Motor and visuomotor function in 10-year-old children with congenital heart disease: association with behaviour.

BACKGROUND: Children with CHD are at increased risk for neurodevelopmental impairments. There is little information on long-term motor function and its association with behaviour. AIMS: To assess motor function and behaviour in a cohort of 10-year-old children with CHD after cardiopulmonary bypass surgery. METHODS: Motor performance and movement quality were examined in 129 children with CHD using the Zurich Neuromotor Assessment providing four timed and one qualitative component, and a total timed motor score was created based on the four timed components. The Beery Test of Visual-Motor Integration and the Strengths and Difficulties Questionnaire were administered. RESULTS: All Zurich Neuromotor Assessment motor tasks were below normative values (all p ≤ 0.001), and the prevalence of poor motor performance (≤10th percentile) ranged from 22.2% to 61.3% in the different components. Visuomotor integration and motor coordination were poorer compared to norms (all p ≤ 0.001). 14% of all analysed children had motor therapy at the age of 10 years. Children with a total motor score ≤10th percentile showed more internalising (p = 0.002) and externalising (p = 0.028) behavioural problems. CONCLUSIONS: School-aged children with CHD show impairments in a variety of motor domains which are related to behavioural problems. Our findings emphasise that motor problems can persist into school-age and require detailed assessment and support.

Integration of Speed and Quality in Measuring Graphomotor Skills: The Zurich Graphomotor Test.

IMPORTANCE: In educational settings, children are under pressure to finish their work successfully within required time frames. Existing tools for assessing graphomotor skills measure either quality or speed of performance, and the speed-accuracy trade-off (SAT) in such tools has never been investigated. OBJECTIVE: We aimed to evaluate a newly developed tool for measuring graphomotor skills, the Zurich Graphomotor Test (ZGT), that assesses both speed and quality of performance. We also explored whether graphomotor tests are affected by the SAT and, if so, the effects it has on graphomotor test results. DESIGN: Cross-sectional study. SETTING: Educational institutions in Switzerland. PARTICIPANTS: Children, adolescents, and young adults (N = 547) ages 4-22 yr (50.3% female). OUTCOMES AND MEASURES: Graphomotor performance was measured with the ZGT and the Developmental Test of Visual Perception, Second Edition (DVTP-2). Standard deviation scores were used to quantify performance. We combined ZGT speed and quality measurements into a performance score adjusted for age and sex. RESULTS: ZGT results indicated a marked developmental trend in graphomotor performance; older children were faster than younger children. Girls showed higher overall performance than boys. The pattern of making more mistakes when being faster and making fewer mistakes when being slower was observed for both graphomotor tests, regardless of time pressure, indicating that the SAT affected the children's scores on both tests. CONCLUSIONS AND RELEVANCE: SAT is influential in graphomotor assessment. The ZGT captures this trade-off by combining accuracy and speed measurements into one score that provides a realistic assessment of graphomotor skills. What This Article Adds: The newly developed ZGT provides occupational therapy practitioners with more precise information on graphomotor skills in children, adolescents, and young adults than currently available tools.

Impact of body mass index and socio-economic status on motor development in children and adolescents.

This study assessed the impact of body mass index (BMI) and socioeconomic status (SES) on the Zurich Neuromotor Assessment, second version (ZNA-2), a battery of tests of motor development in typically developing children between 3 and 18 years of age. BMI measurements and international socio-economic index data were taken from the normative sample of the ZNA-2 for 321 children (158 boys, 163 girls) with a median age of 9.3 years. The age- and gender-adjusted motor performance of these children was quantified and grouped into five components: fine, pure, and gross motor tasks, static balance, and contralateral associated movements. A total score was also calculated. The associations of BMI and SES with the motor scores contribute to less than 5.1% of the total variance.Conclusion: The ZNA-2 for motor development is suitable for measuring motor abilities' development as it is largely independent of the BMI of the child and the SES of the family. What is Known: • Typical motor development, as measured with the Zurich Neuromotor Assessment, second edition (ZNA-2), is strongly dependent on age and gender. • The ZNA-2 focusses on motor performance, motor quality and simple motor skills. What is New: • Higher socio-economic status (SES) is associated with slightly better motor performance as measured by the ZNA-2 total score. • In the ZNA-2 less than 5.1% of the variability in motor performance is attributable to the combined effect of body mass index and SES.

