) macrolide use was observed, at the expense of short-acting macrolide (mainly erythromycin) use. CONCLUSION: The observed differences between European countries in the levels of MLS use and the extreme seasonal variations in their use suggest that this class of antibiotics is prescribed inappropriately in many countries. The MLS classification developed here facilitates a more comprehensive description of macrolide use in Europe. These data (collected as part of ESAC) could promote investigations that lead to a deeper understanding of the link between macrolide use and resistance.

Anti-Bacterial Agents↗
PubMed2006

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

BACKGROUND: Data on outpatient cephalosporin use in Europe were collected from 25 countries within the ESAC project, funded by DG SANCO of the European Commission, using the WHO ATC/DDD methodology. METHODS: For the period 1997-2003, data on outpatient use of systemic cephalosporins aggregated at the level of the active substance were collected and expressed in DDD (WHO, version 2004) per 1000 inhabitants per day (DID). Use was analysed in detail, using the new ATC codes J01DB, J01DC, J01DD and J01DE, introduced in the 2005 issue of the WHO ATC index and assigned to the four cephalosporin generations. RESULTS: Total outpatient cephalosporin use in 2003 varied by a factor of 270 between the country with the highest (6.18 DID in Greece) and lowest (0.02 DID in Denmark) use. First-, second- and third-generation cephalosporins were used most in 6, 16 and 3 countries, respectively. We observed fourth-generation use (mainly cefepime) in ambulatory care in 11 countries. From 1997 to 2003 cephalosporin use decreased in 13 countries, in France by more than 1 DID. A relative increase of second-generation (mainly cefuroxime) or third-generation use (mainly cefpodoxime or cefixime) by more than 10% in 12 countries coincided with an equally large decrease of first-generation use in eight countries (mainly cefadroxil, cefalexin or cefatrizine). In six countries, first-generation use increased, second-generation use decreased or both occurred. CONCLUSION: The new ATC codes allow a more detailed description of outpatient cephalosporin use. The variation in antibiotic use in Europe is most extreme for this class of antibiotics, suggesting that in many countries in Europe these antibiotics are prescribed inappropriately.

Anti-Bacterial Agents↗
PubMed2006

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

BACKGROUND: Data on outpatient penicillin use in Europe were collected from 25 countries within the ESAC project, funded by DG SANCO of the European Commission, using the WHO ATC/DDD methodology. METHODS: For the period 1997-2003, data on outpatient use of systemic penicillins aggregated at the level of the active substance were collected and expressed in DDD (WHO, version 2004) per 1000 inhabitants per day (DID). Of the 'Penicillins' (J01C), outpatient use of narrow-spectrum penicillins (J01CE), broad-spectrum penicillins (J01CA), penicillinase-resistant penicillins (J01CF) and combinations with beta-lactamase inhibitors (J01CR) in 25 European countries was analysed in detail. RESULTS: Total outpatient penicillin use in 2003 varied by a factor of 4 between the country with the highest (15.27 DID in Slovakia) and lowest use (3.86 DID in the Netherlands). Narrow-spectrum penicillins, broad-spectrum penicillins and combinations with beta-lactamase inhibitors were used most in 4, 12 and 9 countries, respectively. Penicillin use increased by more than 1 DID in nine countries, whereas it decreased by more than 1 DID in two countries (Czech Republic, France). An increase of the use of combinations with beta-lactamase inhibitors by more than 10% in 10 countries coincided with an equal decrease of broad-spectrum penicillins in seven countries and narrow-spectrum penicillins in three countries. CONCLUSION: Penicillins represent the most widely used antibiotic class in all 25 participating countries; albeit with considerable variation of their use patterns. A distinct shift from narrow-spectrum penicillins to broad-spectrum penicillins, and specifically their combinations with beta-lactamase inhibitors, was observed during the period 1997-2003.

Anti-Bacterial Agents↗
PubMed2006

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

BACKGROUND: The ESAC project, granted by DG SANCO of the European Commission, is an international network of surveillance systems, aiming to collect comparable and reliable data on antibiotic use in Europe. Data on outpatient antibiotic use were collected from 34 countries using the ATC/DDD methodology. METHODS: For the period 1997-2003, data on outpatient use of systemic antibiotics aggregated at the level of the active substance were collected and expressed in DDD (WHO, version 2004) per 1000 inhabitants per day (DID). Outpatient antibiotic (ATC J01) use in 25 European countries, able to deliver valid data, was analysed. RESULTS: Total outpatient antibiotic use in 2003 varied by a factor of 3 between the country with the highest (31.4 DID in Greece) and the country with the lowest (9.8 DID in the Netherlands) use. General use patterns in individual countries as well as trends during the period 1997-2003 are described in this paper, while major antibiotic classes (penicillins, cephalosporins, macrolides/lincosamides/streptogramins and quinolones) will be analysed in detail in separate papers. CONCLUSION: The ESAC project established for the first time a credible alternative to industry sources for the collection of internationally comparable data on antibiotic use in Europe, based on cooperation between regulatory authorities, scientific societies, health insurers and professional organizations. These data provide a tool for assessing public health strategies aiming to optimize antibiotic prescribing.

