Swiss Schoolchildren Research Articles

COVID-19: Physical Activity and Quality of Life in a Sample of Swiss School Children during and after the First Stay-at-Home.

COVID-19 restrictions and the instructions to stay at home (SaH) may have had an impact on child behavior including physical activity (PA) and health-related quality of life (HRQoL) in Switzerland. Therefore, we investigated PA and HRQoL during and after the SaH in 57 Swiss school children aged 7 to 12 years (M = 10.44; SD = 1.34). PA was measured using accelerometry (Actigraph GT3X) and HRQoL using the Kid-KINDLR questionnaire. During and post data was compared using paired sample t-tests. Independent t-tests were used to compare the HRQoL of physically active children with non-physically active children. PA in light (d = −0.56), moderate (d = −0.44), moderate-to-vigorous (d = −0.28) as well as overall HRQoL (d = −0.66), psychological well-being (d = −0.48), self-esteem (d = −0.39), friends (d = −0.70) and everyday functioning (d = −0.44), were significantly lower during SaH than afterwards. Children who adhered to PA recommendations (+60 min of moderate-to-vigorous PA) during SaH had a better overall HRQoL (d = 0.61) and psychological well-being (d = 0.56) than those who did not. Since PA levels and HRQoL were lower during SaH compared to afterwards, it seems that the restrictions negatively impacted children’s PA and HRQoL. During future SaHs, promoting children’s PA and HRQoL seems important.

Prediction of Past SARS-CoV-2 Infections: A Prospective Cohort Study Among Swiss Schoolchildren.

Objective: To assess the predictive value of symptoms, sociodemographic characteristics, and SARS-CoV-2 exposure in household, school, and community setting for SARS-CoV-2 seropositivity in Swiss schoolchildren at two time points in 2020.Design: Serological testing of children in primary and secondary schools (aged 6–13 and 12–16 years, respectively) took place in June–July (T1) and October–November (T2) 2020, as part of the longitudinal, school-based study Ciao Corona in the canton of Zurich, Switzerland. Information on sociodemographic characteristics and clinical history was collected with questionnaires to parents; information on school-level SARS-CoV-2 infections was collected with questionnaires to school principals. Community-level cumulative incidence was obtained from official statistics. We used logistic regression to identify individual predictors of seropositivity and assessed the predictive performance of symptom- and exposure-based prediction models.Results: A total of 2,496 children (74 seropositive) at T1 and 2,152 children (109 seropositive) at T2 were included. Except for anosmia (odds ratio 15.4, 95% confidence interval [3.4–70.7]) and headache (2.0 [1.03–3.9]) at T2, none of the individual symptoms were significantly predictive of seropositivity at either time point. Of all the exposure variables, a reported SARS-CoV-2 case in the household was the strongest predictor for seropositivity at T1 (12.4 [5.8–26.7]) and T2 (10.8 [4.5–25.8]). At both time points, area under the receiver operating characteristic curve was greater for exposure-based (T1, 0.69; T2, 0.64) than symptom-based prediction models (T1, 0.59; T2, 0.57).Conclusions: In children, retrospective identification of past SARS-CoV-2 infections based on symptoms is imprecise. SARS-CoV-2 seropositivity is better predicted by factors of SARS-CoV-2 exposure, especially reported SARS-CoV-2 cases in the household. Predicting SARS-CoV-2 seropositivity in children in general is challenging, as few reliable predictors could be identified. For an accurate retrospective identification of SARS-CoV-2 infections in children, serological tests are likely indispensable.Trial registration number: NCT04448717.

LuftiBus in the school (LUIS): a population-based study on respiratory health in schoolchildren.