A quick and qualitative assessment of gross motor development in preschool children.

There is a need for a quick, qualitative, reliable, and easy tool to assess gross motor development for practitioners. The aim of this cross-sectional study is to present the Zurich Neuromotor Assessment-Q (ZNA-Q), which assesses static and dynamic balance in children between 3 and 6 years of age in less than 5 min. A total of 216 children (103 boys; 113 girls; median age 4 years, 4 months; interquartile range 1 year, 3 months) were enrolled from day-care centers, kindergartens, and schools, and were tested with 5 different gross motor tasks: standing on one leg, tandem stance, hopping on one leg, walking on a straight line, and jumping sideways. All ordinal measures (consisting of qualitative measures and scales) featured a marked developmental trend and substantial inter-individual variability. Test-retest reliability was assessed on 37 children. It varied from .17 for tandem stance to .43 for jumping sideways for the individual tasks, and it was .41 and .67 for the static and dynamic balance components, respectively. For the whole ZNA-Q, test-retest reliability was .7.Conclusion: Ordinal scales enable practitioners to gather data on children's gross motor development in a fast and uncomplicated way. It offers the practitioner with an instrument for the exploration of the current developmental motor status of the child. What is Known: • Measurement of gross motor skills in the transitional period between motor mile stones and quantitative assessments is difficult. • Assessment of gross motor skills is relatively easy. What is New: • Supplementary and quick gross motor test battery for children for practitioners. • Normative values of five gross motor skills measured with ordinal scales.

Neuromotor development in children. Part 4: new norms from 3 to 18 years.

AIM: The aim of this cross-sectional study was to provide normative data for motor proficiency (motor performance and contralateral associated movements [CAMs]) in typically developing children between 3 years and 18 years of age using an updated version of the Zurich Neuromotor Assessment (ZNA-2). METHOD: Six-hundred and sixteen typically developing children between 3 years and 18 years of age were enrolled from day-care centres, kindergartens, and schools, and were tested using the ZNA-2 with improved items of the original battery. Motor proficiency was assessed on five components (fine motor tasks, pure motor tasks, static balance, dynamic balance, and CAMs) as a function of age and sex to determine centile curves for each task. Intraobserver, interobserver, and test-retest reliabilities were evaluated. RESULTS: Most ZNA-2 tasks featured a marked developmental trend and substantial interindividual variability. Test-retest reliability was generally high (e.g. static balance 0.67; CAMs 0.81; and total scores 0.84). INTERPRETATION: The ZNA-2 is a reliable and updated test instrument to measure motor proficiency in children from 3 to 18 years with improved properties for assessing motor performance. It allows continuous measurement without changing items for the entire age range; this feature of the ZNA-2 is unique and makes the instrument suitable for clinical purposes. The reduction of CAMs scoring simplifies the clinical procedure and increases its reliability. WHAT THIS PAPER ADDS: The Zurich Neuromotor Assessment, Second Edition (ZNA-2) provides new norms for motor proficiency in children between 3 years and 18 years. High reliabilities suggest that the revised test battery is a useful tool for assessing neuromotor development. Integration of a 'not able to perform' category makes the ZNA-2 suitable for clinical purposes.

Stability of cognitive performance in children with mild intellectual disability.