Anti-Bacterial Agents↗
PubMed2006

Serum antibodies against circulating influenza strains among vaccinated and unvaccinated general practitioners during two consecutive years (2002-2003).

Efficacy studies have not answered the question whether influenza vaccination among general practitioners (GPs) has a substantial additive effect on their immunity. To evaluate this effect the influenza antibody titres in vaccinated and unvaccinated GPs were compared in a controlled trial during two consecutive winter periods (2002-2003 and 2003-2004). The seroprotection rates against the circulating A/H3N2 influenza virus amount to 80% and 42% in the unvaccinated group in 2002 and 2003, respectively. In the vaccinated GPs the seroprotection rate increases from 91% to 96% in 2002 and from 70% to 83% in 2003 after vaccination. Besides vaccination, the (high) basic antibody titre before vaccination and working in a child and family preventive medicine unit were predicting a protective antibody level in GPs.

Antibodies, Viral↗
PubMed2006

Antibiotic prescribing for acute cough: the effect of perceived patient demand.

BACKGROUND: GPs decide whether or not to prescribe antibiotics for acute cough. Apart from clinical signs and symptoms, non-medical reasons influence this decision as well. AIM: To obtain a valid estimate of the effect of perceived patient demand. DESIGN OF STUDY: Secondary analysis of cluster randomised controlled trial data. SETTING: Eighty-five Flemish GPs. METHOD: GPs completed a preprinted form with medical as well as non-medical information and their prescription for 20 consecutive adult patients consulting with acute cough in the periods February to April 2000 and 2001. The effect of perceived patient demand on antibiotic prescribing was estimated by performing alternating logistic regression analysis. A hierarchical backwards elimination procedure, described by Kleinbaum, was used. RESULTS: Seventy-two GPs participated, including 1448 patients eligible for analysis; 500 (34.5%) were prescribed an antibiotic and, according to the GP, 218 (15.1%) asked for an antibiotic. In cases of perceived patient demand antibiotics were prescribed significantly more often (odds ratio [OR] = 4.64, 95% confidence interval [CI] = 2.96 to 7.26). In the final model (n = 819; OR = 4.60, 2.59 to 8.17); Hosmer-Lemeshow goodness-of-fit P = 0.72), the effect of perceived patient demand for an antibiotic depended on the outcome of the lung auscultation. When patient demand was perceived, antibiotics were prescribed significantly more often only in the case of a normal lung auscultation or in the case of only one abnormal auscultatory finding (adjusted OR = 20.83, 95% CI = 8.86 to 48.99; adjusted OR = 4.79; 95% CI = 2.16 to 10.60, respectively). CONCLUSIONS: Perceived patient demand has a significant, independent and clinically relevant effect on antibiotic prescribing for acute cough with negative findings on the lung auscultation. Practice guidelines and interventions to optimise antibiotic prescribing have to take this effect into account.

Acute Disease↗
PubMed2005

Treating patients not diagnoses: challenging assumptions underlying the investigation and management of LRTI in general practice.

OBJECTIVES: Many clinicians treat patients with a lower respiratory tract infection (LRTI) due to bacterial infection with antibiotics, and regard antibiotic treatment as obligatory for patients with radiographic evidence of pneumonia. The necessity of antibiotic treatment is largely unknown and rarely challenged. PATIENTS AND METHODS: Twenty-five general practitioners (GPs) recorded clinical information on 247 adult patients presenting with LRTI. Standard microbiological, susceptibility and serological analysis, and chest radiography was performed for all patients. At 28 days after entry into the study, the GPs took a history and conducted a physical examination again and decided whether or not the patient was fully recovered. RESULTS: Thirty of 63 patients with cultured pathogenic bacteria were either not treated with antibiotics, or treated with an antibiotic to which the cultured bacterium was non-susceptible. All but one recovered spontaneously, although it took more than 28 days for two patients. The other patient recovered with an additional course of antibiotics. Five patients from this cohort with radiological evidence of pneumonia fully recovered without antibiotic treatment. CONCLUSIONS: Not all patients with bacterial LRTI and/or pneumonia require antibiotic treatment in order to recover. Managing the patient rather than treating a diagnosis appears safe and effective in general practice.