Respiratory disease is common in children and strongly associated with lifestyle and environmental exposures. Thus, it is important to study the epidemiology locally. The LuftiBus in the School (LUIS) study was set up to assess the respiratory health of schoolchildren in the canton of Zurich, Switzerland. LUIS is a cross-sectional population-based study that was carried out 2013 to 2016. Children aged 6–17 years living in the canton of Zurich were eligible to participate. All schools in the canton were approached and the school head decided whether the school would participate and with which classes. Consenting parents answered a standardised questionnaire at home and assenting children completed a shorter questionnaire by interview at school. Trained technicians measured children’s lung function, including spirometry, double tracer gas single-breath washout (DTG-SBW) and fractional exhaled nitric oxide (FeNO). Address histories of participants were geocoded to be linked with area-based socioeconomic measures and environmental exposures such as spatiotemporal air pollution estimates for specific time periods and locations. A subgroup was seen again 12 months later using the same procedures to collect longitudinal data. The study included 3870 children at baseline and 655 at the 1-year follow-up. Median age was 12.7 years; 281 (8%) had wheezed in the past year. At baseline we collected 3457 (89%) parental and 3546 (92%) child questionnaires, and 3393 (88%) FeNO, 3446 (89%) spirometry, and 1795 (46%) DTG-SBW measurements. LUIS is a rich resource of health-related data, with information on lung function, environmental exposures and respiratory health on Swiss schoolchildren.

Cigarette, shisha, and electronic smoking and respiratory symptoms in Swiss children: The LUIS study.

Smoking habits in adolescents are changing. We assessed active smoking of conventional cigarettes, e-cigarettes and shishas in Swiss schoolchildren, studied risk factors and compared respiratory problems between smokers and non-smokers. We used data from LuftiBus in the school (LUIS), a school-based survey of respiratory health of children carried out 2013 to 2016 in the canton of Zurich, Switzerland. Participants were asked about use of cigarettes, shishas, and electronic smoking devices (ESD), and current respiratory symptoms. We studied associations between smoking and risk factors using logistic regression. We included 3488 schoolchildren. Among 6 to 12-year-olds, 90/1905(5%) had smoked occasionally (<once/week). Among 13 to 17-year-olds, 563/1583(36%) had smoked occasionally of whom 414 smoked ESDs, 409 shishas, and 276 cigarettes. Among 13 to 17-year-olds who smoked frequently (≥once/week), 41/54 (76%) smoked cigarettes. A 22% of 15 to 17-year-olds (104/477) had used all three products. Smoking was more common in adolescents who were male (adjusted OR, 2.1; 95% CI, 1.7-2.6), lived in rural areas (1.8, 95% CI, 1.2-2.9 vs small urban), and whose mother (1.7, 95% CI, 1.3-2.3) or father (1.5, 95% CI, 1.2-1.9) smoked. Current respiratory symptoms like rhinitis, dyspnea, and wheeze were more common among frequent smokers (44%, 30%, 12%, respectively) and occasional smokers (32%, 22%, 13%) than in never smokers (29%,19%, 8%, P for trend <.05). Smoking of shishas and ESDs is common among Swiss adolescents and often combined with smoking cigarettes. Adolescent smokers reported more respiratory symptoms than never smokers. We recommend smoking preventive strategies that include all forms of smoking.

Sun-related knowledge and attitudes of primary and secondary schoolchildren in western Switzerland.

Switzerland, particularly its western region, has the highest incidence of melanoma in Europe. Although the risk of melanoma increases with sun overexposure during childhood, sun-related knowledge and attitudes of Swiss children are scarcely documented. We report the first investigation of the knowledge of the danger of ultraviolet radiation, attitudes towards a suntan and parental influence of schoolchildren in western Switzerland. All fifth, eighth and eleventh graders (average ages of 9, 12 and 15, respectively) in the 18 primary (fifth grade, n=431) and secondary (eighth and eleventh grades, n=837) public schools of La Chaux-de-Fonds were surveyed during regular school classes. The response rate was 91% (1154/1268). Sun-related knowledge was high overall. Eight out of 10 children knew about the risk of skin cancer and recognized the most susceptible phototype. Knowledge increased significantly with age. Girls, older children, fair-skinned participants and those who preferred a tanned skin obtained the highest knowledge score. The main source of information on ultraviolet radiation and sun protection was their parents (76%), followed by the school (11%) and the media (9%). Multivariate logistic regression analyses identified higher sun-related knowledge, lower familial socioprofessional status and skin phototypes III-IV to be associated with a tan-seeking attitude. Parental sensitization (56%) and encouragement (61%) towards sun protection were more common among fair-skinned children and those of higher familial socioprofessional status. The high awareness of the risk of skin cancer among Swiss schoolchildren does not translate into appropriate attitudes. Community-wide intervention programmes involving parents, teachers, peers and primary care clinicians could be considered for Swiss prevention campaigns to improve children's sun behaviour and change their current pro-tan attitude.

