School-based Prospective Cohort Study Research Articles

Identifying latent classes of physical activity profiles over time among adolescents in Ontario, Canada

BackgroundPhysical activity behaviours are known to be highly correlated. Adolescents who participate in one type of physical activity (e.g., physical education) have a greater likelihood of participating in other physical activities (e.g., organized sports); however, little research has examined participation rates in various physical activity behaviours concurrently. This study identified longitudinal physical activity profiles among secondary school aged youth in Ontario, Canada.MethodsWe used data from the COMPASS Study, a school-based prospective cohort study of adolescents in Canada. Using a repeated measures latent class analysis, Ontario students who participated in grade 9 PE in 2015-16 were analysed through to 2018-19 (n = 1,917). Latent classes were defined by: PE participation, guideline adherence (≥ 60 min/day of moderate to vigorous activity over the last 7 days), and sport participation (varsity, community, and/or intramural). Multinomial logistic regression models were used to examine associations between latent class membership and student characteristics.ResultsThree distinct latent classes were identified for females and four were identified for males. These classes were: (1) Guidelines (high probability of guideline adherence; females: 44%; males: 16%), (2) PE & Sports (high probability of PE and sport participation; females: 33%; males: 43%), (3) Guidelines & Sports (high probability of guideline adherence and sport participation; females: 23%; males: 23%;), and (4) Inactive (low probability of all physical activity indicators; males: 18%). Strength training, sleep, and English grade were associated with class membership among females. Ethno-racial identity, weekly spending money, strength training, and English and math grades were associated with class membership among males.ConclusionsFindings suggest that latent physical activity profiles differ by sex. Guideline adherence was the most common class among females, indicating high levels of independent physical activity, whereas PE & Sport participation was the most common class among males, indicating greater tendency towards organized activities. Additionally, a substantial number of male students were not engaging in any physical activity. Participation in both PE and sports did not necessarily lead to meeting physical activity guidelines, highlighting that these activities alone may not be providing sufficient levels of physical activity that align with current recommendations for Canadian youth.

ASSOCIATION OF TESSELLATION DENSITY WITH PROGRESSION OF AXIAL LENGTH AND REFRACTION IN CHILDREN: An Artificial Intelligence-Assisted 4-Year Study.

To investigate fundus tessellation density (TD) and its association with axial length (AL) elongation and spherical equivalent (SE) progression in children. The school-based prospective cohort study enrolled 1,997 individuals aged 7 to 9 years in 11 elementary schools in Mojiang, China. Cycloplegic refraction and biometry were performed at baseline and 4-year visits. The baseline fundus photographs were taken, and TD, defined as the percentage of exposed choroidal vessel area in the photographs, was quantified using an artificial intelligence-assisted semiautomatic labeling approach. After the exclusion of 330 ineligible participants because of loss to follow-up or ineligible fundus photographs, logistic models were used to assess the association of TD with rapid AL elongation (>0.36 mm/year) and SE progression (>1.00 D/year). The prevalence of tessellation was 477 of 1,667 (28.6%) and mean TD was 0.008 ± 0.019. The mean AL elongation and SE progression in 4 years were 0.90 ± 0.58 mm and -1.09 ± 1.25 D. Higher TD was associated with longer baseline AL (β, 0.030; 95% confidence interval: 0.015-0.046; P < 0.001) and more myopic baseline SE (β, -0.017; 95% confidence interval: -0.032 to -0.002; P = 0.029). Higher TD was associated with rapid AL elongation (odds ratio, 1.128; 95% confidence interval: 1.055-1.207; P < 0.001) and SE progression (odds ratio, 1.123; 95% confidence interval: 1.020-1.237; P = 0.018). Tessellation density is a potential indicator of rapid AL elongation and refractive progression in children. TD measurement could be a routine to monitor AL elongation.

The Future Proofing Study: Design, methods and baseline characteristics of a prospective cohort study of the mental health of Australian adolescents.

