Applying a correction procedure to the prevalence estimates of overweight and obesity in the German part of the HBSC study

Background: Prevalence rates for overweight and obesity based on self-reported height and weight are underestimated, whereas the prevalence rate for underweight is slightly overestimated. Therefore a correction is needed. Aim of this study is to apply correction procedures to the prevalence rates developed on basis of (self-reported and measured) data from the representative German National Health Interview and Examination Survey for Children and Adolescents (KiGGS) to (self-reported) data from the German Health Behaviour in School Aged Children (HBSC) study to determine whether correction leads to higher prevalence estimates of overweight and obesity as well as lower prevalence rates for underweight. Methods: BMI classifications based on self-reported and measured height and weight from a subsample of the KiGGS study (2,565 adolescents aged 11–15) were used to estimate two different correction formulas. The first and the second correction function are described. Furthermore, the both formulas were applied to the prevalence rates from the HBSC study (7,274 adolescents aged 11–15) which are based on self-reports collected via self-administered questionnaires. Results: After applying the first correction function to self-reported data of the HBSC study, the prevalence rates of overweight and obesity increased from 5.5% to 7.8% (compared to 10.4% in the KiGGS study) and 2.7% to 3.8% (compared to 7.8% in the KiGGS study), respectively, whereas the corrected prevalence rates of underweight and severe underweight decreased from 8.0% to 6.7% (compared to 5.7% in the KiGGS study) and from 5.5% to 3.3% (compared to 2.4% in the KiGGS study), respectively. Application of the second correction function, which additionally considers body image, led to further slight corrections with an increase of the prevalence rates for overweight to 7.9% and for obese to 3.9%. Conclusion: Subjective BMI can be used to determine the prevalence of overweight and obesity among children and adolescents. Where there is evidence of bias, the prevalence estimates should be corrected using conditional probabilities that link measured and subjectively assessed BMI from a representative validation study. These corrections may be improved further by considering body image as an additional influential factor

Measuring adolescents' HRQoL via self reports and parent proxy reports: an evaluation of the psychometric properties of both versions of the KINDL-R instrument

<p>Abstract</p> <p>Background</p> <p>Several instruments are available to assess children's health-related quality of life (HRQoL) based on self reports as well as proxy reports from parents. Previous studies have found only low-to-moderate agreement between self and proxy reports, but few studies have explicitly compared the psychometric qualities of both. This study compares the reliability, factorial validity and convergent and known group validity of the self-report and parent-report versions of the HRQoL KINDL-R questionnaire for children and adolescents.</p> <p>Methods</p> <p>Within the nationally representative cross-sectional German Health Interview and Examination Survey for Children and Adolescents (KiGGS), 6,813 children and adolescents aged 11 to 17 years completed the KINDL-R generic HRQoL instrument while their parents answered the KINDL proxy version (both in paper-and-pencil versions). Cronbach's alpha and confirmatory factor-analysis models (linear structural equation model) were obtained. Convergent and discriminant validity were assessed by calculating the Pearson's correlation coefficient for the Strengths and Difficulties Questionnaire. Known-groups differences were examined (ANOVA) for obese children and children with a lower familial socio-economic status.</p> <p>Results</p> <p>The parent reports achieved slightly higher Cronbach's alpha values for the total score (0.86 vs. 0.83) and most sub-scores. Confirmatory factor analysis revealed an acceptable fit of the six-dimensional measurement model of the KINDL for the parent (RMSEA = 0.07) and child reports (RMSEA = 0.06). Factorial invariance across the two versions did not hold with regards to the pattern of loadings, the item errors and the covariation between latent concepts. However the magnitude of the differences was rather small. The parent report version achieved slightly higher convergent validity (r = 0.44 – 0.63 vs. r = 0.33 – 0.59) in the Strengths and Difficulties Questionnaire. No clear differences were observed for known-groups validity.</p> <p>Conclusion</p> <p>Our study showed that parent proxy reports and child self reports on the child's HRQoL slightly differ with regards to how the perceptions, evaluations and possibly the affective resonance of each group are structured and internally consistent. Overall, the parent reports achieved slightly higher reliability and thus are favoured for the examination of small samples. No version was universally superior with regards to the validity of the measurements. Whenever possible, children's HRQoL should be measured via both sources of information.</p