Adolescent↗
PubMed2004

Optimizing antibiotic prescribing for acute cough in general practice: a cluster-randomized controlled trial.

OBJECTIVES: To assess the effect of a tailored professional intervention, including academic detailing, on antibiotic prescribing for acute cough. METHODS: In a cluster-randomized controlled before and after study 85 Flemish GPs included adult patients with acute cough consulting in the periods February-April 2000 and 2001. The intervention consisted of a clinical practice guideline for acute cough, an educational outreach visit and a postal reminder to support its implementation in January 2001. Antibiotic prescribing rates and patients' symptom resolution were the main outcome measures. RESULTS: Thirty-six of 42 GPs received the intervention and 35 of 43 GPs served as controls; 1503 patients were eligible for analysis. Only in the intervention group were patients less likely to receive antibiotics after the intervention [OR(adj) (95% CI)=0.56 (0.36-0.87)]. Prescribed antibiotics were also more in line with the guideline in the intervention group [1.90 (0.96-3.75)] and less expensive from the perspective of the National Sickness and Invalidity Insurance Institute [MD(adj) (95% CI)= Euro -6.89 [-11.77-(-2.02)]]. No significant differences were found between the groups for the time to symptom resolution. CONCLUSIONS: An (inter)actively delivered tailored intervention implementing a guideline for acute cough is successful in optimizing antibiotic prescribing without affecting patients' symptom resolution. Further research efforts should be devoted to cost-effectiveness studies of such interventions.

Acute Disease↗
PubMed2004

Management of acute cough: comparisons between Belgian and Dutch GPs.

OBJECTIVES: In Europe there are large variations in overall outpatient antibiotic use, even between two neighbouring countries as Belgium and the Netherlands. We aimed to compare the management of acute cough between Belgian and Dutch general practitioners (GPs). METHODS: In cross-sectional studies in Belgium and the Netherlands, 71 Belgian and 84 Dutch GPs included adult patients consulting for acute cough. Differences in antibiotic prescription rates, the percentage of first-choice antibiotics (i.e. tetracyclines and broad-spectrum penicillins) and bronchodilator prescription rates were assessed by using Generalised Estimates Equations to adjust for clustering of patients within GPs. RESULTS: In Belgium 324/810 patients (40%) were prescribed an antibiotic compared with 101/309 (33%) in the Netherlands (adjusted OR (95% CI) 1.28 (0.91-1.83)). Belgian GPs prescribed fewer first-choice antibiotics compared with Dutch GPs: 124/324 (38%) versus 67/101 (66%) (adjusted OR (95% CI) 0.39 (0.22-0.72)). In both countries, 17% of the patients were prescribed a bronchodilator. CONCLUSIONS: Antibiotic prescription rates for adult patients with acute cough were not significantly higher in Belgian than in Dutch general practice at the 5% significance level. Dutch GPs' antibiotic prescriptions were more in line with national guidelines. Bronchodilator prescription rates were similar. Because Dutch GPs probably encountered more severe cases of acute cough compared with their Belgian colleagues, the observed prescribing differences might be underestimated.

Acute Disease↗
PubMed2002

Antibiotics for coughing in general practice: a questionnaire study to quantify and condense the reasons for prescribing.

BACKGROUND: Antibiotics are being overprescribed in ambulant care, especially for respiratory tract infections (RTIs). Gaining insight into the actual reasons for prescribing remains important for the design of effective strategies to optimise antibiotic prescribing. We aimed to determine items of importance for the antibiotic prescribing decision and to make them operational for an intervention trial. METHODS: A postal questionnaire based upon focus group findings was sent to 316 Flemish general practitioners (GPs). On a verbal rating scale the GPs scored to what extent they consider the questionnaire items in decision making in case of suspected RTI in a coughing patient and how strongly the items support or counter antibiotic treatment. Factor analysis was used to condense the data. The relative importance of the yielded operational factors was assessed using Wilcoxon Matched Pairs test. RESULTS: 59.5% completed the study. Response group characteristics (mean age: 42.8 years; 65.9% men) approximated that of all Flemish GPs. Participants considered all the items included in the questionnaire: always the operational factor 'lung auscultation', often 'whether or not there is something unusual happening' - both medical reasons - and to a lesser extent 'non-medical reasons' (P < 0.001). Non-medical as well as medical reasons support antibiotic treatment, but non-medical reasons to a lesser extent (P < 0.001). CONCLUSION: This study quantified, condensed and confirmed the findings of previous focus group research. Practice guidelines and interventions to optimise antibiotic prescribing have to take non-medical reasons into account.

Adult↗