ABC | Volume 114, Nº5, May 2020

Original Article Lima Campos et al. Knowledge about the congenital heart disease Arq Bras Cardiol. 2020; 114(5):786-792 Statistical analysis Categorical variables were described as absolute numbers and percentages, and the continuous variables as means and standard deviations. The Kolmogorov-Smirnov test was used in the distribution of continuous variables, where p >0.05 indicated symmetric data. To identify the factors related to the prevalence of IN/DK knowledge, a bivariate analysis was used with Pearson's Chi-square test complemented by the measure of crude Odds Ratio (OR) effect. 15 To verify the existence of differences between knowledge about CHD at different levels of physical activity, the One-way Analysis of Variance test with Sheffé post hoc test was performed. To assess the influence of the studied variables on the level of knowledge IN/DK, the Poisson regression model was used. In the composition of the model, the variables that obtained significance ≤ 0.200 in the unadjusted bivariate analysis were considered. In the adjusted analysis, the backward-stepwise method was used. Only variables associated with a p value <0.05 16 remained in the final model. A significance level of 5% was adopted for statistical decision criteria. The tests were performed with the software Statistical Package for Social Sciences 20.0 (SPSS Inc., Chicago, IL, USA, 2011) for Windows. Results The results presented herein are related to a sample of 335 children with CHD divided into three independent groups, according to the level of knowledge about the disease. Table 1 shows the overall sample characterization according to the classification about CHD knowledge. There was a predominance of the male gender (51.9%); age 10 years (21.2%), mean age of 10.5 ± 1.68 years; schooling between 4 th and 5 th grades (40.6%); acyanotic individuals with implications (55.5%); children who were hospitalized (67.2%); children not treated with surgical procedure (60%) and children practicing PA (90.1%). The DAFA instrument showed scores ranging from 2.0 to 92.0 points, with an average of 27.6 ± 14.2, median of 25.0 (1 st - 3 rd quartile: 16.0 - 36.0) points. Considering the PA level indicated by the instrument, it was verified through the quartiles that the low active cases had DAFA scores ≤ 16.0 points, while the highly active ones had scores ≥ 36.0 points. Regarding the comparison of the children's profile variables in relation to the knowledge level about CHD, there was a significant difference between the age groups (p = 0.033), level of schooling (p = 0.009), CHD classification (p<0.001), hospitalization (p = 0.044), surgical procedure (p = 0.015) and PA practice (p = 0.015). There was no significant difference (p = 0.285) between the level of PA assessed by DAFA with knowledge about CHD. According to Table 2, regarding the adjusted OR, the greatest univariate effects indicated that patients with a lower level of schooling (pre-school, 1 st , 2 nd and 3 rd grades) were 2.20 (95% CI: 1, 81-5.86) times more likely to answer incorrectly or did not know how to answer when compared to patients with a higher level of schooling, 8 th grade (p = 0.025). Regarding the classification of CHD, cyanotic patients were 2.29 (95% CI: 1.76-6.71) times more likely to answer incorrectly or did not know how to answer when compared to acyanotic patients with implications (p = 0.019). As for the practice of physical activity, patients who did not practice were 1.88 (95% CI: 1.09 3.34) times more likely to answer incorrectly or did not know how to answer when compared to patients who practiced PA (p = 0.011). Discussion The present study highlights the fact that most children and adolescents with CHD who participated in the interviews did not know how to say the name of their disease or explain it in their own words. Few studies have assessed the level of knowledge with the classification of heart disease or PA practice. The studies available in the scientific literature are difficult to standardize due to several methodological issues, including the absence of a validated questionnaire for children. In a descriptive study, most adolescents (54%) did not know the name of their heart defect compared to most of their parents (78%), who in turn knew the name of their child's heart defect correctly. However, only 24% of adolescents and 30% of parents were able to correctly locate the defective lesions on a heart diagram. 17 A study found that patients with mild CHD had more incorrect answers in a questionnaire about their disease, compared to patients with moderate CHD (p <0.001). 9 This finding differs from that found in the present study, in which cyanotic children answered incorrectly in relation to those with minimal lesions. A possible explanation for this is that patients who belonged to the disease group with less complex malformation and with minimal hemodynamic implications, would understand and explain their disease more easily, when compared to patients with cyanotic diseases, of which explanations are more complex. In turn, specific types of CHD have been associated with significant differences in the average Intellectual Quotient (IQ). 18 Children with cyanotic disease tend to have lower average IQs than children with acyanotic CHD, 19 which was not assessed in this study. After the implementation of a structured education program for adolescents and adults with CHD, a study found that an average total score of knowledge in the group that received educational intervention (57%) was significantly higher compared to the control group (43%) (p<0.001). However, only 24 patients (11%) in the intervention group achieved the objective proposed by the educational program. After adjusting for the patient’s age, level of schooling and disease complexity, the multivariate linear regression analysis showed that the provision of structured education for CHD was an independent determinant of higher levels of knowledge (p <0.001). Therefore, adolescents and adults with a higher level of schooling and higher disease complexity were significantly correlated with greater knowledge about their disease (p <0.001). 20 The practice of PA was associated with greater knowledge, and this may have occurred because children like to practice PA and/or parents are concerned about and questioned the limits 788