Spine day 2012: spinal pain in Swiss school children– epidemiology and risk factors

BackgroundThe key to a better understanding of the immense problem of spinal pain seems to be to investigate its development in adolescents. Based on the data of Spine Day 2012 (an annual action day where Swiss school children were examined by chiropractors on a voluntary basis for back problems), the aim of the present study was to gain systematic epidemiologic data on adolescent spinal pain in Switzerland and to explore risk factors per gender and per spinal area.MethodData (questionnaires and physical examinations) of 836 school children were descriptively analyzed for prevalence, recurrence and severity of spinal pain. Of those, 434 data sets were included in risk factor analysis. Using logistic regression analysis, psycho-social parameters (presence of parental back pain, parental smoking, media consumption, type of school bag) and physical parameters (trunk symmetry, posture, mobility, coordination, BMI) were analyzed per gender and per spinal area.ResultsPrevalence of spinal pain was higher for female gender in all areas apart from the neck. With age, a steep increase in prevalence was observed for low back pain (LBP) and for multiple pain sites. The increasing impact of spinal pain on quality of life with age was reflected in an increase in recurrence, but not in severity of spinal pain. Besides age and gender, parental back pain (Odds ratio (OR)=3.26, p=0.011) and trunk asymmetry (OR=3.36, p=0.027) emerged as risk factors for spinal pain in girls. Parental smoking seemed to increase the risk for both genders (boys: OR=2.39, p=0.020; girls: OR=2.19, p=0.051). Risk factor analysis per spinal area resulted in trunk asymmetry as risk factor for LBP (OR=3.15, p=0.015), while parental smoking increased the risk for thoracic spinal pain (TSP) (OR=2.83, p=0.036) and neck pain (OR=2.23, p=0.038). The risk for TSP was further enhanced by a higher BMI (OR=1.15, p=0.027).ConclusionThis study supports the view of adolescent spinal pain as a bio-psycho-social problem that should be investigated per spinal area, age and gender. The role of trunk asymmetry and passive smoking as risk factors as well as the association between BMI and TSP should be further investigated, preferably in prospective studies.

The Swiss Iodized Salt Program Provides Adequate Iodine for School Children and Pregnant Women, but Weaning Infants Not Receiving Iodine-Containing Complementary Foods as well as Their Mothers Are Iodine Deficient

If children and pregnant women in the population are iodine sufficient, it is generally assumed infants are also sufficient. But weaning infants may be at risk of iodine deficiency because iodized salt contributes little dietary iodine during this period. To fill this gap, iodine fortification of infant formula milk (IFM) and complementary foods (CF) is likely important. The objective of the study was to first confirm that Swiss school children and pregnant women remain iodine sufficient and then to assess iodine status in infancy and the relative contribution of breast milk and IFM/CF to their iodine intakes. We measured urinary iodine concentrations (UIC) in national cross-sectional samples of: 1) pregnant women (n=648); 2) school children (n=916); 3) infants at three time points: at 3-4 d after birth and at 6 and 12 months (n=875); and 4) breast-feeding mothers (n=507). We measured breast milk iodine concentrations in the mothers, assessed iodine sources in infant diets, and analyzed iodine content of commercial IFM/CFs (n=22) and salt samples from the school children's households (n=266). Median (m) UICs in pregnant women (162 μg/liter) and school children (120 μg/liter) were sufficient, and 80% of the household salt was adequately iodized (≥15 ppm). However, mUICs in infants not receiving IFM/CF were not sufficient: 1) mUIC in breast-fed infants (82 μg/liter) was lower than in non-breast-fed infants (105 μg/liter) (P<0.001) and 2) mUIC in breast-fed weaning infants not receiving IFM/CF (70 μg/liter) was lower than infants receiving IFM (109 μg/liter) (P<0.01). mUIC was low in lactating mothers (67 μg/liter) and median breast milk iodine concentration was 49 μg/kg. In countries in which iodized salt programs supply sufficient iodine to older children and pregnant women, weaning infants, particularly those not receiving iodine-containing IFM, may be at risk of inadequate iodine intakes.

