Nationally representative results on SARS-CoV-2 seroprevalence and testing in Germany at the end of 2020.

Pre-vaccine SARS-CoV-2 seroprevalence data from Germany are scarce outside hotspots, and socioeconomic disparities remained largely unexplored. The nationwide representative RKI-SOEP study (15,122 participants, 18-99 years, 54% women) investigated seroprevalence and testing in a supplementary wave of the Socio-Economic-Panel conducted predominantly in October-November 2020. Self-collected oral-nasal swabs were PCR-positive in 0.4% and Euroimmun anti-SARS-CoV-2-S1-IgG ELISA from dry-capillary-blood antibody-positive in 1.3% (95% CI 0.9-1.7%, population-weighted, corrected for sensitivity = 0.811, specificity = 0.997). Seroprevalence was 1.7% (95% CI 1.2-2.3%) when additionally correcting for antibody decay. Overall infection prevalence including self-reports was 2.1%. We estimate 45% (95% CI 21-60%) undetected cases and lower detection in socioeconomically deprived districts. Prior SARS-CoV-2 testing was reported by 18% from the lower educational group vs. 25% and 26% from the medium and high educational group (p < 0.001, global test over three categories). Symptom-triggered test frequency was similar across educational groups. Routine testing was more common in low-educated adults, whereas travel-related testing and testing after contact with infected persons was more common in highly educated groups. This countrywide very low pre-vaccine seroprevalence in Germany at the end of 2020 can serve to evaluate the containment strategy. Our findings on social disparities indicate improvement potential in pandemic planning for people in socially disadvantaged circumstances.

Seroepidemiological study on the spread of SARS-CoV-2 in Germany: Study protocol of the CORONA-MONITORING bundesweit' study (RKI-SOEP study).

The SARS-CoV-2 coronavirus has spread rapidly across Germany. Infections are likely to be under-recorded in the notification data from local health authorities on laboratory-confirmed cases since SARS-CoV-2 infections can proceed with few symptoms and then often remain undetected. Seroepidemiological studies allow the estimation of the proportion in the population that has been infected with SARS-CoV-2 (seroprevalence) as well as the extent of undetected infections. The 'CORONA-MONITORING bundesweit' study (RKI-SOEP study) collects biospecimens and interview data in a nationwide population sample drawn from the German Socio-Economic Panel (SOEP). Participants are sent materials to self-collect a dry blood sample of capillary blood from their finger and a swab sample from their mouth and nose, as well as a questionnaire. The samples returned are tested for SARS-CoV-2 IgG antibodies and SARS-CoV-2 RNA to identify past or present infections. The methods applied enable the identification of SARS-CoV-2 infections, including those that previously went undetected. In addition, by linking the data collected with available SOEP data, the study has the potential to investigate social and health-related differences in infection status. Thus, the study contributes to an improved understanding of the extent of the epidemic in Germany, as well as identification of target groups for infection protection.

[Reference Values for Cardiorespiratory Fitness of the General Population: The German National Health Interview and Examination Survey for Adults (DEGS1) 2008-2011]. / Referenzwerte für die kardiorespiratorische Fitness der allgemeinen Bevölkerung: Die Studie zur Gesundheit Erwachsener in Deutschland (DEGS1) 2008­2011.

AIM OF STUDY: This study aims to provide population-based reference values for heart rate-based indicators of cardiorespiratory fitness for adults with physical activity readiness aged 18 to 64 years living in Germany. METHODS: Based on data on 2,826 individuals who participated in a submaximal cycle ergometer exercise test as part of the German National Health Interview and Examination Survey for Adults (DEGS1) between 2008 and 2011, we calculated the following indicators: physical working capacity at 150 and 130 beats/min and at 75% of estimated maximum heart rate (PWC150, PWC130 and PWC75%) as well as heart rate-based estimated maximum oxygen uptake (VO2max). We used the LMS method by Cole & Green 1992 to calculate reference values. RESULTS: 25th, 50th and 75th percentiles of PWC150 were 1.5, 1.77 and 2.08 watts/kg among men and 1.18, 1.44 and 1.69 among women. 25th, 50th and 75th percentiles of PWC130 were 1.16, 1.41 and 1.68 watts/kg among men and 0.81, 1.05 and 1.29 among women. Age-dependent median PWC75% values among men and women were 1.87 - age in years× 0.01 and 1.31 - (age in years/100)2× 0.98, respectively, and VO2max among men is 41.7 - age× 0.15. CONCLUSIONS: The references values presented can be used for individual rating of cardiorespiratory fitness among adults living in Germany. Furthermore, they can serve as a basis for regular monitoring purposes.

