Assessing unmet needs in patients with cancer: An investigation of differential item functioning of the Needs Evaluation Questionnaire across gender, age and phase of the disease.

Objective: The main aim of this study was to provide evidence of the broad employability of the NEQ with patients of different gender and age with cancer in different phases of the disease and care process, using an Item Response Theory (IRT) approach and investigating Differential Item Functioning (DIF).

Methods: The NEQ was completed by 762 patients visiting, consecutively, outpatient clinics or admitted to oncology wards. Patients included in the study had different primary tumor sites and were in different phases of the disease and care process. The properties of the questionnaire were analyzed by applying IRT to test how well each item of the scale concurs in measuring unmet needs, how reliable the whole scale is, and whether the scale was metrically invariant across gender, age, and phase of the disease.

Results: Results showed that the NEQ performed well in measuring unmet needs and measurement equivalence of the scale across gender, age, and phase of the disease was verified.

Conclusions: The current study supports the utility and broad employability of the NEQ, thus providing empirical evidence that it is psychometrically sound and metrically equivalent across different groups of cancer patients. As such, the scale could be an effective tool when planning psychosocial interventions to improve the care process and patients' quality of life.