Stabilization of the prevalence of childhood obesity in Switzerland

The prevalence of childhood obesity is increasing rapidly in most industrialised countries, but several countries, including Switzerland, have recently reported a levelling off or even a reversal of this alarming trend. Our aim was to evaluate the prevalence of childhood obesity in a national sample of Swiss school children recruited to assess iodine nutrition and with this to reconfirm a recently shown stabilising trend. Using a probability-proportionate-to-size cluster sampling, 6 to 12 year old children (n = 907) were recruited in a study of iodine status in Switzerland. Height and weight were measured and body mass index calculated in all children. The prevalence of overweight detected was 12.5% (SE = 1.6) in boys and 12.8% (1.6) in girls while 6.2% (1.1) of boys and 4.2% (0.9) of girls were classified as obese. The highest prevalence of overweight and obesity were found in the Southern region and in bigger cities (>100000 inhabitants). Compared to the most recent national study in 2007, the prevalence was slightly higher, but the differences were not significant, suggesting negative sampling bias does not strongly affect surveys of paediatric adiposity in Switzerland. This present study clearly confirms the stabilisation of the prevalence of childhood overweight and obesity in Switzerland.

Trend in active transportation to school among Swiss school children and its associated factors: three cross-sectional surveys 1994, 2000 and 2005

BackgroundGiving the rising trend in childhood obesity in many countries including Switzerland, strategies to increase physical activity such as promoting active school travel are important. Yet, little is known about time trends of active commuting in Swiss schoolchildren and factors associated with changes in walking and biking to school.MethodsBetween 1994 and 2005, information about mobility behaviour of children aged 6-14 years was collected within three Swiss population based national travel behaviour surveys. Mode of transport to school was reported for 4244 children. Weighted multivariate logistic regression analyses were used to assess active school travel time trends and their influencing factors.ResultsMore than 70% of Swiss children walked or biked to school. Nevertheless, the proportion of children biking to school decreased (p = 0.05, linear trend), predominately in urban areas, and motorized transportation increased since 1994 (p = 0.02). Distance to school did not change significantly over time but availability of bikes decreased (p < 0.001) and number of cars per household increased (p < 0.001). The association between survey year and bike use was significantly modified by living in an urban area (OR (95%CI): 1.0, 0.63 (0.44-0.90), 0.71 (0.49-1.03), respectively for 1994, 2000 and 2005) and by distance to school (OR (95%CI): 1.0, 0.65 (0.40-1.05), 0.50 (0.23-0.79) for the same years and for children who lived more than a mile away from school).ConclusionsPrograms to encourage safe biking and to limit car use as mode of transport to school are warranted to stop this trend.

Assessment of intensity, prevalence and duration of everyday activities in Swiss school children: a cross-sectional analysis of accelerometer and diary data

BackgroundAppropriately measuring habitual physical activity (PA) in children is a major challenge. Questionnaires and accelerometers are the most widely used instruments but both have well-known limitations. The aims of this study were to determine activity type/mode and to quantify intensity and duration of children's everyday PA by combining information of a time activity diary with accelerometer measurements and to assess differences by gender and age.MethodsSchool children (n = 189) aged 6/7 years, 9/10 years and 13/14 years wore accelerometers during one week in winter 2004 and one in summer 2005. Simultaneously, they completed a newly developed time-activity diary during 4 days per week recording different activities performed during each 15 min interval. For each specific activity, the mean intensity (accelerometer counts/min), mean duration per day (min/d) and proportion of involved children were calculated using linear regression models.ResultsFor the full range of activities, boys accumulated more mean counts/min than girls. Adolescents spent more time in high intensity sports activities than younger children (p < 0.001) but this increase was compensated by a reduction in time spent playing vigorously (p = 0.04). In addition, adolescents spent significantly more time in sedentary activities (p < 0.001) and accumulated less counts/min during these activities than younger children (p = 0.007). Among moderate to vigorous activities, children spent most time with vigorous play (43 min/day) and active transportation (56 min/day).ConclusionThe combination of accelerometers and time activity diaries provides insight into age and gender related differences in PA. This information is warranted to efficiently guide and evaluate PA promotion.