Serology- and PCR-based cumulative incidence of SARS-CoV-2 infection in adults in a successfully contained early hotspot (CoMoLo study), Germany, May to June 2020.

Three months after a coronavirus disease (COVID-19) outbreak in Kupferzell, Germany, a population-based study (n = 2,203) found no RT-PCR-positives. IgG-ELISA seropositivity with positive virus neutralisation tests was 7.7% (95% confidence interval (CI): 6.5-9.1) and 4.3% with negative neutralisation tests. We estimate 12.0% (95% CI: 10.4-14.0%) infected adults (24.5% asymptomatic), six times more than notified. Full hotspot containment confirms the effectiveness of prompt protection measures. However, 88% naïve adults are still at high COVID-19 risk.

Seroepidemiological study on the spread of SARS-CoV-2 in populations in especially affected areas in Germany - Study protocol of the CORONA-MONITORING lokal study.

At a regional and local level, the COVID-19 pandemic has not spread out uniformly and some German municipalities have been particularly affected. The seroepidemiological data from these areas helps estimate the proportion of the population that has been infected with SARS-CoV-2 (seroprevalence), as well as the number of undetected infections and asymptomatic cases. In four municipalities which were especially affected, 2,000 participants will be tested for an active SARS-CoV-2 infection (oropharyngeal swab) or a past infection (blood specimen IgG antibody test). Participants will also be asked to fill out a short written questionnaire at study centres and complete a follow-up questionnaire either online or by telephone, including information on issues such as possible exposure, susceptability, symptoms and medical history. The CORONA-MONITORING lokal study will allow to determine the proportion of the population with SARS-CoV-2 antibodies in four particularly affected locations. This study will increase the accuracy of estimates regarding the scope of the epidemic, help determine risk and protective factors for an infection and therefore also identify especially exposed groups and, as such, it will be crucial towards planning of prevention measures.

Erratum: Development of overweight and obesity in children. Results of the KiGGS cohort.

[This corrects the article DOI: 10.17886/RKI-GBE-2018-030.2.].

Overweight and obesity among children and adolescents in Germany. Results of the cross-sectional KiGGS Wave 2 study and trends.

For some time, there have been indications that the prevalence of overweight and obesity among children and adolescents in Germany has stabilised at a high level. The second wave of the German Health Interview and Examination Survey for Children and Adolescents (KiGGS Wave 2, 2014-2017) once again provides nationwide measurements on height and weight of children and adolescents aged 3 to 17 years. The results are confirming this trend. The prevalence of overweight is 15.4% and 5.9% for obesity. There are no differences between girls and boys. Overweight and obesity prevalence increases with age. Children and adolescents with low socioeconomic status (SES) are more likely to be overweight and obese than those with high SES. Compared to the KiGGS baseline study (2003-2006), there was no further increase in overweight and obesity prevalence overall and in all age groups.

KiGGS Wave 2 cross-sectional study - participant acquisition, response rates and representativeness.

For the third time, wave 2 of the German Health Interview and Examination Survey for Children and Adolescents (KiGGS), which is conducted in the context of health monitoring at the Robert Koch Institute, now provides representative cross-sectional data for Germany. Completed in 2017, data for the cross-sectional component of KiGGS Wave 2 was collected in the form of an interview and examination survey. Interview survey data was collected from 15,023 participants, meaning that the required number of participants has been reached. A randomly selected subgroup of 3,567 participants was also examined. The overall response rate was 40.1%. Differences in response rates were registered regarding certain sociodemographic characteristics. Weighting was applied to compensate for differences in willingness to participate related to age, gender, geographic region, nationality and education factors. Weighting ensures that assessments of the health of children and adolescents in Germany are representative for the population. The data serves to estimate prevalence rates and, through comparison with the results from previous survey waves, to analyse trends. A set of measures were taken to recruit a sufficiently large group of participants and ensure that the net sample reflects the composition of the overall population to the highest degree. For future surveys, further measures ought to be taken in order to improve the integration of hard-to-reach subgroups.

