Health related quality of life of children with rheumatic heart diseases: reliability of the Brazilian version of the Pediatric Quality of Life Inventory™ Cardiac Module scale.

Background: This study aimed to translate the 'Pediatric Quality of Life Inventory™ (PedsQL™ 3.0) Cardiac Module' into Portuguese, adapt it to Brazilian culture, and assess its psychometric properties (validity and reproducibility), and to calculate health-related quality of life scores on the PedsQL 4.0 and PedsQL™ 3.0 Cardiac Module Scales for a group of patients 5 to 18 years old with rheumatic heart disease.

Methods: The methods suggested by the authors of the original version of the questionnaire included 1) translation by an expert panel; 2) translation back into English and revision by the authors of the original version; 3) pilot study with seven children and parents in each of three age ranges (5 to 7, 8 to 12, and 13 to 18 years old); and 4) assessment of the measurement properties. In this stage, the PedsQL™ 3.0 Cardiac Module and the PedsQL 4.0 Generic Scale were applied to a sample comprising 109 children and adolescents with rheumatic heart disease and their parents or caregivers. The version for parents or caregivers was administered separately on the same day.

Results: The values of Cronbach's alpha for all scales assessed in the questionnaire (heart problems and treatment [symptoms], problems with perceived physical appearance, treatment anxiety, cognitive problems, and communication problems) varied from 0.6 to 0.8, indicating good internal consistency. Correlation was found between the scores for the Cardiac Module and the Generic Scale (0.36-0.86), demonstrating convergent validity (Spearman's correlation coefficient, p < 0.01). The symptoms, problems with perceived physical appearance, and cognitive and communication problem domains were able to distinguish between groups of patients with mild and moderate/severe heart disease (Student's t-test, p < 0.05). The intraclass correlation of the interobserver reproducibility was adequate (0.76 to 0.94 among the patients [children/adolescents] and 0.76 to 0.84 among their caregivers). The correlation between the patients' scores and their parents' scores varied from 0.50 to 0.86 (Pearson's correlation coefficient, p < 0.01).

Conclusions: The Brazilian version of the PedsQL™ 3.0 Cardiac Module was shown to be reliable. The application of this questionnaire in practice will be very useful for all professionals charged with the care of children and adolescents with heart diseases.