Die KiGGS-Studie

Von 2003 bis 2006 wurde die KiGGS-Basiserhebung (Baseline) in insgesamt 167 Städten und Gemeinden in Deutschland mit einer geclusterten Zufallsstichprobe von 17.641 Kindern und Jugendlichen im Alter von 0 bis 17 Jahren und ihren Eltern durchgeführt. Dabei wurden die Kinder und Jugendlichen medizinisch-physikalisch untersucht und getestet sowie die Eltern, ab elf Jahren auch die Kinder und Jugendlichen selbst, zu körperlichen, psychischen und sozialen Aspekten ihrer Gesundheit befragt. Im Rahmen des bundesweiten Gesundheitsmonitorings am Robert Koch-Institut (RKI) wird die Studie als prospektive Kohortenstudie mit einem Abstand von etwa fünf Jahren zwischen zwei Messzeitpunkten weitergeführt, wobei die Stichprobe durch die Einbeziehung jüngerer Jahrgänge zu jedem Messzeitpunkt querschnittlich ergänzt wird. Die Erhebung in der Kernstudie basiert auf einem Eckwertekonzept zu wesentlichen Indikatoren der körperlichen, psychischen und sozialen Gesundheit, das durch vertiefende Erhebungen beziehungsweise Untersuchungen an Teilstichproben im Rahmen von Kooperationen mit externen wissenschaftlichen Einrichtungen modular ergänzt wird. Derzeit befindet sich die erste Wiederholungsbefragung (KiGGS Welle 1) als telefonischer Befragungssurvey noch bis Juni 2012 im Feld. Die Feldphase der zweiten Folgeerhebung (KiGGS Welle 2), die wieder ein Untersuchungs- und Befragungssurvey sein wird, beginnt noch 2013. Mit den bundesweit repräsentativen Daten lassen sich wichtige gesundheitspolitische Fragestellungen beantworten, sowohl mit Blick auf gesundheitliche Trends als auch mit Blick auf längsschnittliche Gesundheitsverläufe. Wichtige Aussagen werden unter anderem in Bezug auf Trends in der Prävalenz von Übergewicht und Adipositas, der Inzidenz von atopischen Erkrankungen oder der Persistenz beziehungsweise Remission von psychischen Auffälligkeiten und Störungen erwartet.From 2003 to 2006 the KiGGS Baseline Study was conducted, including a clustered random sample of 167 sample points and 17,641 children and adolescents from 0 to 17 years, as well as their parents in 167 sample points. The children and adolescents were medically and physically examined, and their parents answered questions about physical, psychological and social aspects of their children’s health, as did, from 11 years on, the children and adolescents themselves. Within the framework of the nationwide health monitoring at the Robert Koch Institute, the KiGGS study is being continued as a prospective cohort study with an interval of approximately 5 years between follow-ups. The study sample will be cross-sectionally refilled with younger age groups at each time of measurement. The assessment of the KiGGS core study follows a core indicator concept, which is modularly complemented by external scientific cooperation partners. The field work of the first wave (KiGGS Wave 1), a telephone survey, will continue until June 2012. The second follow-up (KiGGS Wave 2) will again combine examinations and interviews, starting in 2013. On the basis of the nationally representative KiGGS data, important questions about health policy can be answered, such as trends and trajectories of health. Important results are expected, among others concerning trends in overweight and obesity, the incidence of atopic diseases, and the persistency or remission of psychopathological symptoms and disorders

Erratum to : Updated prevalence rates of overweight and obesity in 11- to 17-year-old adolescents in Germany. Results from the telephone-based KiGGS Wave 1 after correction for bias in self-reports

Background: The nationwide “German Health Interview and Examination Survey for Children and Adolescents” (KiGGS), conducted in 2003–2006, showed an increase in the prevalence rates of overweight and obesity compared to the early 1990s, indicating the need for regularly monitoring. Recently, a follow-up—KiGGS Wave 1 (2009–2012)—was carried out as a telephone-based survey, providing self-reported height and weight. Since self-reports lead to a bias in prevalence rates of weight status, a correction is needed. The aim of the present study is to obtain updated prevalence rates for overweight and obesity for 11- to 17-year olds living in Germany after correction for bias in self-reports. Methods: In KiGGS Wave 1, self-reported height and weight were collected from 4948 adolescents during a telephone interview. Participants were also asked about their body perception. From a subsample of KiGGS Wave 1 participants, measurements for height and weight were collected in a physical examination. In order to correct prevalence rates derived from self-reports, weight status categories based on self-reported and measured height and weight were used to estimate a correction formula according to an established procedure under consideration of body perception. The correction procedure was applied and corrected rates were estimated. Results: The corrected prevalence of overweight, including obesity, derived from KiGGS Wave 1, showed that the rate has not further increased compared to the KiGGS baseline survey (18.9 % vs. 18.8 % based on the German reference). Conclusion: The rates of overweight still remain at a high level. The results of KiGGS Wave 1 emphasise the significance of this health issue and the need for prevention of overweight and obesity in children and adolescents

Erratum to: ‘Updated prevalence rates of overweight and obesity in 11- to 17-year-old adolescents in Germany. Results from the telephone-based KiGGS Wave 1 after correction for bias in self-reports’