The Future Proofing Study (FPS) was established to examine factors associated with the onset and course of mental health conditions during adolescence. This paper describes the design, methods, and baseline characteristics of the FPS cohort. The FPS is an Australian school-based prospective cohort study with an embedded cluster-randomized controlled trial examining the effects of digital prevention programs on mental health. Data sources include self-report questionnaires, cognitive functioning, linkage to health and education records, and smartphone sensor data. Participants are assessed annually for 5years. The baseline cohort (N=6388, M=13.9years) is broadly representative of the Australian adolescent population. The clinical profile of participants is comparable to other population estimates. Overall, 15.1% of the cohort met the clinical threshold for depression, 18.6% for anxiety, 31.6% for psychological distress, and 4.9% for suicidal ideation. These rates were significantly higher in adolescents who identified as female, gender diverse, sexuality diverse, or Aboriginal and/or Torres Strait Islander (all ps<0.05). This paper provides current and comprehensive data about the status of adolescent mental health in Australia. The FPS cohort is expected to provide significant insights into the risk, protective, and mediating factors associated with development of mental health conditions during adolescence.

Development and validation of a novel nomogram for predicting the occurrence of myopia in schoolchildren: A prospective cohort study

Myopia is a major public health issue and occurs at young ages. Apart from its high prevalence, myopia results in high costs and irreversible blinding diseases. Accurate prediction of the risk of myopia onset is crucial for its precise prevention. We aimed to develop and validate an effective nomogram for predicting myopia onset in schoolchildren. School-based prospective cohort study. A total of 1073 schoolchildren were enrolled from November 2014 to May 2019 in China, and were divided into the training and validation cohorts. Myopia was defined as a spherical equivalent refraction (SER) ≤-0.5 diopters. Predictors of myopia were determined through the least absolute shrinkage and selection operator regression and multivariable Cox proportional hazard model based on the training cohort. The predictive performance of the nomogram was validated internally through time-dependent receiver operating characteristic (ROC) curves, calibration plot, decision curve analysis, and Kaplan-Meier curves. Independent predictors at baseline including gender, SER, axial length, corneal refractive power, and positive relative accommodation were included in the nomogram prediction model. This nomogram demonstrated excellent calibration, clinical net benefit, and discrimination, with all the area under the ROC curves (AUCs) between 0.74 and 0.86 in the training and validation cohorts. The Kaplan-Meier curves showed that 3 distinct risk groups stratified through X-tile analysis were well discriminated and robust among subgroups. The Harrell's C-index and net reclassification improvement demonstrated that the nomogram substantially improved compared with previous models. An online myopia risk calculator was generated for better individual prediction. The nomogram provides accurate and individual prediction of myopia onset in schoolchildren. External validation is needed to verify the generalizability of this nomogram.

Blood Pressure Increase and Microvascular Dysfunction Accelerate Arterial Stiffening in Children: Modulation by Physical Activity.

BackgroundAtherosclerotic remodeling starts early in life and can accelerate in the presence of cardiovascular risk (CV) factors. Regular physical activity (PA) can mitigate development of large and small artery disease during lifespan. We aimed to investigate the association of changes in body mass index (BMI), blood pressure (BP), PA behavior and retinal microvascular diameters with large artery pulse wave velocity (PWV) in prepubertal children over 4 years.MethodsThe school-based prospective cohort study included 262 children initially aged 6–8 years, assessing the above CV risk factors and retinal vessels by standardized procedures at baseline (2014) and follow-up (2018). PWV was assessed by an oscillometric device at follow-up.ResultsChildren with increased systolic BP over 4 years showed higher PWV at follow-up (β [95% CI] 0.006 [0.002 to 0.011] mmHg per unit, P = 0.002). In contrast, increased vigorous PA corresponded to a lower PWV at follow-up (β [95% CI] −0.009 [−0.018 to <0−0.001] 10 min/day per unit, P = 0.047). Progression of retinal arteriolar narrowing and venular widening were linked to a higher PWV after 4 years (β [95% CI] −0.014 [−0.023 to −0.004] 0.01 changes per unit, P = 0.003).ConclusionIncrease in systolic BP and progression of microvascular dysfunction were associated with higher PWV after 4 years. Children with increasing levels of vigorous PA were found to have lower PWV at follow-up. Habitual vigorous PA has the potential to decelerate the process of early vascular aging in children and may thus help counteract CV disease development later in life.Clinical Trial RegistrationClinicalTrials.gov, Identifier: NCT03085498.

