Angelika Schaffrath Rosario

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

BackgroundFrom 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.Methods/DesignParticipants 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%.DiscussionThe 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.

German health interview and examination survey for adults (DEGS) - design, objectives and implementation of the first data collection wave

BackgroundThe German Health Interview and Examination Survey for Adults (DEGS) is part of the recently established national health monitoring conducted by the Robert Koch Institute. DEGS combines a nationally representative periodic health survey and a longitudinal study based on follow-up of survey participants. Funding is provided by the German Ministry of Health and supplemented for specific research topics from other sources.Methods/designThe first DEGS wave of data collection (DEGS1) extended from November 2008 to December 2011. Overall, 8152 men and women participated. Of these, 3959 persons already participated in the German National Health Interview and Examination Survey 1998 (GNHIES98) at which time they were 18–79 years of age. Another 4193 persons 18–79 years of age were recruited for DEGS1 in 2008–2011 based on two-stage stratified random sampling from local population registries. Health data and context variables were collected using standardized computer assisted personal interviews, self-administered questionnaires, and standardized measurements and tests. In order to keep survey results representative for the population aged 18–79 years, results will be weighted by survey-specific weighting factors considering sampling and drop-out probabilities as well as deviations between the design-weighted net sample and German population statistics 2010.DiscussionDEGS aims to establish a nationally representative data base on health of adults in Germany. This health data platform will be used for continuous health reporting and health care research. The results will help to support health policy planning and evaluation. Repeated cross-sectional surveys will permit analyses of time trends in morbidity, functional capacity levels, disability, and health risks and resources. Follow-up of study participants will provide the opportunity to study trajectories of health and disability. A special focus lies on chronic diseases including asthma, allergies, cardiovascular conditions, diabetes mellitus, and musculoskeletal diseases. Other core topics include vaccine-preventable diseases and immunization status, nutritional deficiencies, health in older age, and the association between health-related behavior and mental health.

Potential determinants of obesity among children and adolescents in Germany: results from the cross-sectional KiGGS study

BackgroundObesity among children and adolescents is a growing public health problem. The aim of the present paper is to identify potential determinants of obesity and risk groups among 3- to 17-year old children and adolescents to provide a basis for effective prevention strategies.MethodsData were collected in the German Health Interview and Examination Survey for Children and Adolescents (KiGGS), a nationally representative and comprehensive data set on health behaviour and health status of German children and adolescents. Body height and weight were measured and body mass index (BMI) was classified according to IOTF cut-off points. Statistical analyses were conducted on 13,450 non-underweight children and adolescents aged 3 to 17 years. The association between overweight, obesity and several potential determinants was analysed for this group as well as for three socio-economic status (SES) groups. A multiple logistic regression model with obesity as the dependent variable was also calculated.ResultsThe strongest association with obesity was observed for parental overweight and for low SES. Furthermore, a positive association with both overweight (including obesity) and obesity was seen for maternal smoking during pregnancy, high weight gain during pregnancy (only for mothers of normal weight), high birth weight, and high media consumption. In addition, high intakes of meat and sausages, total beverages, water and tea, total food and beverages, as well as energy-providing food and beverages were significantly associated with overweight as well as with obesity. Long sleep time was negatively associated with obesity among 3- to 10-year olds. Determinants of obesity occurred more often among children and adolescents with low SES.ConclusionParental overweight and a low SES are major potential determinants of obesity. Families with these characteristics should be focused on in obesity prevention.

Die Verbreitung von Übergewicht und Adipositas bei Kindern und Jugendlichen in Deutschland. Ergebnisse des bundesweiten Kinder- und Jugendgesundheitssurveys (KiGGS)

