Psychometric properties of the Brazilian version of the Child Perceptions Questionnaire (CPQ11-14) - short forms

Background: The need to evaluate the impact of oral health has led to the development of instruments for measuring oral health-related quality of life (OHQoL). One such instrument is the Child Perceptions Questionnaire (CPQ(11-14)), developed specifically for 11-to-14-year-old children. As this questionnaire was considered long ( 37 items), shorter forms were developed with 8 ( Impact Short Form: 8 - ISF:8) and 16 items (Impact Short Form: 16 - ISF:16) to facilitate use in the clinical setting and population-based health surveys. The aim of the present study was to translate and cross-culturally adapt these CPQ(11-14) short forms for Brazilian Portuguese and evaluate the measurement properties of these versions for use on Brazilian children. Methods: Following translation and cross-cultural adaptation, the ISF:8 and ISF: 16 were tested on 136 children from 11 to 14 years of age in the city of Belo Horizonte, Brazil. The instrument was administered by a trained researcher who also performed clinical examinations. The measurement properties (i.e. criterion validity, construct validity, internal consistency reliability, test-retest reliability) were determined. Discriminant validity was tested between groups, which were divided into children with no cavities and no malocclusion; children with cavities and without malocclusion; and children with malocclusion and without cavities. Results: The mean total score was 6.8 [standard deviation (SD) 4.2] for the ISF:8 and 11.9 (SD 7.6) for the ISF: 16 (p < 0.001). Statistically significant associations were found between oral abnormalities and the subscales of the ISF: 8 and ISF: 16 (p < 0.05). Both test-retest stability and internal consistency, as measured by the intra-class correlation coefficient (ICC) (ISF:8 = 0.98 and ISF: 16 = 0.97) and Cronbach's alpha (ISF:8 = 0.70 and ISF:16 = 0.84) proved to be adequate. Construct validity was confirmed from the correlation between the short form scores and oral health and overall well-being ratings. The score on the short forms of the CPQ(11-14) was able to discriminate between different oral conditions. Criterion validity was satisfactory (p < 0.05). Conclusion: The Brazilian versions of CPQ(11-14) ISF:8 and ISF:16 have satisfactory psychometric properties, similar to those of the original instrument.