AIM: Longitudinal studies that have examined cognitive performance in children with intellectual disability more than twice over the course of their development are scarce. We assessed population and individual stability of cognitive performance in a clinical sample of children with borderline to mild non-syndromic intellectual disability. METHOD: Thirty-six children (28 males, eight females; age range 3-19y) with borderline to mild intellectual disability (Full-scale IQ [FSIQ] 50-85) of unknown origin were examined in a retrospective clinical case series using linear mixed models including at least three assessments with standardized intelligence tests. RESULTS: Average cognitive performance remained remarkably stable over time (high population stability, drop of only 0.38 IQ points per year, standard error=0.39, p=0.325) whereas individual stability was at best moderate (intraclass correlation of 0.58), indicating that about 60% of the residual variation in FSIQ scores can be attributed to between-child variability. Neither sex nor socio-economic status had a statistically significant impact on FSIQ. INTERPRETATION: Although intellectual disability during childhood is a relatively stable phenomenon, individual stability of IQ is only moderate, likely to be caused by test-to-test reliability (e.g. level of child's cooperation, motivation, and attention). Therefore, clinical decisions and predictions should not rely on single IQ assessments, but should also consider adaptive functioning and previous developmental history.

Secular trends in physical growth, biological maturation, and intelligence in children and adolescents born between 1978 and 1993.

Introduction: Human physical growth, biological maturation, and intelligence have been documented as increasing for over 100 years. Comparing the timing of secular trends in these characteristics could provide insight into what underlies them. However, they have not been examined in parallel in the same cohort during different developmental phases. Thus, the aim of this study was to examine secular trends in body height, weight, and head circumference, biological maturation, and intelligence by assessing these traits concurrently at four points during development: the ages of 4, 9, 14, and 18 years. Methods: Data derived from growth measures, bone age as an indicator of biological maturation, and full-scale intelligence tests were drawn from 236 participants of the Zurich Longitudinal Studies born between 1978 and 1993. In addition, birth weight was analyzed as an indicator of prenatal conditions. Results: Secular trends for height and weight at 4 years were positive (0.35 SD increase per decade for height and an insignificant 0.27 SD increase per decade for weight) and remained similar at 9 and 14 years (height: 0.46 SD and 0.38 SD increase per decade; weight: 0.51 SD and 0.51 SD increase per decade, respectively) as well as for weight at age 18 years (0.36 SD increase per decade). In contrast, the secular trend in height was no longer evident at age 18 years (0.09 SD increase per decade). Secular trends for biological maturation at 14 years were similar to those of height and weight (0.54 SD increase per decade). At 18 years, the trend was non-significant (0.38 SD increase per decade). For intelligence, a positive secular trend was found at 4 years (0.54 SD increase per decade). In contrast, negative secular trends were observed at 9 years (0.54 SD decrease per decade) and 14 years (0.60 SD decrease per decade). No secular trend was observed at any of the four ages for head circumference (0.01, 0.24, 0.17, and - 0.04 SD increase per decade, respectively) and birth weight (0.01 SD decrease per decade). Discussion: The different patterns of changes in physical growth, biological maturation, and intelligence between 1978 and 1993 indicate that distinct mechanisms underlie these secular trends.

Long-term neurodevelopmental outcome with hypoxic-ischemic encephalopathy.

OBJECTIVES: To determine the long-term neurodevelopmental outcome for children after hypoxic-ischemic encephalopathy (HIE) without major disability, and to examine neonatal injury patterns detected on cerebral magnetic resonance imaging (MRI) in relation to later deficits. STUDY DESIGN: Prospectively enrolled children with HIE and neonatal cerebral MRI data (n = 68) were examined at a mean age of 11.2 years (range, 8.2-15.7 years). Eleven children had a major disability (ie, cerebral palsy or mental retardation). Brain injury was scored according to the region and extent of injury. RESULTS: Children without major disability (n = 57) had lower full-scale and performance IQ scores compared with norms (P = .02 and .01, respectively), and the proportion of children with an IQ <85 was higher than expected (P = .04). Motor performance on the Zurich Neuromotor Assessment was affected in the pure motor, adaptive fine motor, and gross motor domains, as well as in the movement quality domain (all P < .001). Watershed injury pattern on neonatal MRI correlated with full-scale and verbal IQ scores (P = .006 and <.001, respectively), but neonatal MRI pattern did not correlate with motor performance in children without major disability. CONCLUSION: Children who sustained neonatal HIE without major disability are at increased risk for long-term intellectual, verbal, and motor deficits. The severity of watershed injury is correlated with later intellectual performance. Long-term follow-up examinations are necessary for early detection of neurodevelopmental impairment and early initiation of adequate therapies.

