Bueving, H.J.

Determinants of (sustained) overweight and complaints in children and adolescents in primary care: The DOERAK cohort study design (Article)

2012-09-17T00:00:00Z

Background: Almost half of the adult Dutch population is currently overweight and the prevalence of overweight children is rising at alarming rates as well. Obese children consult their general practitioner (GP) more often than normal weight children. The Dutch government has assigned a key role to the GP in the prevention of overweight. The DOERAK cohort study aims to clarify differences between overweight and non-overweight children that consult the GP; are there differences in number of consultations and type and course of complaints? Is overweight associated with lower quality of life or might this be influenced by the type of complaint? What is the activity level of overweight children compared to non-overweight children? And is (sustained) overweight of children associated with parameters related to the energy balance equation? Methods/Design: A total of 2000 overweight (n = 500) and non-overweight children (n = 1500) aged 2 to 18 years who consult their GP, for any type of complaint in the South-West of the Netherlands are included. At baseline, height, weight and waist circumference are measured during consultation. The number of GP consultations over the last twelve months and accompanying diagnoses are acquired from the medical file. Complaints, quality of life and parameters related to the energy balance equation are assessed with an online questionnaire children or parents fill out at home. Additionally, children or parents keep a physical activity diary during the baseline week, which is validated in a subsample (n = 100) with an activity monitor. Parents fill out a questionnaire about demographics, their own activity behaviour and perceptions on dietary habits and activity behaviour, health and weight status of their child. The physical and lifestyle behaviour questions are repeated at 6, 12 and 24 months follow-up. The present study is a prospective observational cohort in a primary care setting. Discussion: The DOERAK cohort study is the first prospective study that investigates a large cohort of overweight and non-overweight children in primary care. The total study population is expected to be recruited by 2013, results will be available in 2015.

Determinants of (sustained) overweight and complaints in children and adolescents in primary care: The DOERAK cohort study design (Article)

2012-09-17T00:00:00Z

Teachers' ideas versus experts' descriptions of 'the good teacher' in postgraduate medical education: Implications for implementation. A qualitative study (Article)

2011-06-30T00:00:00Z

Background: When innovations are introduced in medical education, teachers often have to adapt to a new concept of what being a good teacher includes. These new concepts do not necessarily match medical teachers' own, often strong beliefs about what it means to be a good teacher. Recently, a new competency-based description of the good teacher was developed and introduced in all the Departments of Postgraduate Medical Education for Family Physicians in the Netherlands. We compared the views reflected in the new description with the views of teachers who were required to adopt the new framework. Methods. Qualitative study. We interviewed teachers in two Departments of Postgraduate Medical Education for Family Physicians in the Netherlands. The transcripts of the interviews were analysed independently by two researchers, who coded and categorised relevant fragments until consensus was reached on six themes. We investigated to what extent these themes matched the new description. Results: Comparing the teachers' views with the concepts described in the new competency-based framework is like looking into two mirrors that reflect clearly dissimilar images. At least two of the themes we found are important in relation to the implementation of new educational methods: the teachers' identification and organisational culture. The latter plays an important role in the development of teachers' ideas about good teaching. Conclusions: The main finding of this study is the key role played by the teachers' feelings regarding their professional identity and by the local teaching culture in shaping teachers' views and expectations regarding their work. This suggests that in implementing a new teaching framework and in faculty development programmes, careful attention should be paid to teachers' existing identification model and the culture that fostered it.

What is the role of virus vaccination in patients with asthma? (Article)

2007-04-01T00:00:00Z

It is estimated that viruses play a role in 30% to 80% of asthma exacerbations. Thus, virus vaccination in patients with asthma could play an important role in preventing asthma exacerbations and other complications. Influenza is the only agent for which a routine vaccine is currently available. This article discusses whether influenza vaccination in patients with asthma, based on the available evidence, is justified. Cost-effectiveness of (influenza) vaccination for patients with asthma is questionable. For the other major viruses involved, the present state of affairs is described. Although progress is being made, a vaccine may be available in the near future only for respiratory syncytial virus (RSV). Meanwhile, clinicians and patients should aim for an optimal treatment with the currently available asthma medication. Copyright

Influenza vaccination in children with asthma (Doctoral Thesis)

