Adaptation of the City of Hope-Quality of Life-Ostomy Questionnaire From English to Brazilian Portuguese

A Validation Study

Abstract

PURPOSE: 

To culturally adapt the City of Hope-Quality of Life-Ostomy Questionnaire (COH-QOL-OQ) from English to Brazilian Portuguese and evaluate psychometric properties of the adapted instrument (internal consistency and construct validity).

DESIGN: 

Methodological study to establish reliability and validity.

SUBJECTS AND SETTING: 

The sample comprised 215 persons with stomas of any etiology who attended 1 of 3 specialized outpatient care center and 2 associations for persons with ostomies. Participants were residents of the state of Rio Grande do Sul, located in southeastern Brazil.

METHODS: 

Techniques for cultural adaptation were carried out based on recommendations from the literature. We then evaluated the instrument's psychometric properties. Specifically, we evaluated construct (convergent and discriminant) validity and concurrent criterion validity via comparison of the adapted version of COH-QOL-OQ versus the WHOQOL-Bref (World Health Organization Quality of Life instrument). We also evaluated the internal consistency of the adapted COH-QOL-OQ, a measure of reliability.

RESULTS: 

The internal consistency of the items was high with a Cronbach α of 0.92 for the total score and values ranging from 0.79 to 0.86 for the various domains of the COH-QOL-OQ. Confirmatory factorial analysis identified adjustment indexes to the acceptable model of adjustment for the COH-QOL-OQ model. Strong correlations between the COH-QOL-OQ and WHOQOL-Bref instrument domains confirmed the validity of the convergent construct. For the analysis of the concurrent criterion validity, the correlation coefficients between the score of item 16 and the other domains of COH-QOL-OQ ranged from 0.26 to 0.66. Analysis of the discriminate validity indicated that it was possible to isolate groups based on the temporal character of the stoma and time since ostomy surgery.

CONCLUSIONS: 

The adapted version of COH-QOL-OQ demonstrates construct (convergent and discriminant) validity, concurrent criterion validity, and internal consistency (a measure of reliability) for evaluating health-related quality of life of persons with ostomies living in Brazil.