Neuromotor development in children. Part 3: motor performance in 3- to 5-year-olds.

AIM: The aim of this cross-sectional study was to provide normative data (ordinal scores and timed performances) for gross and fine motor tasks in typically developing children between 3 and 5 years of age using the Zurich Neuromotor Assessment (ZNA). METHOD: Typically developing children (n=101; 48 males, 53 females) between 3 and 5 years of age were enrolled from day-care centres in the greater Zurich area and tested using a modified version of the ZNA; the tests were recorded digitally on video. Intraobserver reliability was assessed on the videos of 20 children by one examiner. Interobserver reliability was assessed by two examiners. Test-retest reliability was performed on an additional 20 children. The modelling approach summarized the data with a linear age effect and an additive term for sex, while incorporating informative missing data in the normative values. Normative data for adaptive motor tasks, pure motor tasks, and static and dynamic balance were calculated with centile curves (for timed performance) and expected ordinal scores (for ordinal scales). RESULTS: Interobserver, intraobserver, and test-retest reliability of tasks were moderate to good. Nearly all tasks showed significant age effects, whereas sex was significant only for stringing beads and hopping on one leg. INTERPRETATION: These results indicate that timed performance and ordinal scales of neuromotor tasks can be reliably measured in preschool children and are characterized by developmental change and high interindividual variability.

Neurodevelopmental outcome, psychological adjustment, and quality of life in adolescents with congenital heart disease.

AIM: The aim of this study was to examine neurodevelopment, psychological adjustment, and health-related quality of life (HRQoL) in adolescents after bypass surgery for congenital heart disease (CHD) during early childhood. METHOD: Fifty-nine adolescents (34 females, 25 males) with CHD were examined at a median age of 13 years 8 months (range 11 y 5 mo-16 y 11 mo). Outcome was assessed with the Wechsler Intelligence Scale for Children, (fourth edition); the Beery Test of Visual-Motor Integration; the Rey-Osterrieth Complex Figure Test; the Zurich Neuromotor Assessment; the Strengths and Difficulties Questionnaire; and the KIDSCREEN questionnaires. Results were compared with those of 40 age- and sex-matched healthy comparison individuals. RESULTS: Outcome with regard to full-scale IQ, perceptual reasoning, and the working memory scale was poorer in patients with CHD than in the comparison group (all p ≤ 0.001). Visual perception, visuomotor integration (p ≤ 0.001), and executive functions (Rey figure copy: p=0.05) were also affected. Patients with CHD also had lower scores on all motor domains (p < 0.02) except static balance. Psychological adjustment was affected only in the 'peer relationship' domain (p=0.05). Quality of life was similar to that of typically developing peers. INTERPRETATION: Adolescents with CHD may manifest persistent cognitive and motor impairments, while psychological adjustment and self-reported HRQoL are mostly typical. Thus, long-term neurodevelopmental evaluations are necessary to provide early educational and therapeutic support.

Development of neuromotor functions in very low birth weight children from six to 10 years of age: patterns of change.

