Evaluation of an instrument to assess the needs of patients with cancer

BACKGROUND. This study aimed to assess the face, content, and construct validity and the internal reliability of a tool for assessing the generic needs of patients with cancer (the Supportive Care Needs Survey). METHODS. A total of 1492 consecutive patients attending the surgical, radiation, or medical oncology departments of 9 cancer treatment centers in New South Wales, Australia, were asked to participate. Of the 1370 eligible patients, 1354 (99%) consented to participate and 888 (65%) completed the survey. Eligible consenting patients were given a Supportive Care Needs Survey to complete at home and return by mail within 7 days. RESULTS. In the assessment of construct validity, the principal components method of factor analysis identified 5 factors with eigenvalues greater than 1, which together accounted for 64% of the total variance (patients' needs in the domains of psychologic, health system and information, physical and daily living, patient care and support, and sexuality). Face and content validity were found to be high following pilot tests and tests of reading ease. Internal reliability coefficients (Cronbach alpha) of all 5 factor-based scales were found to be substantial, ranging from 0.87 to 0.97. CONCLUSIONS. These findings suggest that the Supportive Care Needs Survey provides a reliable and valid index of the global needs of oncology patients. The standardized and widespread application of this instrument is recommended following further refinement and evaluation.