BACKGROUND: The nationwide “German Health Interview and Examination Survey for Children and Adolescents” (KiGGS), conducted in 2003–2006, showed an increase in the prevalence rates of overweight and obesity compared to the early 1990s, indicating the need for regularly monitoring. Recently, a follow-up—KiGGS Wave 1 (2009–2012)—was carried out as a telephone-based survey, providing self-reported height and weight. Since self-reports lead to a bias in prevalence rates of weight status, a correction is needed. The aim of the present study is to obtain updated prevalence rates for overweight and obesity for 11- to 17-year olds living in Germany after correction for bias in self-reports. METHODS: In KiGGS Wave 1, self-reported height and weight were collected from 4948 adolescents during a telephone interview. Participants were also asked about their body perception. From a subsample of KiGGS Wave 1 participants, measurements for height and weight were collected in a physical examination. In order to correct prevalence rates derived from self-reports, weight status categories based on self-reported and measured height and weight were used to estimate a correction formula according to an established procedure under consideration of body perception. The correction procedure was applied and corrected rates were estimated. RESULTS: The corrected prevalence of overweight, including obesity, derived from KiGGS Wave 1, showed that the rate has not further increased compared to the KiGGS baseline survey (18.9 % vs. 18.8 % based on the German reference). CONCLUSION: The rates of overweight still remain at a high level. The results of KiGGS Wave 1 emphasise the significance of this health issue and the need for prevention of overweight and obesity in children and adolescents

HuSKY: a healthy nutrition score based on food intake of children and adolescents in Germany

For many epidemiological questions an overall indicator of healthy nutrition can be useful. Based on the data from the FFQ of the German Health Interview and Examination Study for children and adolescents (KiGGS) we developed a healthy nutrition score based on a comparison with current recommendations for children and adolescents. We observed independent and statistically significant relationships between the nutrition score and age, sex, socio-economic status, immigration background, level of urbanisation and residence in former East v. former West Germany. Furthermore, the nutrition score was statistically significantly related to serum concentrations of homocysteine (inverse association) and folate (positive associations). The construction of a healthy nutrition score appears to be useful for several reasons. For instance, our score can be used to summarise an abundance of dietary information to a single measure, to get an overall impression of diets of individuals or groups, which can be useful to detect certain risk groups

The challenge of comprehensively mapping children's health in a nation-wide health survey: Design of the German KiGGS-Study

<p>Abstract</p> <p>Background</p> <p>From May 2003 to May 2006, the Robert Koch Institute conducted the German Health Interview and Examination Survey for Children and Adolescents (KiGGS). Aim of this first nationwide interview and examination survey was to collect comprehensive data on the health status of children and adolescents aged 0 to 17 years.</p> <p>Methods/Design</p> <p>Participants were enrolled in two steps: first, 167 study locations (sample points) were chosen; second, subjects were randomly selected from the official registers of local residents. The survey involved questionnaires filled in by parents and parallel questionnaires for children aged 11 years and older, physical examinations and tests, and a computer assisted personal interview performed by study physicians. A wide range of blood and urine testing was carried out at central laboratories. A total of 17 641 children and adolescents were surveyed – 8985 boys and 8656 girls. The proportion of sample neutral drop-outs was 5.3%. The response rate was 66.6%.</p> <p>Discussion</p> <p>The response rate showed little variation between age groups and sexes, but marked variation between resident aliens and Germans, between inhabitants of cities with a population of 100 000 or more and sample points with fewer inhabitants, as well as between the old West German states and the former East German states. By analysing the short non-responder questionnaires it was proven that the collected data give comprehensive and nationally representative evidence on the health status of children and adolescents aged 0 to 17 years.</p

German cancer statistics 2004

Background: For years the Robert Koch Institute (RKI) has been annually pooling and reviewing the data from the German population-based cancer registries and evaluating them together with the cause-of-death statistics provided by the statistical offices. Traditionally, the RKI periodically estimates the number of new cancer cases in Germany on the basis of the available data from the regional cancer registries in which registration is complete; this figure, in turn, forms the basis for further important indicators. Methods: This article gives a brief overview of current indicators - such as incidence, prevalence, mortality, survival rates - on the most common types of cancer, as well as important ratios on the risks of developing and dying of cancer in Germany. Results: According to the latest estimate, there were a total of 436,500 new cancer cases in Germany in 2004. The most common cancer in men is prostate cancer with over 58,000 new cases per annum, followed by colorectal and lung cancer. In women, breast cancer remains the most common cancer with an estimated 57,000 new cases every year, also followed by colorectal cancer. These and further findings on selected cancer sites can be found in the current brochure on “Cancer in Germany”, which is regularly published by the RKI together with the Association of Population-based Cancer Registries in Germany (GEKID). In addition, the RKI made cancer-prevalence estimates and calculated current morbidity and mortality risks at the federal level for the first time. According to these figures, the 5-year partial prevalence - i.e. the total number of cancer patients diagnosed over the past five years who are currently still living - exceeds 600,000 in men; the figure is about the same among women. Here, too, the most common cancers are prostate cancer in men and breast cancer in women. The lifetime risk of developing cancer, which is more related to the individual, is estimated to be higher among men (48.5%) than among women (40.3%). In roughly rounded figures, therefore, about every second person in Germany develops cancer in the course of their lives. One in four men and one in five women die of cancer. Conclusions: In recent years, population-based cancer registration in Germany has come significantly closer to the aim of the complete, nationwide coverage of cancer. The continuous improvements in the data situation help describe cancer development in Germany