ZusammenfassungÜbergewicht und Adipositas sind ein wachsendes gesundheitliches Problem. Bislang gab es für Kinder und Jugendliche jedoch keine repräsentativen altersspezifischen Aussagen zur Verbreitung des Problems in Deutschland. Im Rahmen des bundesweiten Kinder- und Jugendgesundheitssurveys (KiGGS) wurden die Teilnehmer im Studienzentrum standardisiert gemessen und gewogen. Zur Definition von Übergewicht und Adipositas wurden die von Kromeyer-Hauschild et al. vorgelegten Referenzdaten zur Verteilung des Body-Mass-Index (BMI) zugrunde gelegt. Damit liegen erstmalig repräsentative Informationen zur Verbreitung von Übergewicht und Adipositas vor: 15% der Kinder und Jugendlichen von 3–17 Jahren haben einen BMI oberhalb des 90. Perzentils der Referenzdaten und sind damit übergewichtig. Eine Untergruppe davon, nämlich 6,3% aller 3- bis 17-Jährigen, leidet nach dieser Definition unter Adipositas, da ihr BMI oberhalb des 97. Perzentils der Referenzdaten liegt. Der Anteil der Übergewichtigen steigt von 9% bei den 3- bis 6-Jährigen über 15% bei den 7- bis 10-Jährigen bis hin zu 17% bei den 14- bis 17-Jährigen. Die Verbreitung von Adipositas beträgt bei den 3- bis 6-Jährigen 2,9% und steigt über 6,4% bei den 7- bis 10-Jährigen bis auf 8,5% bei den 14- bis 17-Jährigen. Klare Unterschiede zwischen Jungen und Mädchen oder zwischen den alten und neuen Bundesländern sind nicht zu erkennen. Ein höheres Risiko für Übergewicht und Adipositas besteht bei Kindern aus Familien mit niedrigem Sozialstatus, bei Kindern mit Migrationshintergrund und bei Kindern, deren Mütter ebenfalls übergewichtig sind.AbstractOverweight and obesity are an increasing problem: worldwide, for Germany and for children and adolescents. Until now there have been no representative and age-specific assessments of the prevalence of obesity among children and adolescents in Germany. Thus, the standardised height and weight measurements gathered in the German Health Interview and Examination Survey for Children and Adolescents (KiGGS) have, for the first time, provided national, representative data about overweight and obesity in young people. The terms ‘overweight’ and ‘obese’ are defined based on percentiles of the body mass index (BMI) of the Kromeyer-Hauschild reference system. Of children and adolescents between the ages of 3 and 17, 15% exceed the 90th BMI percentile of the reference data and are thus overweight, 6.3% exceed the 97th BMI percentile and thus suffer from obesity by this definition. The proportion of overweight rises from 9% of 3–6-year-olds to 15% of 7–10-year-olds and 17% of 14–17-year-olds. The prevalence of obesity is 2.9%, 6.4% and 8.5% for the same age groups respectively. No clear differences between boys and girls or between East and West Germany are detected. Children are at a higher risk of being overweight or obese if they have a lower socioeconomic status, have a migration background, or have mothers who are also overweight.

Body mass index percentiles for children and adolescents in Germany based on a nationally representative sample (KiGGS 2003―2006)

Objective:To present body mass index (BMI) percentiles representative for children in Germany and to compare them with the currently used percentiles by Kromeyer–Hauschild (KH) and international percentiles of the World Health Organisation (WHO) and the International Obesity Task Force (IOTF).Methods:Representative examination survey of 17 641 children and adolescents aged 0–17 years living in Germany (KiGGS 2003–2006 study, response rate 67%) with standardized measurement of height and weight.Results:Generally, BMI in KiGGS was higher than in the reference populations from previous decades. KiGGS shows an asymmetric upward shift of the BMI distribution from about age 6 years and an earlier adiposity rebound compared with KH. The BMI peak in the first year of life is shown by KiGGS and WHO, but much less by KH. The cut-offs for overweight and obesity determined with the IOTF methodology in KiGGS (percentiles corresponding to BMI 25 and 30 kg/m2 at 18 years of age) were similar to IOTF cut-offs from age 18 to 10 years but systematically lower for younger children.Conclusions:The KiGGS BMI percentiles appear more valid for Germany than present alternatives and should be used for population monitoring. Despite their methodological limitations, the general shape of the older German KH references is confirmed by KiGGS for the ages 2–17 years. In order not to obscure the increase in obesity rates in the last decades, we therefore propose to continue using KH for individual diagnosis and estimation of the prevalence of overweight and obesity in this age range.

Hypertension prevalence, awareness, treatment and control in Germany 1998 and 2008–11

Germany was reported to have higher blood pressure (BP) and lower awareness, treatment and control of BP than other western countries based on 1998 data. BP distribution and hypertension management were examined for 1998 and 2008–11 in 7108 adult participants of the German National Health Interview and Examination Survey 1998 (GNHIES98) and in 7095 adult participants the German Health Interview and Examination Survey for Adults 2008–11 (DEGS1) aged 18–79 years. Age- and sex-standardized mean systolic BP (SBP) dropped from 129.0 to 124.1 mm Hg (women 127.3–120.8, men 130.7–127.4), mean diastolic BP (DBP) from 78.3 to 73.2 mm Hg (women 78.0–71.2, men 78.5–75.3). Mean SBP and DBP decreased most in treated hypertensives but were also lower in participants without hypertension. The overall prevalence of hypertension, including controlled hypertension, remained almost unchanged (30% vs 32%). Uncontrolled hypertension (BP⩾140/90 mm Hg) decreased from 23% to 15% (women 22–13%, men 24–18%). Among hypertensives, awareness increased from 69% to 82% (women 74–87%, men 65–78%), treatment increased from 55% to 72% (women 62–79%, men 48–65%) and control increased from 23% to 51% (women 25–58%, men 20–45%). However, men aged 18–29 years had an opposite trend with 1.5 mm Hg higher SBP and increased prevalence of hypertension, which was mostly uncontrolled. These findings suggest that BP has decreased substantially in Germany, while leaving a persistent gender gap in management and room for further improvement of prevention and treatment, particularly in men.