Seroprevalence and immunity of SARS-CoV-2 infection in children and adolescents in schools in Switzerland: design for a longitudinal, school-based prospective cohort study

ObjectivesThis longitudinal cohort study aims to assess the extent and patterns of seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies in school-attending children, and their parents and school personnel. It will examine risk factors for infection, the relationship between seropositivity and symptoms, and temporal persistence of antibodies.MethodsThe study (Ciao Corona) will enroll a regionally representative, random sample of schools in the canton of Zurich, where 18% of the Swiss population live. Children aged 5–16 years, attending primary and secondary schools, and their parents and school personnel are invited. Venous blood and saliva samples are collected for serological testing in June/July 2020, in October/November 2020, and in March/April 2021. Bi-monthly questionnaires will cover SARS-CoV-2 symptoms and tests, health, preventive behavior, and lifestyle information. Hierarchical Bayesian logistic regression models will account for sensitivity and specificity of the serological tests in the analyses and complex sampling structure, i.e., clustering within classes and schools.Results and conclusionsThis unique school-based study will allow describing temporal trends of immunity, evaluate effects of preventive measures and will inform goal-oriented policy decisions during subsequent outbreaks.Trial registration ClinicalTrials.gov Identifier: NCT04448717, registered June 26, 2020. https://clinicaltrials.gov/ct2/show/NCT04448717.

School-based epidemiology study of myopia in Tianjin, China

PurposeTo study the epidemiology of myopia in school-aged children in Tianjin and the relationship between visual acuity-based screening and refraction-based screening.MethodThis school-based prospective cohort study was performed on children from 42 elementary schools and 17 middle schools in Tianjin, China. Totally 14,551 children, ages ranging from 5 to 16 years, were included in this study. Uncorrected visual acuity (UCVA) was determined by logarithmic tumbling E chart. Non-cycloplegic photorefraction was examined by the Spot (v2.1.4) photoscreener. The relationship between the UCVA and refractive error was investigated for different age groups.ResultsThe overall prevalence of myopia at this school based screen is 78.2%, ranged from 10% at age of 5 to 95% at age of 16. The most dramatic increase in prevalence is from age of 6 (14.8%) to age of 7 (38.5%). The overall prevalence of high myopia is 2.5%. UCVA is found corresponding to spherical equivalent refraction (SER) in a manner of normal distribution and is significantly affected by age. When using UCVA to estimate the prevalence of myopia, the overall sensitivity and specificity are 0.824 and 0.820, respectively. Age-dependent optimal cutoff points and 95% confident intervals of such estimation are reported.ConclusionsMyopia is heavily affecting school-aged children in Tianjin, China. The refraction screening is preferable for myopia screening, whereas the UCVA screening results need to be interpreted in an age-dependent manner for myopia estimation.

Dengue Infection in Children in Fortaleza, Brazil: A 3-Year School-Based Prospective Cohort Study.

.Dengue is endemic in Brazil. The dengue surveillance system’s reliance on passive reporting may underestimate disease incidence and cannot detect asymptomatic/pauci-symptomatic cases. In this 3-year prospective cohort study (NCT01391819) in 5- to 13-year-old children from nine schools in Fortaleza (N = 2,117), we assessed dengue virus (DENV) infection seroprevalence by IgG indirect ELISA at yearly visits and disease incidence through active and enhanced passive surveillance. Real-time quantitative polymerase chain reaction (RT-qPCR) and DENV IgM/IgG capture ELISA were used for diagnosis. We further characterized confirmed and probable cases with a plaque reduction neutralization test. At enrollment, 54.1% (95% CI: 46.6, 61.4) of children were DENV IgG positive. The annual incidence of laboratory-confirmed symptomatic dengue cases was 11.0 (95% CI: 7.3, 14.7), 18.1 (10.4, 25.7), and 10.2 (0.7, 19.7), and of laboratory-confirmed or probable dengue cases with neutralizing antibody profile evocative of dengue exposure was 13.2 (6.6, 19.9), 18.7 (5.3, 32.2), and 8.4 (2.4, 19.2) per 1,000 child-years in 2012, 2013, and 2014, respectively. By RT-qPCR, we identified 14 DENV-4 cases in 2012–2013 and seven DENV-1 cases in 2014. During the course of the study, 32.8% of dengue-naive children experienced a primary infection. Primary inapparent dengue infection was detected in 20.3% (95% CI: 13.6, 29.1) of dengue-naive children in 2012, 8.7% (6.9, 10.9) in 2013, and 5.1% (4.4, 6.0) in 2014. Our results confirmed the high dengue endemicity in Fortaleza, with active and enhanced passive surveillance detecting three to five times more cases than the National System of Disease Notification.