Physical Activity Level of Swiss School Children in Comparison to other European Children

Only little is known about the activity pattern of Swiss school children. PURPOSE: The objective of this study was to (a) determine the extent, intensity and pattern of PA in Swiss school children and (b) to compare it with children (age 9.6±0.4yrs) of 4 distinct regions in Europe. METHODS: 357 children (166 boys, age 9.5±2.1yrs and 191 girls, age 9.3±2.1yrs) were randomly selected and stratified by age, geographic region, and by ethnicity. Subjects wore an accelerometer (MTI Actigraph) slightly superior to the right iliac crest for 7 consecutive days. Total PA (total counts/daily hours awake) and vigorous activity (>3000cpm) were calculated over 2 weekdays and 2 weekend days in order to be able to compare PA of Swiss children with PA from children of other European countries. RESULTS: Swiss boys were significantly more active than Swiss girls (788±209 vs. 673±165cpm, p<.01). Total PA of Swiss children was significantly higher on weekdays than on weekends (781±212 vs. 670±241cpm, p<.01). 27.0% of Portuguese children, 14.3% of Swiss children, 13.4% of Norwegian children, 12.0% of Danish children, and 9.8% of Estonian children were classified as overweight or obese. Swiss children (boys: 788±209; girls: 673±165cpm) were more active than Estonian (boys: 778±277; girls: 661±202cpm), Danish (boys: 749±290; girls: 603±213cpm) and Portuguese children (boys: 747±238; girls: 615±158cpm), however less than Norwegian children (boys: 870±307; girls: 741±204cpm). The fraction of time spent at vigorous PA was higher in Swiss children (boys: 6.2±2.8; girls: 4.1±2.0%) than in Estonian (boys: 5.8±3.7; girls: 3.9±2.5%), Portuguese (boys: 5.6±3.5; girls: 3.6±2.2%) and Danish children (boys: 5.3±3.3; girls: 3.2±2.5%), however less than in Norwegian children (boys: 7.4±3.6; girls: 5.4±2.5%). CONCLUSION: Children across Europe seem to have different activity levels depending on sex and country of origin. In general, boys are more active than girls. Furthermore, Norwegian children are the most active followed by Swiss, Estonian, Danish and Portuguese children. This could explain why the best performing children in the Eurofittest come from northern and central European countries. Supported by the Federal council of Sports, Magglingen, Switzerland

Factors Associated with Obesity and Cardiovascular Risk in Swiss Schoolchildren [ISRCTN15360785

Given the dramatic increase in childhood obesity over the last decades, we wanted to assess the relationship between childhood obesity and multiple risk factors in a representative population of schoolchildren. METHODS: 535 children in 1 st and 5th grade (6–13y) from randomly selected socio-ethnic diverse public schools in Switzerland were investigated. Assessment included questionnaires, anthropometry, accelerometry, fitness testing and in 68% of children fasting blood samples (insulin, glucose, highly sensitive C-reactive protein (hs-CRP)). The independent association of fitness and insulin resistance (HOMA-IR) or low-grade chronic inflammation (hs-CRP) was assessed using partial correlation analyses. The association between overweight and obesity (BMI percentiles), cardiopulmonary fitness (20m shuttle run), physical activity (accelerometers, counts/day), television (TV) use, daily sleep length, nutritional habits (food frequency questionnaires), parental BMI and educational level, birth weight, age, sex and Tanner stages was assessed using multiple logistic regression. RESULTS: The prevalence of overweight and obesity was 15% and 11%, respectively. Sweetened carbonated drinks were consumed 2.4 ± 2.1 times/wk. 20% of children ate fast foods more than 5 times/wk, but only 23% went to a fast food restaurant more than once a month. They watched TV for 85±102 min/d. Even after controlling for age, sex, pubertal stage and BMI, increased hs-CRP and HOMA-IR were negatively correlated with fitness (r= −0.22, p<0.0001 andr= −0.12, p<0.05). In multiple logistic regression analyses, being obese or overweight was positively associated with maternal overweight and TV time and negatively with fitness and physical activity (p<0.0001, n=284), but not with nutritional habits. CONCLUSION: In Swiss children decreased fitness is associated with novel and traditional cardiovascular risk factors independent of BMI. Overweight and obesity are mainly associated with decreased fitness and physical activity, and with maternal overweight and increased TV use. Thus, preventive strategies to increase physical activity and fitness and to decrease inactivity and overweight are of utmost importance to improve the health of children.