AIM: To assess patterns of change for different neuromotor functions in very low birth weight (VLBW) children during school age and to identify factors associated with improvement. METHODS: In a longitudinal study, we examined 65 prospectively enrolled VLBW children (38 female, 59%) without cerebral palsy at age six and 10 years. Measures included the evaluation of timed motor performance and motor overflow (MO) for the motor components of the Zurich Neuromotor Assessment (pure motor-, adaptive fine- and gross motor tasks, static balance) and a standardized neurological examination. Variables associated with improvement were assessed by multiple regression analyses. RESULTS: Between six and 10 years, adaptive fine motor tasks (40% vs. 17% of children scoring below 10th percentile) and MO (77% vs. 55%) improved significantly (both p<0.01), while all other components remained stable (pure motor 23% vs. 25%, adaptive gross motor 26% vs. 34%, static balance 18% vs. 20%, respectively). Mild neurological abnormalities at 6 years of age were associated with less improvement. CONCLUSION: Neuromotor functions improve in some children potentially reflecting catch up of maturational delay. However, the majority of neuromotor functions remain abnormal in a significant proportion of VLBW children.

[Developmental disorders in preschool children: an interdisciplinary approach]. / Entwicklungsstörungen im Vorschulalter - interdisziplinär beurteilt.

Many children show developmental abnormalities in the first years of life. Thus, the primary care physician should know the procedures of developmental surveillance and screening and be informed about the further steps in the evaluation of children with developmental disorders. This article presents current developmental screening methods in primary care, defines the terminology of developmental disorders in young children, demonstrates the essential diagnostic procedures in developmentally impaired children and describes the interdisciplinary collaboration between physicians, psychologists, therapists and special needs educators.

Visuomotor adaptation, internal modelling, and compensatory movements in children with developmental coordination disorder.

BACKGROUND: Developmental coordination disorder (DCD) is one of the most prevalent developmental disorders in school-aged children. The mechanisms and etiology underlying DCD remain somewhat unclear. Altered visuomotor adaptation and internal model deficits are discussed in the literature. AIMS: The study aimed to investigate visuomotor adaptation and internal modelling to determine whether and to what extent visuomotor learning might be impaired in children with DCD compared to typically developing children (TD). Further, possible compensatory movements during visuomotor learning were explored. METHODS AND PROCEDURES: Participants were 12 children with DCD (age 12.4 ± 1.8, four female) and 18 age-matched TD (12.3 ± 1.8, five female). Visuomotor learning was measured with the Motor task manager. Compensatory movements were parameterized by spatial and temporal variables. OUTCOMES AND RESULTS: Despite no differences in visuomotor adaptation or internal modelling, significant main effects for group were found in parameters representing movement accuracy, motor speed, and movement variability between DCD and TD. CONCLUSIONS AND IMPLICATIONS: Children with DCD showed comparable performances in visuomotor adaptation and internal modelling to TD. However, movement variability was increased, whereas movement accuracy and motor speed were reduced, suggesting decreased motor acuity in children with DCD.

Comparing neuromotor functions in 45- and 65-year-old adults with 18-year-old adolescents.

Aim: This cross-sectional analysis investigates how neuromotor functions of two independent cohorts of approximately 45- and 65-year-old individuals are different from 18-year-old adolescents using the Zurich Neuromotor Assessment-2 (ZNA-2). Methods: A total of 186 individuals of the Zurich Longitudinal Studies (ZLS) born in the 1950s (mean age 65.1 years, SD = 1.2 year, range of ages 59.0-67.5 years, n = 151, 82 males) and 1970s (mean age 43.6 years, SD = 1.3 year, range of ages 40.8-46.6 years, n = 35, 16 males) were tested with the ZNA-2 on 14 motor tasks combined in 5 motor components: fine motor, pure motor, balance, gross motor, and associated movements. Motor performance measures were converted into standard deviation scores (SDSs) using the normative data for 18-year-old individuals as reference. Results: The motor performance of the 45-year-old individuals was remarkably similar to that of the 18-year-olds (SDS from -0.22 to 0.25) apart from associated movements (-0.49 SDS). The 65-year-olds showed lower performance than the 18-year-olds in all components of the ZNA-2, with the smallest difference observed for associated movements (-0.67 SDS) and the largest for gross motor skills (-2.29 SDS). Higher body mass index (BMI) was associated with better performance on gross motor skills for 45-year-olds but with worse performance for 65-year-olds. More educational years had positive effects on gross motor skills for both ages. Interpretation: With the exception of associated movements, neuromotor functions as measured with the ZNA-2 are very similar in 45- and 18-year-olds. In contrast, at age 65 years, all neuromotor components show significantly lower function than the norm population at 18 years. Some evidence was found for the last-in-first-out hypothesis: the functions that developed later during adolescence, associated movements and gross motor skills, were the most vulnerable to age-related decline.