German height references for children aged 0 to under 18 years compared to WHO and CDC growth charts

Aim: The objective is to present height-for-age percentiles representative for infants, children, and adolescents in Germany and to compare them with older German height references by Kromeyer-Hauschild which are based on heterogeneous pooled data (KH) and with international growth charts from the Centers for Disease Control (CDC) as well as the growth standard and the growth reference of the World Health Organization (WHO). Subjects and methods: The reference population consists of a nationally representative sample of 17 079 children and adolescents aged 0–17 years (KiGGS study 2003–2006) with standardized height measurements. Height reference curves were created using Coles LMS method. To compare KiGGS with other reference systems, KiGGS height values were transformed to SD-scores using the KH, WHO and CDC references. Results: Height-for-age percentiles in KiGGS increase until age 16 years in girls and until the end of the observed age range (17.98 years) for boys. In general, boys are taller than girls, except for the age range 10.5–13.0 years. The difference in height between boys and girls is negligible before puberty and reaches 13 cm at age 17.98 years. KiGGS and KH percentiles differ only slightly. However, there are substantial differences in SD-score levels between KiGGS on the one hand and WHO and CDC on the other hand, KiGGS generally being higher, especially in the extreme percentiles. Conclusion: The KiGGS height-for-age references can be recommended as a national height reference for screening and monitoring growth in infants (starting from 4 months of age), children and adolescents in Germany. In German samples, the WHO and CDC references can be used for international comparisons.

Gestational weight gain and overweight in children: Results from the cross-sectional German KiGGS study

Abstract Objective. Gestational weight gain (GWG) has been associated with overweight in offspring. The aim of the study was to assess the association of GWG with childhood overweight and a potential effect modification by maternal BMI. Methods. In a cross-sectional study of 10 784 children aged 3 to 17 years from the German national child health survey (2003-2006), main outcome measure was overweight defined by the criteria of the International Obesity Task Force. Main exposure was GWG in data-derived categories. Results. Crude and adjusted odds ratios (OR) for high and low GWG with average GWG as a reference were calculated in logistic regression models. With adjustment for potential confounders, the OR of childhood overweight for high GWG was 1.16 (95% confidence interval [CI]: 1.02, 1.32), whereas for low GWG the adjusted OR was not significant at 1.01 (95% CI: 0.89, 1.15). Stratified analyses by estimated pre-pregnancy BMI revealed inconsistent effects of high GWG on childhood overweight, with a significantly increased risk for children of normal-weight mothers only. No statistically significant advantageous effect of low GWG was present for any of the maternal BMI subgroups. Conclusion. A high compared with an average GWG accounts for a moderate increase in the risk of offspring overweight, whereas a lower than average GWG does not appear to reduce this risk. Subgroup analyses suggested that the beneficial effect of avoidance of high GWG might be confined to normal-weight mothers. Interventions promoting healthy GWG should not only target overweight and obese, but also normal-weight females.

Nationally representative waist circumference percentiles in German adolescents aged 11.0–18.0 years

OBJECTIVE The aim of this study was to develop age- and sex-specific percentile curves for waist circumference (WC) in German adolescents. METHODS A cross-sectional population-based study (German Health Interview and Examination Survey for Children and Adolescents [KiGGS]) was carried out in a large nationally representative sample of 3 345 males and 3 221 females aged 11.0 to 18.0 years from May 2003 to May 2006. Smoothed percentile curves of WC were derived by the LMS method. RESULTS Girls had lower WC values than boys at any age and percentile. WC increased with age in both boys and girls. The curves show a fairly linear pattern for males, but for females they begin to level off after the age of 13 years. CONCLUSIONS The presented WC percentile curves are based on a representative sample of adolescents living in Germany and standardized measurements. We propose their use for clinical practice to monitor abdominal obesity in adolescents, although there is a need for future studies correlating cut-offs with health outcomes. The German curves could contribute to the feasibility of combining representative data from several countries to establish an international reference for WC.

Abdominal obesity in German adolescents defined by waist-to-height ratio and its association to elevated blood pressure: the KiGGS study.

Objective: The aim of this study was to compare the fixed 0.5 cut-off and the age- and sex-specific 90th percentile (P90) for waist-to-height ratio (WHtR) in German adolescents with respect to the prevalence of abdominal obesity and to compare the screening ability of WHtR and BMI to identify hypertensive blood pressure (BP) values. Methods: Between 2003 and 2006, the German Health Interview and Examination Survey for Children and Adolescents (KiGGS) was carried out including 3,492 boys and 3,321 girls aged 11-17 years. Abdominal obesity was assessed by two WHtR cut-points (P90; 0.5). Hypertensive BP was defined as BP exceeding age-, sex- and height-specific 95th percentiles or the adult threshold for hypertension (140/90 mm Hg). Results: Agreement between the WHtR cut-offs was very good (Kappa 0.89 for boys; 0.81 for girls), and the prevalence of abdominal obesity was slightly higher using P90 (boys 12.0%; girls 11.3%) compared to 0.5 (boys 10.7%; girls 8.0%). WHtR and BMI-for-age had equivalent ability to discriminate hypertensive BP (ROC-AUC < 0.7; sensitivity of the 0.5 cut-off for detecting hypertensive BP < 30%). Conclusion: The fixed 0.5 WHtR cut-off can be used in German adolescents to characterize abdominal obesity. However, WHtR is not suitable as a screening tool for hypertensive BP in adolescents.