Influence of MMR-vaccinations and diseases on atopic sensitization and allergic symptoms in Swiss schoolchildren.

The prevalence of asthma and allergic disease has increased in many countries. It has been proposed that vaccinations may contribute to the development of allergic disease by reducing clinical infections in infancy or through the direct IgE-inducing effects of the vaccines. Evidence for a potential role of immunizations in the development of allergic disease is scarce. Therefore the objective was to study the associations between vaccinations against measles, mumps and rubella (MMR), natural infections of these diseases and atopic sensitization to indoor and outdoor allergens and allergic symptoms in schoolchildren. The cross-sectional study including 1537 8(th) grade school children aged 13-15 years living in 10 communities across Switzerland was organized in the framework of an environmental health surveillance program within the School Health Services (Swiss Surveillance Program of Childhood Asthma and Allergies with respect to Air Pollution and Climate, SCARPOL). Main outcome measures were asthma and sneezing during pollen season assessed by parental questionnaires and atopic sensitization determined by IgE concentrations to various allergens. It was found that parents' reported history of measles or mumps was associated with a stronger immune response than two or more vaccinations against the respective infection (measles: geometric mean IgG titers (GMT) lU/ml (95% Cl) 2.8 (2.0-3.9) vs. 1.2 (1.0-1.4), mumps: GMT PE/ml (95% Cl) 16.3 (13.9-19.1) vs. 8.5 (6.1-11.7). With respect to atopic sensitization similar associations for exposure by natural MMR-infections or MMR-vaccinations were found: measles: OR (95% Cl) 1.02 (0.53-1.96) vs. 1.22 (0.69-2.16), mumps: 0.59 (0.38-0.93) vs. 0.79 (0.49-1.27), rubella: 0.93 (0.61-1.43) vs. 0.95 (0.66-1.37), respectively. Inverse relationships were found between the risk of asthma and a positive disease history or vaccination of measles 0.36 (0.14-0.91) vs. 0.45 (0.21-0.98) or a positive serum titer against measles 0.65 (0.35-1.20). From the present study can be concluded that exposure by MMR-vaccinations or natural MMR-infections in childhood does not increase the risk of sensitization to common allergens as well as to allergic respiratory diseases. MMR-vaccinations or natural MMR-infections are therefore an unlikely factor contributing to the increase in atopic disease in developed countries.

Monitoring the adequacy of salt iodization in Switzerland: a national study of school children and pregnant women

Several countries with long-standing salt iodization programs, including Switzerland, have recently reported declining and/or low urinary iodine (UI) levels in their populations. In Switzerland, in response to studies indicating low UI levels in children and pregnant women, the salt iodine level was increased in 1998 from 15 to 20 mg/kg. Our objective was to evaluate iodine nutrition in a national sample of Swiss school children and pregnant women 8 16 months after the increase in the salt iodine level. A 3-stage probability proportionate to size cluster sampling method was used to obtain a representative national sample of 600 children aged 6-12 y and 600 pregnant women. We then measured UI in both groups, thyrotropin (TSH) in pregnant women and thyroid volume by ultrasound to determine goiter prevalence in school children. The median UI (range) of the children and pregnant women was 115 microg/l (5-413) and 138 microg/l (5-1881), respectively. The median blood TSH concentration (range) of pregnant women was 0.6 mU/l (0.2-2.1). Based on the current WHO/ICCIDD normative data for thyroid volume, none of the children were goitrous, using either age/sex-specific or BSA/sex-specific cutoffs. The iodine status of the Swiss population is once again adequate, illustrating the value of periodic monitoring and prudent adjustments to the iodine level in salt. This approach could serve as a model for countries struggling to maintain dietary iodine intake in the face of shifting dietary habits and changes in the food supply.