2005-04-06T00:00:00Z

Every year, outbreaks of in.uenza appear across the world and cause substantial morbidity and mortality in the general population, particularly in persons with underlying conditions including asthma. Because the in.uenza virus changes constantly, man’s acquired immunity is usually only partial and therefore the population will always to a greater or lesser extent be susceptible. In asthmatics, in.uenza causes upper respiratory tract infections that frequently trigger exacerbations. Large population-based studies have estimated the morbidity and the risk of developing clinical complications in people with asthma. During in.uenza periods, hospitalisation, drug prescriptions and visits to physicians increase, and asthma exacerbations and pneumonia have been reported as the most common complications. Children with asthma are at a higher risk for complications than adults. Reasons to vaccinate asthmatics are the prevention of in.uenza-related illness and complications, including asthma exacerbations and death. However, the protective effect of in.uenza vaccination in asthmatic patients is still disputed. So far no unequivocal bene.cial effect of in.uenza vaccination in asthmatics was found in observational and experimental studies in the sense of reduction of asthma exacerbations and of other complications. Although opinions on the clinical effectiveness of in.uenza vaccination in asthmatic patients are currently based on consensus and indirect evidence, the guidelines of most Western countries advise to vaccinate patients with asthma. As a result, in asthma care, in.uenza vaccination is considered to be a cornerstone for quality of care. Despite these recommendations only a minority of asthma patients is vaccinated worldwide. Reasons for this are fear among patients that vaccination could cause in.uenza, and doubts about bene.ts and effectiveness of in.uenza vaccination amongst physicians and patients. Aim of this thesis is to provide evidence to either support or modify the policy of vaccinating asthmatic patients as is described in most western guidelines. I will focus on children, because in children asthma is the most important reason for in.uenza vaccination and asthma is the most frequent chronic disease in childhood. In chapter 2 we report on the available knowledge of the incidence of in.uenza, the natural course and the burden of disease. Incidence .gures are a prerequisite to reliably forecast the impact of preventive measures for in.uenza and calculate the number needed to treat in order to prevent one additional case of in.uenza. Likewise, incidence .gures are also needed to estimate the number of participants for preventive or therapeutic trials. We conducted a systematic review to estimate the incidence of in.uenza and concomitant morbidity and mortality in children 0 through 19 years (0-19 years). We searched for observational studies and placebo or non treated arms of experimental studies for information on laboratory proven in.uenza illness. From a total of 2758 papers, 356 papers were reviewed on the basis of abstract or title. Sixteen papers were added searching the reference list of these papers. Finally 28 studies met inclusion criteria. They showed a varying incidence of in.uenza with .gures up to 46%. However, when looking at two long term observational studies and averaging seasonal .uctuations, the overall incidence of in.uenza in children was found to be between 5% (children aged 0-19 years) and 9.5% (children aged 0-5 years) per year. Serious morbidity was seldom reported. In the studies selected we found no cases of mortality. Our conclusion is that, given the average incidence for in.uenza found, the selflimited character of the disease, the mild associated morbidity and the rare cases of mortality in children, one can question if in.uenza in children at a population level is a major public health problem. As a result of this outcome we advise that preventive strategies for children should be reconsidered. When investigating preventive strategies for in.uenza one should be led by the average incidence and include more seasons. In chapters 3-6 we present various results of our randomised double-blind placebo-controlled trial in 696 children with asthma, aged 6-18 years. Parenteral vaccination with inactivated in.uenza vaccine or placebo took place approximately November 1st, and children were followed until April 1st of the next year. Local and systemic symptoms, possibly as a result of vaccination, and airway symptoms were reported in a diary. Symptoms scored during the .rst week after vaccination were considered to be adverse effects of the vaccination. When symptom scores reached a prede.ned level, a pharyngeal swab was taken and spirometry was performed. One week later a quality of life questionnaire was administered. Primary outcome was the number of asthma exacerbations associated with virologically proven in.uenza infection. Three hundred forty-nine children were assigned placebo, and 347 were assigned vaccine. In chapter 3, we address the adverse effects of in.uenza vaccination, especially on asthma. Because there is a constant debate that in.uenza vaccination may provoke an asthma exacerbation, a decisive answer to these doubts may affect vaccination rate. During the .rst week after vaccination, participants recorded local, in.uenza like and asthma symptoms as well as use of medication, health care use and absenteeism. As reported in previous studies, vaccine recipients reported redness and stiffness of the arm much more often than placebo recipients. For symptoms of in.uenza like illness, fever, headache and myalgia showed smaller though signi.cant differences during the .rst season, as did hoarseness during the second season, all favouring placebo. These differences may be an expression of the difference between strains used in the vaccine during the two seasons or may be a result of a difference between populations studied in the two in.uenza seasons. Except for cough during the day in the .rst season, favouring placebo, there were no differences indicating that vaccination exacerbates asthma. We conclude that in.uenza vaccination does not seem to exacerbate asthma and can be given safely to asthmatic children. In the literature there is little evidence that in.uenza vaccination reduces asthma exacerbations. In chapter 4 we report the main results of our randomised doubleblind placebo-controlled trial in asthmatic children regarding the preventive effect of in.uenza vaccination on clinical illness, notably