key: cord-0942406-t9f080f5
authors: Hemphill, Nicole M.; Kuan, Mimi TY.; Harris, Kevin C.
title: Reduced Physical Activity During COVID-19 Pandemic in Children with Congenital Heart Disease
date: 2020-05-05
journal: Can J Cardiol
DOI: 10.1016/j.cjca.2020.04.038
sha: a081c53538b1576bba8ea72cd6ad39c2daaf340f
doc_id: 942406
cord_uid: t9f080f5

Abstract Children with congenital heart disease (CHD) are at-risk for both COVID-19 and secondary cardiovascular outcomes. Their increased cardiovascular risk may be mitigated through physical activity, but public health measures implemented for COVID-19 can make physical activity challenging. We objectively measured the impact of the COVID-19 pandemic on physical activity, continuously measured by FitbitTM step-counts, in children with CHD. Step-counts were markedly lower in late March and early April 2020, compared to 2019 and to early March 2020. It is vital to understand how precautions for COVID-19 will impact the health of children with CHD, especially if they persist long-term.

Children with congenital heart disease (CHD) are a vulnerable population at-risk for severe infection with COVID-19; they also have increased cardiovascular risk. Physical activity is important for their health. We have observed a significant decline in physical activity in late March and early April, compared to 2019 and to earlier in 2020, associated with COVID-19 public health measures.

There is minimal data available about COVID-19 in children, especially those with underlying medical conditions who are at increased risk of severe infection. The April 6 th report from the Center for Disease Control COVID-19 Response Team showed that children with underlying medical conditions represent 23% of the total pediatric COVID-19 cases and 77% of those hospitalized. 1 In addition to this increased COVID-19 risk common to children with underlying medical conditions, those with congenital heart disease (CHD) are known to be at higher risk of secondary cardiovascular outcomes long-term. 2, 3 Physical activity is a modifiable risk factor that is particularly important for this high-risk population. 4 The impact of public health measures on vulnerable populations, such as children with CHD, is important to quantify. The duration of the public health measures is unknown but may last for a year or more. Data about collateral health impacts are needed to help inform policy makers about the pros and cons of such measures as the epidemiology of COVID-19 evolves.

Physical activity is important for cardiovascular health, as well as general health and quality of life, especially in patients with CHD. 4 During the COVID-19 pandemic, physical activity may be even more crucial, especially for at-risk groups, due to its physical and mental health benefits. 5, 6 Unfortunately, due to public health orders, recommendations to stay at home, school and park closures, and self-isolation by highrisk groups, it is more challenging than usual to continue normal physical activity patterns. 5, 6 Additionally due to patient and family concern about CHD children being particularly vulnerable, their social isolation and physical inactivity may be exacerbated more than the general population. To date, there is no objective data to demonstrate how physical activity patterns in children with CHD may have changed due to , or what impact this may have on these patients' health over the short-and longterm.

In this study, we aimed to quantify the change in physical activity observed during the early phase of the COVID-19 pandemic in children with CHD.

Data were collected as part of an ongoing prospective cohort study in children with moderate to severe CHD. The study was approved by the University of British Columbia

Research Ethics Board (H17-01233). Children ages 9-16 with coarctation of the aorta (COA), tetralogy of Fallot (TOF), transposition of the great arteries (TGA), or Fontan circulation (FON) were recruited between April 2017 and March 2020 at the British Columbia Children's Hospital (BCCH) Heart Centre in Vancouver, or partnership clinics throughout British Columbia (BC) and the Yukon. BCCH is the only pediatric tertiary hospital for the province and almost all patients with CHD in BC are followed in one of these settings. Participants were provided a Fitbit Charge 2 TM (Fitbit Inc, San Francisco, CA), and were asked to wear and sync the device regularly for 24 months. Wristband size and placement were in accordance with manufacturer guidelines. Fitbit TM data were collected and managed using Research Electronic Data Capture (REDCap) tools hosted at BCCH. 7, 8 Fitbit data were auto-exported to REDCap using application programming interface.

In the absence of any consensus on wear time validation for commercial trackers in children, we considered a day to be valid if they had ≥1000 steps. Weekly (Monday-Sunday) step-counts were calculated by averaging the step-counts from all the valid days of each week. We have previously validated this device for quantifying physical activity in children with CHD. 9 We defined meeting physical activity guidelines as having ≥12,000 steps per day. 9, 10 Step-count data were taken from the beginning of 2020 to April 5 th and compared to corresponding weeks in 2019.

Descriptive statistics (frequency [%] or mean ± standard deviation) were calculated for applicable variables. Distributions of continuous variables were assessed visually. The 'lowess' function in R was used to generate a physical activity lines of best fit from the Fitbit TM step-counts. Between-week differences were assessed via one-way ANOVA (post hoc Bonferroni correction). T-tests were used for continuous variables and chisquare tests for categorical variables. All analyses were performed in R (version 3.6.3) using R Studio (version 1.1.463) and significance was set at p < 0.05. 

During the early phase of the COVID-19 pandemic in Canada, children with CHD have had a decline of 21-24% of their overall daily step-counts. This reduction is likely due to COVID-19 measures and not Spring Break.

Step-counts during weeks 12 and 13 (Spring Break in both 2019 and 2020) are reduced in 2020 only, and this reduction persists into April.