Thyroid volumes and urinary iodine in Swiss school children, 17 years after improved prophylaxis of iodine deficiency.

Salt iodine content in Switzerland was raised from 7.5 to 15 mg per kg in 1980, and since then dietary iodine intake has been considered to be sufficient, even though a slight decrease due to imported food has recently been reported. The aim of this study was to establish normal values for thyroid volumes of school children who can be assumed to have had a sufficient iodine intake all their lifetime. Moreover. the present investigation was undertaken to verify that iodine sufficiency had been achieved equally in two regions each served by one of the two Swiss salt producers. Mean iodine concentration in urine spot samples from school children was 16.1 microg/dl, and it was identical in both the city of Lausanne (n=215) and the city of Solothurn (n=208). Thus it can be stated that in both cities (served by two different salt producers) iodine intake is equal and sufficient. Accordingly, thyroid volumes measured by ultrasound in school children aged 6 to 16 years were the same in both Lausanne (n=202) and Solothurn (n=207). Moreover, the age-adjusted median volumes at the 97th percentiles closely agree with and validate provisional international reference values recently proposed by the World Health Organisation and by the International Council for Control of Iodine Deficiency Disease.

Validation of a rhinitis symptom questionnaire (ISAAC core questions) in a population of Swiss school children visiting the school health services. SCARPOL-team. Swiss Study on Childhood Allergy and Respiratory Symptom with respect to Air Pollution and Climate. International Study of Asthma and Allergies in Childhood.

The primary aim of the study was to assess the validity of the ISAAC core questions on rhinitis in a population of Swiss school children by comparing them to skin prick test results. Second, the positive predictive value in detecting atopy among children with rhinitis symptoms was determined. Third, agreement between parental reports of hay fever and rhinitis symptoms was evaluated, since earlier Swiss prevalence surveys had exclusively relied on reported hay fever. Two thousand nine hundred and fifty-four (81.2%) parents of 7, 10 and 14-year old children filled in an exhaustive questionnaire which included the ISAAC core questions on rhinitis. Two thousand one hundred and twenty children also underwent skin prick testing against six common aeroallergens (grass mixture, birch, mugwort, D. pteronyssinus, cat and dog dander). The analysis is restricted to children with both questionnaire data and skin prick test results. Sensitization to any allergen was most strongly associated with reported hay fever (OR = 5.7, 95% CI 4.4-7.4), nose problems accompanied by itchy-watery eyes (OR = 4.4, 95% CI: 3.3-5.7), symptoms occurring only during pollen season (March through September) (OR = 4.9, 95% CI: 3.6-6.5) and a combination of these latter two symptoms (OR = 5.8, 95% CI: 4.1-8.1). The association was stronger for a sensitization to outdoor allergens than for indoor allergens. The specificity of the various questions was high, ranging from 77.5% to 97.6%, but the sensitivity was low (2.6% to 42.7%). The positive predictive value for atopy among children with symptoms was 63% for sneezing accompanied by itchy-watery eyes, 67% for symptoms occurring only during the pollen season and 70% for reported hay fever. However, agreement between reported rhinitis symptoms and hay fever was only moderate. About one third of the children with symptoms indicative of seasonal rhinitis did not report the label "hay fever". We conclude from our analyses that the ISAAC core questions on rhinitis are highly specific and therefore useful in excluding atopy. In addition they have a high positive predictive value in detecting atopy among children with symptoms, but they are not helpful for detecting atopy in a general population of children (low sensitivity). To monitor time trends in the prevalence of allergic rhinitis in Switzerland, questions on rhinitis symptoms as well as on the diagnostic label "hay fever" have to be included in a questionnaire because they contain complementary information since under-diagnosis of allergic rhinitis is common.

