Development and Evaluation of Alternate Short Forms of the Child Oral Health Quality of Life Questionnaire

Objective: The objective of this study was to develop and evaluate alternate short-form versions of the 39-item Child Perceptions Questionnaire (CPQ). This forms one component of a multi-dimensional measure, the Child Oral Health Quality of Life Questionnaire designed to assess the health-related quality of life of children with dental and oro-facial conditions. Methods: The CPQ was developed using a multistage process. Its validity and reliability were assessed in a study involving 123 children from three clinical groups; dental, orthodontic and oro-facial. Of these 65 provided data for test retest reliability. Two 18-item short-forms were developed; one using a controlled regression technique (regression short-form) and the other using an item impact technique (impact short-form). They were constructed so each had four items that addressed oral symptoms, functional limitations and emotional well being and six items that addressed social well being. Their technical properties were compared using data from the validity and reliability study. Results: The two short forms shared 10 of their 18 items. Internal consistency reliabilities were 0.86 for the regression short form and 0.84 for the impact short form. Sub-scale alphas were consistently higher for the impact short form. Test-retest reliabilities were identical with ICCs of 0.87 (p<0.0001). Scores from the impact short form discriminated between the three clinical groups in the study (p<0.05), while scores from the regression short form did not. However, both showed good construct validity with significant associations with global ratings of oral health (p<0.05) and overall well being (p<0.01). Conclusions: Both short-forms of the CPQ had good technical properties. However, the item impact short form discriminated between the clinical groups included in the study while the version developed using a regression approach did not. Consequently, the former is preferable in studies requiring a discriminative instrument. Supported by Hospital for Sick Children Foundation Grant XG99-085.