KiGGS Wave 2 longitudinal component - data collection design and developments in the numbers of participants in the KiGGS cohort.

The German Health Interview and Examination Survey for Children and Adolescents (KiGGS) is conducted within the health monitoring framework that has been established at the Robert Koch Institute (RKI). In addition to regular cross-sectional studies of the current health of children and adolescents living in Germany, KiGGS also includes a longitudinal component - the KiGGS cohort. The longitudinal data, which can be linked individually throughout the various waves of the study, enables developments in health and their associated influencing factors to be analysed during the life course. Participants from the KiGGS baseline study form the baseline of the KiGGS cohort. The baseline study was carried out between 2003 and 2006 as a nationwide interview and examination survey of children and adolescents aged between 0 and 17 years. The KiGGS cohort comprises the 17,641 participants who, after taking part in the baseline study, also agreed to participate in recurring follow-ups that are to continue through adolescence into adulthood. Until now, two follow-up studies have been conducted: KiGGS Wave 1 (2009-2012, n=11,992) and KiGGS Wave 2 (2014-2017), which, in line with the baseline study, was conducted as an interview and examination survey. A total of 10,853 repeat participants were interviewed for KiGGS Wave 2; 6,465 people also took part in an examination. As such, 61.3% of the people who originally participated in the baseline study also provided data from interviews for KiGGS Wave 2. In addition, 50.8% have provided various forms of data for all three of the survey's waves. This data pool can help answer numerous questions from the epidemiological life course discipline regarding the population living in Germany; at the time of the baseline study, these participants were children and adolescents. In order to exploit the full potential of the study for life course research and to be able to trace the health and social development of different generations in the future, the concepts on which the study is based are to be further developed, and innovative strategies for participant retention are to be drawn up.

Prevalence of underweight, overweight and obesity among children and adolescents in Germany. KiGGS Wave 2 results according to international reference systems.

In Germany, the reference system according to Kromeyer-Hauschild is usually used to define underweight, overweight and obesity in children and adolescents. International classification systems to describe prevalence are the reference systems of the World Health Organization (WHO) and the International Obesity Task Force (IOTF). This article reports underweight, overweight and obesity prevalences among children and adolescents according to WHO and IOTF criteria using data from the second wave of the German Health Interview and Examination Survey for Children and Adolescents (KiGGS Wave 2, 2014-2017). According to the WHO reference system, the prevalence of underweight among 5- to 17-year-olds is 1.6%, the prevalence of overweight is 26.3% (including obesity) and the prevalence of obesity is 8.8%. According to IOTF, the prevalence of underweight among 3- to 17-year-olds is 10.0%. The prevalence of overweight (including obesity) is 19.3% and the prevalence of obesity is 4.7%. From a public health point of view, underweight as an indicator of malnutrition plays a rather minor role in Germany. The prevalence of overweight according to WHO is three quarters higher and one quarter higher according to IOTF than the national reference. When comparing the international reference systems, the WHO prevalence is one third higher than IOTF prevalence. According to national and international reference systems, no further increase in the prevalence of overweight and obesity is observed, but the prevalence remain at a high level.

New data for action. Data collection for KiGGS Wave 2 has been completed.