asthma exacerbations. Children reported, as described above, airway symptoms in a diary. When symptom scores reached a prede.ned level, a pharyngeal swab was taken. Primary outcome was the number of asthma exacerbations associated with virologically proven in.uenza infection. We considered a reduction in asthma exacerbations of at least 50% as clinically relevant. Three hundred forty-nine children were assigned placebo, and 347 were assigned vaccine. Pharyngeal swabs positive for in.uenza were related to 42 asthma exacerbations, 24 in the vaccine group and 18 in the placebo group, a difference of 33% favouring placebo (31% after adjustment for confounders; 95% con.dence interval, –34% to 161%). In.uenza-related asthma exacerbations were of similar severity in both groups; they lasted 3.1 days shorter in the vaccine group (95% con.dence interval, –6.2 to -0.002 days, p=0.06). We conclude that in.uenza vaccination did not result in a signi.cant reduction of the number, severity, or duration of asthma exacerbations caused by in.uenza. We think additional studies, using in.uenza proven clinical illness as an endpoint, are warranted to justify routine in.uenza vaccination of children with asthma. Health-related quality of life (physical, social and emotional impairments) should be an important measure in evaluations of the management of childhood asthma. Therefore, in chapter 5, the Pediatric Asthma Quality of Life Questionnaire (PAQLQ), a questionnaire in English to de.ne quality of life in asthmatic children, is validated for the Dutch translation. We assessed psychometric properties, responsiveness, and longitudinal and crosssectional construct validity of the Dutch PAQLQ version. The study group consisted of 238 children (6–18 years) with asthma, a subset of children from our trial on in.uenza vaccination, with complete respiratory symptom diaries in the course of one winter season; each child had one (or more) PAQLQ measurement(s) concerning one (or more) week(s) with relatively many symptoms (n=238). Each child also had one PAQLQ measurement concerning another week with relatively few symptoms. The PAQLQ scores of these weeks were compared. Additionally, in a subgroup of the study group that had experienced two or more ‘weeks with many symptoms’ (n=101), we compared the PAQLQ scores for two different weeks with many symptoms of these children. All Cronbach’s a’s of the PAQLQ total score and domains were above 0.70, except for Activities (a=0.54), indicating that the internal consistency of the questions in the questionnaire is moderate to good. Mean PAQLQ scores were signi.cantly different (p <0.01; n=238) between one week with few symptoms and another week with many symptoms. Contrarily, in the subgroup of children with PAQLQ measurements regarding more than a week with many symptoms (n=101), mean PAQLQ scores did not differ signi.cantly (p >0.05) between a week with many symptoms and another week with many symptoms. These results indicate responsiveness of the instrument. Changes in lower respiratory tract symptoms, indicative of asthma severity, correlated better with changes in PAQLQ scores than changes in upper respiratory tract symptoms, which supports the longitudinal and cross-sectional construct validity. The assessed properties of the translation into Dutch were similar to those originally established for the PAQLQ in Canada. This study showed that the Dutch PAQLQ has adequate psychometric properties, excellent responsiveness, and that its longitudinal and cross-sectional construct validity is supported. As this questionnaire has been translated and validated in several languages it is an excellent tool for international and trans-cultural asthma research. In chapter 6 we show the effect of in.uenza vaccination on the well being of asthmatic children. Using PAQLQ, we measured the effects of in.uenza vaccination on physical, emotional and social impairments in asthmatic children. Supplementary we assessed whether in.uenza vaccination has an effect on the corresponding respiratory symptoms and spirometric parameters as well as on all their symptoms throughout the season. Compared to placebo, vaccination improved health-related quality of life in the weeks of illness related to in.uenza-positive swabs. However, no effect was found for respiratory symptoms recorded in the diaries during those weeks. Similarly, no differences were found for quality of life in all weeks of illness or for respiratory symptoms throughout the seasons. Our conclusion is that in.uenza vaccination has a moderate bene.cial effect on quality of life in in.uenza-positive weeks of illness in children with asthma. In chapter 7 we re.ect on our .ndings and conclude that, given the available information on the effectiveness of airway medication; the low overall incidence of in.uenza; the absence of direct evidence for serious complications of in.uenza infection in asthmatic children; the absence of evidence for the clinical effectiveness of in.uenza vaccination in asthmatic children; the absence of adverse effects of in.uenza vaccination and the doubts about cost-effectiveness of this preventive intervention in asthmatic children, guidelines on in.uenza vaccination should be revised and, despite the safety of vaccination, should reconsider the advice to vaccinate children with mild to moderate asthma. Future research should .rst of all focus on long term observational research, spanning more seasons, to determine the real impact of in.uenza in children with and without asthma. Whereas sentinel stations, in cooperation with national in.uenza centres, nowadays provide information on the number of in.uenza like illnesses per number of physicians consultations or at a population level, they could deliver information based on culture con.rmed illness and the burden of disease due to in.uenza in a well de.ned population at risk. Secondly, experiments in which populations in certain regions, covered by sentinel stations, would be asked to participate in vaccination trials, could measure the effect of in.uenza vaccination in the different age and disease categories, including asthma, for which vaccination is advocated but for which insuf.cient evidence for its effectiveness is currently available. In any case, experimental designs should take symptoms of patients on an individual level and symptom based measurements, such as PAQLQ, as an outcome. In this way, the updating of recommendations can be guided by medicine-based evidence wich in turn may improve the effectiveness of recommendations.