Step-counts throughout the study period are below 12,000 per day (approximation of the Canadian physical activity guidelines). 9,10 This is unsurprising given that only one third of Canadian children, and only 25% of those with CHD, meet the guidelines. 11, 12 Therefore, reduced physical activity due to COVID-19 may not have severe long-term health impacts if the implemented measures to prevent a catastrophic pandemic are reasonably brief. However, it will be important to understand and model the long-term impact of significantly reduced physical activity on health for these patients should the present approach need to be maintained for months as indicated by Prime Minister Trudeau on April 8th. 13 These children are already at increased cardiovascular risk and physical inactivity has many other negative health consequences (e.g. bone health, motor skill development, body composition) which warrant consideration when making future public health decisions. 4, 14 The impact of reduced physical activity on population will depend on the duration of measures and the magnitude of reduction, so careful monitoring is required.

In addition to potential negative impacts on physical and cardiovascular health in this already at-risk population, mental health impacts of reduced physical activity must be considered. Physical activity is an important coping mechanism during the significant disruptions to normal routine caused by COVID-19. 6 In children with CHD this is particularly important, because they may have already had lower quality of life than their healthy peers prior to COVID-19, and physical activity has been associated with quality of life in children with CHD. 15, 16 Therefore it is necessary to evaluate the change in physical activity patterns due to COVID-19, and their potential long-term impacts on both the physical and mental health of this high-risk cardiac population.

Moving forward it will be important to consider how these children and their families may adapt to the public health precautions and resume higher levels of physical activity. If this is possible, or could be with appropriate intervention, then long-term negative health impacts due to reduced physical activity could be avoided. From January through early March, 2019 and 2020 step-counts are similar and increasing. Later in March, 2020 step-counts are significantly lower than 2019, despite seasonal match between the cohorts. It appears that this reduction is driven by reduced weekday step-counts, likely reflecting COVID-19-related disruptions to parents' and children's routines (work, school, extracurricular activities). Week 14 step-counts, though still lower than 2019, suggest a slight increase in physical activity from the previous week, which may reflect expected spring increase in physical activity and/or adaptive measures taken by families as COVID-19 measures extend. 17 The objective measurement of physical activity in this study provides the basis for future investigation of the long-term impacts of reduced physical activity during COVID-19 and how best to mitigate these. It will provide baseline data to investigate the necessity and effectiveness of supports for physical activity during and after the pandemic. This may provide an opportunity to assist children with CHD and their families in developing life-long physical activity habits that are less reliant on external factors (e.g. school, extracurricular physical activities), which are currently cancelled, but normally contribute to physical activity levels in school-aged children. 18 Physical activity monitoring throughout the COVID-19 pandemic and after will permit better understanding of the adaptability of children with CHD and their families, and may help generate and test hypotheses about individual and family based physical activity interventions.

To our knowledge this is the first study to report change in objectively measured physical activity in response to COVID-19 and associated precautions. A key strength of this study is the longitudinal data capture enabled by using Fitbits and the comparison data from both 2019 and early 2020. The main limitation to the study is that we used a single method to quantify physical activity and as such it is limited to only physical activity patterns indicated by step-counts, which do not reflect physical activity mode or intensity. A second limitation is the lack of healthy control comparison data, which are unavailable due to the nature of the ongoing cohort study limited to children with CHD.

Therefore, the generalizability of these data to healthy children may be limited.

This study provides important objective physical activity data in children with CHD, which will allow for future modeling of the potential impacts of COVID-19 on physical activity, and subsequently health depending on the duration and nature of public health measures going forward. Future studies will be needed to model these impacts and explore potential strategies for mitigation. Continuous physical activity monitoring data during this pandemic provides unique insight about the impact of COVID-19 and public health precautions on daily habits of children with CHD, which will hopefully inform clinicians about potential health impacts and help develop interventions if necessary, both during the pandemic, and in the future.

There is a paucity of pediatric COVID-19 data, specifically among children with underlying medical conditions, including CHD. Clinicians, policy makers, and other stakeholders need to consider the potential long-term and indirect health impacts of public health precautions in response to COVID-19. Children with CHD have significantly reduced physical activity compared to prior to the pandemic. The short-and long-term health impacts of this cardiovascular risk behavior change have not yet been elucidated and are in part dependent on the duration of the health measures and any action taken to mitigate the adverse effects of these measures. 

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Changing Landscape of Congenital Heart Disease

Cardiovascular Risk Reduction in High-Risk Pediatric Patients

Promotion of Physical Activity for Children and Adults With Congenital Heart Disease

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Physical exercise as therapy to fight against the mental and physical consequences of COVID-19 quarantine: Special focus in older people

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Daily step target to measure adherence to physical activity guidelines in children

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Return to work will be graduated and likely months off, Trudeau says. The Globe and Mail

Systematic review of the relationships between sedentary behaviour and health indicators in the early years (0-4 years)

Health-related quality of life outcomes in children and adolescents with congenital heart disease

Sports participation and quality of life in adolescents and young adults with congenital heart disease

Children with congenital heart disease exhibit seasonal variation in physical activity

Physical activity levels of Hungarian children during school recess

Note: Results are reported as frequency(percentage) or mean±standard deviation. *indicates significance. Week 1 begins on December 31 st

We would like to acknowledge the participants in this study and their families, as well as the clinical staff of the Children's Heart Centre who make clinically-integrated research recruitment possible.

This project was supported by a Grant-in-Aid from Heart & Stroke Canada (Grant # G-17-0018284).

None.