Reliability of a multidimensional questionnaire for adults with treated complete cleft lip and palate

The purpose of this study was to evaluate the reliability of a multidimensional questionnaire for Swedish adults with treated complete unilateral or bilateral cleft lip and palate (CLP). The questionnaire was designed to be used in the evaluation of adults with treated CLP after treatment. Before any conclusions were drawn from the results of the study we assessed the test-retest reliability of the questionnaire. The questionnaire included 168 questions and assessed the following domains: aesthetics, functions associated with CLP, satisfaction with treatment and perceived need for treatment, quality of life, depression and non-specific physical symptoms, body image, and jaw function. The subjects answered the questionnaire twice at a 2-3-week interval. Sixty-one adults (38 men, 23 women) mean age 24 years (range 20-29) participated in the study. The response rate for the questionnaire was acceptable at 75%. The test-retest reliability varied among the different domains. The reliability of questions regarding aesthetics, functions associated with CLP, and treatment satisfaction was good to excellent (intraclass correlation coefficient (ICC) = 0.51 to 0.89). Good to excellent (ICC = 0.61 to 1.0) reliability was also found for the quality of life in various life domains and the wellbeing scales. The reliability of the body image scale was moderate (kappa = 0.43-0.60) for most items and lower than that of other scales used in this study. The reliability of the mean depression symptom score (ICC = 0.93) and the mean non-specific physical symptoms score (ICC = 0.85) were excellent. The reliability of the mandibular function impairment was good (ICC = 0.67). The conclusion of the study is that an overall reliability was good for the multidimensional questionnaire.