Effects of physical activity and sedentary behaviour on cardiometabolic risk factors and cognitive function in children: protocol for a cohort study

IntroductionAlthough studies showed that physical activity (PA) and sedentary behaviour (SB) were associated with cardiometabolic risk factors and cognitive function, both independent and combined associations among them are inconsistent. Cardiometabolic...

The most physically active Danish adolescents are at increased risk for developing spinal pain: a two-year prospective cohort study

BackgroundThe overall aim of this study was to determine to what extent objectively measured physical activity in a school-based sample aged 11–13 years predicted incident cases of spinal pain (neck...

No associations between objectively measured physical activity and spinal pain in 11-15-year-old Danes.

Physical activity is thought to play a role in spinal pain (neck pain, mid back pain, low back pain) in children and adolescents, either as a risk or protective factor, but current evidence is conflicting. The overall aim of this study was to determine the cross-sectional and longitudinal associations between different levels of objectively measured physical activity, i.e. sedentary; moderate and vigorous; vigorous physical activity, and spinal pain in 11-15-year-old Danes. Data were collected at baseline (2010) (n=906) and at follow-up 2years later (n=625) in a school-based prospective cohort study. Physical activity was measured using the Actigraph GT3X TriaxialActivity Monitor, which measures the intensity of physical activity overtime. This was worn for 1week and spinal pain was assessed via e-survey that participants completed during school time. Potential confounders included in the multivariable analyses were sex, anthropometry, physical fitness, social status and psychosocial factors. In the longitudinal study, analyses stratified by baseline pain status were performed. There were neither cross-sectional nor longitudinal associations between different levels of objectively measured physical activity and spinal pain over the 2-year period. Objectively measured physical activity was not associated with spinal pain. However, it remains to be seen whether there is an association over a longer follow-up period. Future research should focus on the more qualitative aspects of physical activity, such as different sports activities.

Spinal pain in adolescents: prevalence, incidence, and course: a school-based two-year prospective cohort study in 1,300 Danes aged 11–13

BackgroundThe severity and course of spinal pain is poorly understood in adolescents. The study aimed to determine the prevalence and two-year incidence, as well as the course, frequency, and intensity of pain in the neck, mid back, and low back (spinal pain).MethodsThis study was a school-based prospective cohort study. All 5th and 6th grade students (11–13 years) at 14 schools in the Region of Southern Denmark were invited to participate (N = 1,348). Data were collected in 2010 and again two years later, using an e-survey completed during school time.ResultsThe lifetime prevalence of spinal pain was 86% and 89% at baseline and follow-up, respectively. A group of 13.6% (95% CI: 11.8, 15.6) at baseline and 19.5% (95% CI: 17.1, 22.0) at follow-up reported that they had pain frequently. The frequency of pain was strongly associated with the intensity of pain, i.e., the majority of the participants reported their pain as relatively infrequent and of low intensity, whereas the participants with frequent pain also experienced pain of higher intensity. The two-year incidence of spinal pain varied between 40% and 60% across the physical locations. Progression of pain from one to more locations and from infrequent to more frequent was common over the two-year period.ConclusionsSpinal pain is common at the age of 11–15 years, but some have more pain than others. The pain is likely to progress, i.e., to more locations, higher frequency, and higher pain intensity over a two-year period.

Obesity and the occurrence of bronchitis in adolescents

Previous studies have shown that an elevated BMI was associated with higher risks of bronchitis among children. The magnitude of how increase in BMI influencing the risk of incident bronchitis remained unexplored. The objective of this study is to assess the association between BMI and the incidence of bronchitis in the Taiwan Children Health Study. A school-based prospective cohort study. We conducted a population-based prospective cohort study among seventh-grade school children in 14 Taiwanese communities. A total of 3,634 adolescents completed follow-up questionnaire in 2009. Associations between BMI and incident bronchitis were analyzed by multiple Poisson regression models, taking overdispersion into account. Among eligible cohort participants without bronchitis at study entry, the proportion of overweight and obesity were 32.1% and 17.9%. Overweight was 40.7% and obesity was 27.7% among those with incident bronchitis. The BMI percentile categories showed significant increasing trends for bronchitis in total eligible children and in girls (P for trend <0.001). Overweight and obesity were both associated with increased risks of incident bronchitis. This association was significant in girls only while stratified by gender. Our data showed that the BMI percentile and weight status were associated with higher risks of incident bronchitis in adolescents, especially in girls.