Speech handicap index: cross-cultural adaptation and validation in European Portuguese speakers with oral and oropharyngeal cancer

Introduction: To date, no valid outcome measure has been developed in European Portuguese (EP) to assess the opinion of the patients with oral and oropharyngeal cancer about the speech impact in his/her related quality of life. Objectives: This study aimed to cross-culturally adapt the speech handicap index (SHI) in EP and contribute to its validation in oral and oropharyngeal cancer patients. Materials and methods: A cross-sectional study was carried out in two phases: (i) SHI translation, back-translation, expert analysis, and pilot study; (ii) application of the EP version of the SHI (EP-SHI) to 95 patients with oral and oropharyngeal cancer and 83 gender- and age-matched healthy individuals. A total of 23 randomly chosen patients were asked to re-fill the EP-SHI questionnaire after 3 weeks. The psychometric properties (feasibility, practicability, reliability, and validity) were assessed. Results: The EP-SHI version brought together expert consensus and the acceptability of 75% of the participants in the pilot study. The EP-SHI questionnaire is feasible (no missing data and floor effect < 7%), practical (an average of 5.5 min to complete), possesses internal consistency reliability (Cronbach's alpha >= 0.90), test-retest reliability (interclass correlation coefficient, ICC >= 0.90), significantly strong convergent validity with EP-voice handicap index (VHI) (ro >= 0.94), distinguishes patients from healthy speakers and within the patients' group according to individual speech rating and glossectomy surgery. Conclusions: The EP-SHI is a culturally relevant, valid and reliable patient reported outcome measure (PROM), and therefore, it is appropriate to be recommended for used with oral and oropharyngeal cancer patients.