Influenza vaccination in asthmatic children: effects on quality of life and symptoms. (Article)

2004-12-01T00:00:00Z

This study aimed to detect the effect of influenza vaccination on quality of life, symptomatology and spirometry in asthmatic children. A randomised double-blind placebo-controlled trial in 696 (296 in 1999-2000 and 400 in 2000-2001) asthmatic children aged 6-18 yrs, which were vaccinated with either vaccine or placebo, was performed. Children participated for only one influenza season. They recorded symptoms in a diary and reported when symptom scores reached a predefined severity level. If this occurred research nurses visited them twice, first to take a pharyngeal swab and spirometry, and a week later to assess quality of life over the past illness week. Compared with placebo, vaccination improved health-related quality of life in the weeks of illness related to influenza-positive swabs. However, no effect was found for respiratory symptoms recorded in the diaries during those weeks. Similarly, no differences were found for quality of life in all weeks of illness or for respiratory symptoms throughout the seasons. Influenza vaccination was found to have a moderately beneficial effect on quality of life in influenza-positive weeks of illness in children with asthma.

Does influenza vaccination exacerbate asthma in children? (Article)

2004-11-15T00:00:00Z

Background: The risks of influenza vaccination in asthmatic children are still being discussed. Especially, the risk that influenza vaccination may exacerbate asthma is an issue in this debate. Methods: We conducted a randomised double-blind placebo-controlled trial in 696 children 6–18 years of age with asthma recruited in general practice during two influenza seasons, 1999–2000 and 2000–2001. Children participated for only one season. During the first week after vaccination, participants recorded local, influenza like and asthma symptoms as well as use of medication, health care use and absenteeism. Results: Except for cough during the day in the first season, favouring placebo, there were no differences indicating that vaccination exacerbates asthma. Conclusions: Influenza vaccination does not seem to exacerbate asthma.

Influenza vaccination in children with asthma: randomized double-blind placebo- controlled trial. (Article)

2004-01-01T00:00:00Z

There is little evidence that influenza vaccination reduces asthma exacerbations. We determined whether influenza vaccination is more effective than placebo in 6-18-year-old children with asthma. We performed a randomized, double-blind, placebo-controlled trial. Parenteral vaccination with inactivated influenza vaccine or placebo took place approximately November 1, and children were followed until April 1 of the next year. Airway symptoms were reported in a diary. When symptom scores reached a predefined level, a pharyngeal swab was taken. Primary outcome was the number of asthma exacerbations associated with virologically proven influenza infection. Three hundred forty-nine children were assigned placebo, and 347 were assigned vaccine. Pharyngeal swabs positive for influenza were related to 42 asthma exacerbations, 24 in the vaccine group and 18 in the placebo group, a difference of 33% favoring placebo (31% after adjustment for confounders; 95% confidence interval, -34% to 161%). Influenza-related asthma exacerbations were of similar severity in both groups; they lasted 3.1 days shorter in the vaccine group (95% confidence interval, -6.2 to 0.002 days, p = 0.06). We conclude that influenza vaccination did not result in a significant reduction of the number, severity, or duration of asthma exacerbations caused by influenza. Additional studies are warranted to justify routine influenza vaccination of children with asthma.