Validation of the Korean Version of the Neck Dissection Impairment Index in Patients Who Underwent Neck Dissection

Background/Objectives: Shoulder function is an important aspect of health related quality of life (QOL). Neck dissection impairment index (NDII) is a simple shoulder-specific questionnaire. This study aimed to evaluate the association between QOL and NDII in patients who underwent neck dissection to validate the Korean version of NDII.Materials & Methods: This study enrolled 74 patients with head and neck cancer who underwent neck dissection from December 2013 to April 2014. Patients completed questionnaires on QOL including the European Organization of Research and Treatment of Cancer 30-item Core QOL questionnaire (EORTC QLQ-C30) and NDII which was translated into Korean. Validity was evaluated by calculating the Pearson correlation coefficient between NDII and EORTC QLQ-C30.Results: We compared preoperative, postoperative within a week, 1st and 3rd months NDII scores. The total NDII scores were 14.7, 47.4, 33.7 and 34.3 each. Clinical variables including gender, site of primary tumor, performing revision neck dissection, radiotherapy and flap reconstruction were not significantly associated with NDII. However NDII mean score of patients who underwent unilateral neck dissection over 3 levels is most increased after operation. During all periods NDII scores were significantly associated with functioning score. Although other scores are lower correlation than function scores, global health status scores and symptom scores are also correlation with NDII.Conclusion: NDII was valid instrument and can be used not only in the clinical practice to assess shoulder dysfunction but also in the simple instrument to evaluate global QOL in Korea patients with having neck dissection.