The sample consisted of 140 children aged between 8 and 14 years, residing in Sakarya province. There were three groups of children in which children diagnosed with COVID-19 (Child+ group, n=17) from March 15 to May 15, 2020, COVID-19 negative children whose parent(s) were COVID-19 positive and isolated from their parent(s) (Parent+ group, n=59), and a randomly selected control group from the community sample (n = 64). The participants in the Child+ group had either one or both parents tested as Covid-19 positive. Only laboratory confirmed cases (SARS CoV-2 RNA detected by molecular method) were included in the study. The exclusion criteria were the presence of a neurological disease affecting cognitive functions, mental disability, and autism spectrum disorders. Figure 1 outlines the process of sample selection in all three groups.
Sociodemographic Data Form
The form was prepared by the researchers to examine sociodemographic variables that may be related to the influences of COVID-19 outbreak on mental health. The form includes questions such as age, gender, and education status.
The Screen for Child Anxiety and Related Disorders (SCARED)
The SCARED is a self-report scale containing 41 items that measures anxiety disorders in children developed by Birmaher et al. . To fill the scale, either the child is asked to read the items or someone else reads the items to the child and marks the most suitable option. The scale includes five factors: somatic/panic, generalized anxiety, social phobia or social anxiety, separation anxiety, and school phobia. Çakmakçı has established the reliability and validity of the Turkish version of the SCARED .
Children’s Negative Cognitive Errors Questionnaire (CNCEQ)
The CNCEQ was developed by Leitenberg et al.  and derived from cognitive theory that measures for types of cognitive errors: catastrophizing, overgeneralization, personalizing, and selective abstraction. CNCEQ is a Likert type scale and high scores indicate high levels of cognitive errors. Karakaya et al.  has established the reliability and validity of the Turkish version of the CNCEQ.
Pediatric Quality of Life Inventory (PedsQL)
The PedsQL, developed by Varni et al., evaluates the general quality of life of children and adolescents aged between 2 and 18 . There are four different forms for different age groups and the current study used 8-12 age form for 8-12 age group and 13-18 age form for 13-14 age group. The PedsQL includes four subscales: physical functioning (8 items), emotional functioning (5 items), social functioning (5 items), and school functioning (5 items). Çakın has established the reliability and validity of the Turkish version of PedsQL [24, 25].
The date of birth, diagnosis dates, and contact information of all COVID-19 patients were obtained from the Sakarya Provincial Health Directorate after the necessary permission was obtained for the study. Clinical psychologists contacted the parents of subjects whose age range matched the research criteria via phone and informed them about the study. Parental consent for participation was collected using an online form. Parents were required to fill in the sociodemographic questionnaire and children were asked to fill in the other instruments. Video calls were used to support subjects who faced difficulties in filling up their forms. Data compiled from the responses of 140 children were used for the statistical analyses performed for the study.
Statistical Program for Social Sciences 16 (SPSS 16) was used for data analysis. The suitability of numerical variables (numerical data) to normal distribution was investigated by visual (histograms analysis) and analytical (Kolmogorov–Smirnov Test and Shapiro–Wilk Tests) methods. The Mann–Whitney-U test was performed for the statistical evaluation of numerical data unsuitable for normal distribution between two sample groups, and the Kruskal–Wallis test was performed for the evaluations performed between more than two groups. The Bonferroni corrected Mann-Whitney U test was used in the event of significant differences (p < 0.05) found via the Kruskal–Wallis Test. Pearson Correlation Analysis was conducted to examine the associations between normally distributed numerical variables. Research data were evaluated considering a significance level of p < 0.05. Linear regression analysis was employed to examine the predictability of sociodemographic variables and the SCARED questionnaire scores of the Parent+ group that reported high anxiety levels. The independent variables in the model were selected from variables that met the criteria of evincing normal distribution conditions and demonstrating within-group p values less than 0.25 in statistical analyses.