Secular trends in motor performance in Swiss children and adolescents from 1983 to 2018.

Introduction: Environmental changes, including globalization, urbanization, social and cultural changes in society, and exposure to modern digital technology undoubtedly have an impact on children's activity and lifestyle behavior. In fact, marked reductions in children's physical activity levels have been reported over the years and sedentary behavior has increased around the world. The question arises whether these environmental changes had an impact on general motor performance in children and adolescents. The study aimed to investigate secular trends of motor performance in Swiss children and adolescents, aged between 7 and 18 years, over a period of 35 years from 1983 to 2018. Methods: Longitudinal data on the five motor components of the Zurich Neuromotor Assessment (ZNA) - pure motor (PM), fine motor (FM), dynamic balance (DB), static balance (SB), and contralateral associated movements (CAM) - were pooled with cross-sectional data on PM and FM from eight ZNA studies between 1983 and 2018. Regression models were used to estimate the effect of the year of birth on motor performance and body mass index (BMI) measurements. Models were adjusted for age, sex, and socioeconomic status. Results: The secular trend estimates in standard deviation scores (SDS) per 10 years were - 0.06 [-0.33; 0.22, 95% Confidence Interval] for PM, -0.11 [-0.41; 0.20] for FM, -0.38 [-0.66; -0.09] for DB (-0.42 when controlled for BMI), -0.21 [-0.47; 0.06] for SB, and - 0.01 [-0.32; 0.31] for CAM. The mean change in BMI data was positive with 0.30 SDS [0.07; 0.53] over 10 years. Discussion: Despite substantial societal changes since the 1980s, motor performance has remained relatively stable across generations. No secular trend was found in FM, PM, SB, and CAM over a period of 35 years. A secular trend in DB was present independent of the secular trend in body mass index.

Long-term motor and cognitive outcome in children with congenital diaphragmatic hernia.

AIMS: To determine the motor and cognitive outcome in a regional cohort of survivors of surgically corrected congenital diaphragmatic hernia. METHODS: Thirty-three children (85% of survivors) were examined at a mean age of 8.6 years (3.3-15.7 years), seven had a genetic comorbidity. Outcome was assessed with the Wechsler Preschool and Primary Scale of Intelligence 3rd version and the Wechsler Intelligence Scale 4th version. Motor performance was tested with the Movement Assessment Battery for Children 2nd edition in children younger than 5 years and thereafter with the Zurich Neuromotor Assessment. RESULTS: Children without a genetic comorbidity had a normal cognitive outcome (median IQ 103, 70-121), but fine motor (p = 0.008) and gross motor outcome (p = 0.001) were poorer than the norm. Medical variables were not predictive of adverse outcome, whereas genetic comorbidity was the strongest predictor of low IQ (p < 0.001) and of poor motor performance (p = 0.04). CONCLUSIONS: In the absence of a genetic comorbidity, children with congenital diaphragmatic hernia have a favourable cognitive outcome, but motor outcome may be affected. This needs to be taken into account for parental counselling. Further, long-term neurodevelopmental assessment in children with congenital diaphragmatic hernia is important to provide early therapeutic interventions.

Impaired neuromotor outcome in school-age children with congenital hypothyroidism receiving early high-dose substitution treatment.

