Development and validation of a quality-of-life questionnaire for patients with oral potentially malignant disorders.

OBJECTIVE: The aim of this study was to develop and evaluate the validity and reliability of a quality-of-life (QoL) questionnaire for patients with oral potentially malignant disorders (OPMDs). STUDY DESIGN: For item generation, 15 personal interviews and three focus group discussions were conducted with OPMD patients existing QoL questionnaires were reviewed, and inputs from specialist clinicians (n = 10) were considered. Data collected from patients were analyzed by using NVivo. This led to the identification of themes, item writing, scaling, item reduction, formatting, and pretesting of the newly developed questionnaire. The validity and reliability of the questionnaire were assessed in a separate sample of 300 patients (150 each of patients with OPMD and healthy individuals). RESULTS: Sixty items were generated from the qualitative data and by reviewing existing questionnaires. After item reduction, the final questionnaire comprised 20 questions, which could be categorized under four domains. Exploratory factor analysis revealed a four-factor structure conforming to the four domains. The OPMD QoL questionnaire exhibited good discriminant and convergent validity, with OPMD patients reporting poorer QoL compared with healthy individuals and correlating significantly with existing questionnaires designed for similar purposes respectively. CONCLUSIONS: Our OPMD QoL questionnaire was found to be valid and reliable. We recommend that it be applied in epidemiologic and treatment studies of these disorders.