Methods
This prospective cohort, within a nested case-control study, included
all children consecutively tested with reverse-transcriptase polymerase
chain reaction (RT-PCR) for SARS-CoV-2 from nasopharyngeal/oropharyngeal
samples collected at RCH between 1st March and 31st
October 2020. SARS-CoV-2 positive (SARS-CoV-2[+]) children were age
and sex-matched to consecutively tested SARS-CoV-2 negative
(SARS-CoV-2[-]) controls at a ratio of 1:2. Negative controls used
for matching were chosen using the following sequential criteria; (1)
nearest chronological swab, (2) closest age match and (3) gender match.
Symptom data and past medical history was obtained via a questionnaire
completed by the child’s guardian and verified against the participant’s
electronic medical record. Cardiac disease was defined as any previously
diagnosed congenital heart disease (CHD) ranging from septal defects to
cyanotic congenital heart disease. Respiratory disease was defined as
previously diagnosed asthma, obstructive sleep apnoea (OSA),
bronchopulmonary dysplasia (BPD), cystic fibrosis (CF), primary ciliary
dyskinesia (PCD), interstitial lung disease (ILD), bronchiectasis or
neuromuscular weakness. This study received ethics approval from the RCH
Human Research Ethics Committee (HREC #37024).
Descriptive statistics were used to summarise the cohort
characteristics. Median and inter-quartile ranges were reported as data
were non-parametric. Statistical analysis was performed using Stata
Version 16.0 (Stata Corporation, College Station, Texas, USA). Pearson’s
chi-square test was used for comparison of categorical variables.