The fieldwork of the second follow-up to the German Health Interview and Examination Survey for Children and Adolescents (KiGGS) was completed in August 2017. KiGGS is part of the Robert Koch Institute's Federal Health Monitoring. The study consists of the KiGGS cross-sectional component (a nationally representative, periodic cross-sectional survey of children and adolescents aged between 0 and 17) and the KiGGS cohort (the follow-up into adulthood of participants who took part in the KiGGS baseline study). KiGGS collects data on health status, health-related behaviour, psychosocial risk and protective factors, health care and the living conditions of children and adolescents in Germany. The first interview and examination survey (the KiGGS baseline study; undertaken between 2003 and 2006; n=17,641; age range: 0-17) was carried out in a total of 167 sample points in Germany. Physical examinations, laboratory analyses of blood and urine samples and various physical tests were conducted with the participants and, in addition, all parents and participants aged 11 or above were interviewed. The first follow-up was conducted via telephone-based interviews (KiGGS Wave 1 2009-2012; n=11,992; age range: 6-24) and an additional sample was included (n=4,455; age range: 0-6). KiGGS Wave 2 (2014-2017) was conducted as an interview and examination survey and consisted of a new, nationwide, representative cross-sectional sample of 0- to 17-year-old children and adolescents in Germany, and the second KiGGS cohort follow-up. The completion of the cross-sectional component of KiGGS Wave 2 means that the health of children and adolescents in Germany can now be assessed using representative data gained from three study waves. Trends can therefore be analysed over a period stretching to over ten years now. As the data collected from participants of the KiGGS cohort can be individually linked across the various surveys, in-depth analyses can be conducted for a period ranging from childhood to young adulthood and developmental processes associated with physical and mental health and the associated risk and protective factors can be explored. As such, KiGGS Wave 2 expands the resources available to health reporting, as well as policy planning and research, with regard to assessing the health of children and adolescents in Germany.

Time Trends in Cardiometabolic Risk Factors in Adults.

BACKGROUND: Data from three representative health examination surveys in Germany were analyzed to examine secular trends in the prevalence and magnitude of cardiometabolic risk factors. METHODS: The target variables were the following cardiometabolic risk factors: lack of exercise, smoking, obesity, systolic blood pressure, total cholesterol, serum glucose, self-reported high blood pressure, hyperlipidemia, and diabetes, and the use of antihypertensive, cholesterol-lowering, and antidiabetic drugs. 9347 data sets from men and 10 068 from women were analyzed. The calculated means and prevalences were standardized to the age structure of the German population as of 31 December 2010 and compared across the three time periods of the surveys: 1990-1992, 1997-1999, and 2008-11. RESULTS: Over the entire period of observation (1990-2011), the mean systolic blood pressure fell from 137 to 128 mmHg in men and from 132 to 120 mmHg in women; the mean serum glucose concentration fell from 5.6 to 5.3 mmol/L in men and from 5.4 to 5.0 mmol/l in women; and the mean total cholesterol level fell from 6.2 to 5.3 mmol/L in both sexes. In men, smoking and lack of exercise became less common. On the other hand, the prevalence of use of antidiabetic, cholesterol-lowering, and antihypertensive drugs rose over the same time period, as did that of self-reported diabetes. The first of the three surveys (1990-1992) revealed differences between persons residing in the former East and West Germany in most of the health variables studied; these differences became less marked over time, up to the last survey in 2008-2011. CONCLUSION: The cardiometabolic risk profile of the German adult population as a whole improved over a period of 20 years. Further in-depth analyses are now planned.

Prevalence, trends, patterns and associations of analgesic use in Germany.

BACKGROUND: Despite the public health relevance of analgesic use, large-scale studies on this topic in Germany are lacking. This study describes the prevalence, trends, associations and patterns of use of prescription and over-the-counter (OTC) analgesics, focusing on five of the most common agents: aspirin, diclofenac, ibuprofen, naproxen and paracetamol. METHODS: Data from two representative population-based surveys: The German National Health Interview and Examination Survey 1998 (GNHIES98 n = 7099) and the German Health Interview and Examination Survey for Adults 2008-2011 (DEGS1 n = 7091) was investigated. Information on all medicines consumed in the previous 7 days was collected via computer-assisted personal interviews with adults aged 18-79 years. Associations between analgesic use and socio-demographic and health-behaviour factors were analysed using logistic regression models. RESULTS: Analgesic use has increased over the last decade from 19 to 21%. This was exclusively due to the rise in OTC analgesic use from 10.0 to 12.2%. Prescribed analgesic use remained constant (7.9%). Findings from DEGS1 indicate that ibuprofen is the most commonly used analgesic followed by aspirin and paracetamol. OTC analgesic use is higher among women and smokers, but lower among older adults (65-79 years). Prescribed analgesics use is higher among women, older adults, smokers and obese adults with medium or high socio- economic status. Adults performing more than 2 h/week of physical exercise use fewer analgesics. DISCUSSION: Among the adult population of Germany, the prevalence of OTC analgesic use has significantly increased over the last decade. We found differences between adults consuming OTC and prescribed analgesics (or both) concerning their health behaviour and health conditions. International direct comparison between prevalence rates of analgesic use was limited due to varying availability of analgesics between countries and to methodological differences. CONCLUSIONS: About one in five community dwelling adults aged 18-79 years in Germany use analgesics in a given week. Considering the potential harms of analgesic use, monitoring of prevalence, patterns and determinants of use at the population level are important steps to inform disease prevention and health promotion policies.