Congenital hypothyroidism (CH) can lead to intellectual deficits despite early high-dose treatment. Our study aimed to determine whether motor impairments can occur despite early high-dose treatment. Sixty-three children with CH and early (median age of onset of treatment 9 d), high-dose treatment (median starting dose of levothyroxine 14.7 µg/kg/d) were tested with the Zurich Neuromotor Assessment (ZNA) at a median age of 13.8 y (range 7.0-14.2 y). Median z-scores in the children with CH were -0.95 in the pure and -0.56 in the adaptive fine motor component, significantly lower than in the ZNA test norms (p < 0.001 and p = 0.01, respectively). The 26 children with athyreosis were more affected than the 33 children with dysgenesis, particularly in the pure motor (-1.55 versus -0.76, p = 0.03), adaptive fine motor (-1.31 versus 0.13, p < 0.01), and static balance task (-0.47 versus 0.67, p = 0.01). Boys performed worse than girls. Older age at onset of treatment was related to poorer adaptive fine motor performance. Movement quality (assessed by associated movements) was not affected. We conclude that severe CH can cause neuromotor deficits persisting into adolescence. These deficits cannot completely be reversed by postnatal treatment, but earlier age at treatment may reduce the degree of impairment.

Development of motor speed and associated movements from 5 to 18 years.

AIM: To study the development of motor speed and associated movements in participants aged 5 to 18 years for age, sex, and laterality. METHOD: Ten motor tasks of the Zurich Neuromotor Assessment (repetitive and alternating movements of hands and feet, repetitive and sequential finger movements, the pegboard, static and dynamic balance, diadochokinesis) were administered to 593 right-handed participants (286 males, 307 females). RESULTS: A strong improvement with age was observed in motor speed from age 5 to 10, followed by a levelling-off between 12 and 18 years. Simple tasks and the pegboard matured early and complex tasks later. Simple tasks showed no associated movements beyond early childhood; in complex tasks associated movements persisted until early adulthood. The two sexes differed only marginally in speed, but markedly in associated movements. A significant laterality (p<0.001) in speed was found for all tasks except for static balance; the pegboard was most lateralized, and sequential finger movements least. Associated movements were lateralized only for a few complex tasks. We also noted a substantial interindividual variability. INTERPRETATION: Motor speed and associated movements improve strongly in childhood, weakly in adolescence, and are both of developmental relevance. Because they correlate weakly, they provide complementary information.

The Importance of Childhood for Adult Health and Development-Study Protocol of the Zurich Longitudinal Studies.

Evidence is accumulating that individual and environmental factors in childhood and adolescence should be considered when investigating adult health and aging-related processes. The data required for this is gathered by comprehensive long-term longitudinal studies. This article describes the protocol of the Zurich Longitudinal Studies (ZLS), a set of three comprehensive cohort studies on child growth, health, and development that are currently expanding into adulthood. Between 1954 and 1961, 445 healthy infants were enrolled in the first ZLS cohort. Their physical, motor, cognitive, and social development and their environment were assessed comprehensively across childhood, adolescence, and into young adulthood. In the 1970s, two further cohorts were added to the ZLS and assessed with largely matched study protocols: Between 1974 and 1979, the second ZLS cohort included 265 infants (103 term-born and 162 preterm infants), and between 1970 and 2002, the third ZLS cohort included 327 children of participants of the first ZLS cohort. Since 2019, the participants of the three ZLS cohorts have been traced and invited to participate in a first wave of assessments in adulthood to investigate their current health and development. This article describes the ZLS study protocol and discusses opportunities, methodological and conceptual challenges, and limitations arising from a long-term longitudinal cohort recruited from a study about development in early life. In the future, the ZLS will provide data to investigate childhood antecedents of adult health outcomes and, ultimately, will help respond to the frequent call of scientists to shift the focus of aging research into the first decades of life and, thus, to take a lifespan perspective on aging.