RESUMO
BACKGROUND: Cancer involves numerous physical, psychological and emotional changes and has a negative impact on patients. Although there are a wide variety of questionnaires for general use in patients with cancer, very few are available that assess the pain, disability and craniomandibular functionality of patients with head and neck cancer (HNC) in a more specific manner. The purpose of this study is to present the preliminary behavior of the CF-PDI in its reduced version adapted for patients with HNC. MATERIAL AND METHODS: A total of 61 patients with HNC were included in a study to preliminarily analyze the internal consistency of the instrument, the convergent validity and the floor and ceiling effects. All the patients completed the informed consent document and a battery of 5 questionnaires: The Numerical Rating Scale (NRS), the Tampa Scale for Kinesiophobia for Temporomandibular Disorders (TSK-TMD), the Pain Catastrophizing Scale (PCS), the Quality of Life Questionnaire in patients with HNC (QLQ-HN) and the reduced version of the Craniofacial Pain and Disability Inventory (CF-PDI-11). Patients also performed 2 physical tests: measurements of the pain threshold on the masseter muscle and on the distal phalanx of the first finger; and the maximum mouth opening in neutral head position. RESULTS: Cronbach's α coefficient showed a very high internal consistency of 0.92. In terms of convergent validity, a statistically significant correlation was found between the CF-PDI-11 and the following variables: NRS, TSK-TMD, PCS, QLQ-HN, the threshold of pain in the distal phalanx of the first finger and the maximum interincisal opening. However, 21.3% of patients obtained the lowest possible score. The strongest correlation was found between the CF-PDI-11 and the QLQ-HN (r = 0.85, p <0.01). CONCLUSIONS: The preliminary version of the CF-PDI-11 shows that it could be a valid and reliable instrument to measure pain, disability and quality of life in patients with HNC.