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

BACKGROUND: The 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/DESIGN: The 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. DISCUSSION: DEGS 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.

Validity and predictors of BMI derived from self-reported height and weight among 11- to 17-year-old German adolescents from the KiGGS study.

BACKGROUND: For practical and financial reasons, self-reported instead of measured height and weight are often used. The aim of this study is to evaluate the validity of self-reports and to identify potential predictors of the validity of body mass index (BMI) derived from self-reported height and weight. FINDINGS: Self-reported and measured data were collected from a sub-sample (3,468 adolescents aged 11-17) from the German Health Interview and Examination Survey for Children and Adolescents (KiGGS). BMI was calculated from both reported and measured values, and these were compared in descriptive analyses. Linear regression models with BMI difference (self-reported minus measured) and logistic regression models with weight status misclassifications as dependent variables were calculated.Height was overestimated by 14- to 17-year-olds. Overall, boys and girls under-reported their weight. On average, BMI values calculated from self-reports were lower than those calculated from measured values. This underestimation of BMI led to a bias in the prevalence rates of under- and overweight which was stronger in girls than in boys. Based on self-reports, the prevalence was 9.7% for underweight and 15.1% for overweight. However, according to measured data the corresponding rates were 7.5% and 17.7%, respectively. Linear regression for BMI difference showed significant differences according to measured weight status: BMI was overestimated by underweight adolescents and underestimated by overweight adolescents. When weight status was excluded from the model, body perception was statistically significant: Adolescents who regarded themselves as 'too fat' underestimated their BMI to a greater extent. Symptoms of a potential eating disorder, sexual maturation, socio-economic status (SES), school type, migration background and parental overweight showed no association with the BMI difference, but parental overweight was a consistent predictor of the misclassification of weight status defined by self-reports. CONCLUSIONS: The present findings demonstrate that the observed discrepancy between self-reported and measured height and weight leads to inaccurate estimates of the prevalence of under- and overweight when based on self-reports. The collection of body perception data and parents' height and weight is therefore recommended in addition to self-reports. Use of a correction formula seems reasonable in order to correct for differences between self-reported and measured data.

Blood pressure percentiles by age and height from nonoverweight children and adolescents in Germany.

OBJECTIVES: To present oscillometric blood pressure (BP) references from German nonoverweight children and compare them with US references. METHODS: From children and adolescents, aged 3 to 17 years, from the German Health Interview and Examination Survey for Children and Adolescents (KiGGS 2003-2006), we obtained standardized BP measurements by using an oscillometric device validated in children. Gender-specific systolic (SBP) and diastolic (DBP) BP percentiles, which simultaneously accounted for age and height by use of advanced statistical methods, were derived from nonoverweight children to avoid overweight prevalence in the reference population influencing BP references. RESULTS: The age- and gender-specific 95th percentiles from nonoverweight children (n = 12 199) were lower by up to 3 mm Hg for SBP and up to 2 mm Hg for DBP compared with the total sample (N = 14 349). KiGGS percentiles from nonoverweight children accounting simultaneously for age and height were mostly lower than in the US reference sample but higher for SBP in boys aged 14 years or older. At median height, the age-specific differences in 95th percentiles of SBP ranged from -4 to 4 mm Hg in boys and -2 to 1 mm Hg in girls and, for DBP, from -6 to 2 mm Hg in boys and -5 to 2 mm Hg in girls. CONCLUSIONS: Compared with current US references, the proposed German BP reference values are not influenced by the prevalence of overweight children in the reference population, they are based on a validated oscillometric device, and they take advantage of improved statistical methods.

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 Cole's 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.

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.