Objectives: To establish the reliability and validity of a new self-administered questionnaire to assess valved speech and its related issues in patients who have undergone a total laryngectomy operation.
Design: Cross-sectional psychometric validation study.
Setting: Tertiary cancer care centre.
Patients: We identified sixty-one total laryngectomy patients with no sign of recurrent disease and using voice prothesis from the speech and language therapy database of the Royal Marsden Hospital. The patients were assessed using a postal self-administered voice prosthesis questionnaire concerning the voice valve and it's related issues. Patients were also asked to complete the University of Michigan voice related quality of life and University of Washington head and neck quality of life (version 4) questionnaires.
Main outcome measures: Test-retest and internal consistency reliability; content; criterion and construct validity.
Results: We received completed questionnaires from fifty-one of the sixty-one total laryngectomy patients identified for the study providing a response rate of 84%. The median age of the group was 65 years (range: 40–85) with thirty-seven males and fourteen females. The internal consistency reliability using the Cronbach's alpha coefficient was 0.87 (range: 0.85 to 0.89). Test-retest reliablility showed that more than 75% of patients had a score on re-test that was within 1 point of their original score. Content validity was ensured during the design process. The median Spearman correlation coefficient was 0.25 for convergent construct validity with the University of Washington head and neck quality of life questionnaire and 0.64 for criterion valididty on comparison with the University of Michigan voice related quality of life scale.
Conclusions: The voice prosthesis questionnaire is the first validated and reliable self-administered questionnaire designed specifically for evaluating valved speech and its related issues in patients who have undergone total laryngectomy. The voice prosthesis questionnaire has significant utility for audit, outcomes research and monitoring in this unique group of patients.