Respiratory health and long-term exposure to air pollutants in Swiss schoolchildren. SCARPOL Team. Swiss Study on Childhood Allergy and Respiratory Symptoms with Respect to Air Pollution, Climate and Pollen.

The impact of long-term exposure to air pollution on respiratory and allergic symptoms and illnesses was assessed in a cross-sectional study of schoolchildren (ages 6 to 15 yr, n = 4,470) living in 10 different communities in Switzerland. Air pollution measurements (particulate matter less than 10 microns in diameter [PM10], nitrogen dioxide [NO2], sulfur dioxide [SO2], and ozone) and meteorologic data were collected in each community. Reported symptom rates of chronic cough, nocturnal dry cough, and bronchitis, adjusted for individual risk factors, were positively associated with PM10, NO2, and SO2. The strongest relationship was observed for PM10 (adjusted odds ratios for chronic cough, nocturnal dry cough, and bronchitis between the most and the least polluted community for PM10 were 3.07 [95% CI: 1.62 to 5.81], 2.88 [95% CI: 1.69 to 4.89], and 2.17 [95% CI: 1.21 to 4.89], respectively). The high correlation between the average concentrations of the pollutants makes the assessment of the relative importance of each pollutant difficult. No association between long-term exposure to air pollution and classic asthmatic and allergic symptoms and illnesses was found. There was some indication that frequency of fog is a risk factor of chronic cough and bronchitis, independent of air pollution. In conclusion, this study provides further evidence that rates of respiratory illnesses and symptoms among children augment with increasing levels of air pollution even in countries like Switzerland with moderate average air pollution concentrations.

Prevalence of respiratory symptoms in Swiss children: Is bronchial asthma really more prevalent in boys?

Precise epidemiological data for the prevalence of childhood asthma were lacking for Switzerland until recently. In 1990 we performed a stratified cluster sampling of schoolchildren (aged 7, 12, and 15 years), using a parent completed questionnaire to obtain data for the 12 months prevalence of asthma symptoms and the lifetime prevalence of asthma diagnosis. A response rate of 97.5% enabled us to analyse 4,353 completed questionnaires. The prevalence of any asthma symptom during the last 12 months was 17.5% while only 4.8% of the children reported the diagnostic label "asthma". The 12 months prevalence of chronic night cough was 12% and is comparable to other European data. Wheeze (5.9%) was reported less often in Switzerland than in England. At the age of 7 years asthma symptoms such as wheeze, morning tightness, and allergen-induced symptoms were reported more often in boys than in girls; at the age of 12 and 15 the male preponderance was no more evident. For all asthma symptoms the male-female ratio decreased with increasing age of the children, while independently of age twice as many boys than girls reported the diagnostic label "asthma." We conclude that asthma symptom prevalence in Swiss schoolchildren is within the lower range of European data. Chronic night cough might be a more appropriate variable to compare prevalence rates between regions with different cultural and linguistic backgrounds that the symptom of wheeze. Evidence exists for a substantial underdiagnosis of bronchial asthma in Swiss children, especially in girls. Further evaluation is needed to define risk factors for underdiagnosis and the associated risk for undertreatment.

NET AVERAGE YEARLY CHANGES IN REFRACTION OF ATROPINIZED EYES FROM BIRTH TO BEYOND MIDDLE LIFE

Most studies of the changes in the refraction of the eye lack both accuracy and mass of observation. There are two notable exceptions. Steiger 1 in 1913 studied hundreds of Swiss school children between 6 and 11 years of age and developed therefrom his biologic theory of inheritance of states of refraction and the changes which take place in the eyes of growing children. The refraction was determined by the manifest method, without cycloplegia, and his conclusions are open to criticism on this score. The second study was made by Kempf, Jarman and Collins 2 for the United States Public Health Service in 1928 on the homatropinized eyes of 1,860 school children, and the results should therefore be more accurate than those of Steiger. A more recent study of the problems connected with defective vision in school children was made on the homatropinized eyes of 2,625 children by twenty-two observers