Validation of the Supportive Care Needs Survey - short form 34 with a simplified response format in men with prostate cancer

Objective The Supportive Care Needs Survey - short form (SCNS-SF34) is a commonly used instrument that assesses levels of unmet needs in cancer patients across five domains. Participants in a number of recent studies have experienced difficulties with the five-point, two-level response scale. This study aimed to validate the SCNS-SF34 with a simplified four-point response format in a large sample of Australian men with prostate cancer. Methods Three hundred thirty-two men with prostate cancer commencing external beam radiotherapy completed the SCNS-SF34 with revised response format, along with measures of psychological distress (Hospital Anxiety and Depression Scale) and quality of life (Expanded Prostate Cancer Index Composite - short form). Exploratory factor and parallel analyses were undertaken to examine the structure of the revised instrument. Reliability analysis was performed, and convergent and divergent validity were examined using a priori predictions. Results As with the original scale, a five-factor solution was indicated. Four of the five factors were identical to those reported in the original SNCS-SF34 validation study. Internal consistency was excellent, exceeding 0.8 for all five domains. Consistent with expectations, correlations between SCNS domains and Hospital Anxiety and Depression Scale subscales indicated moderate to large convergent relations (ranging from 0.31-0.67). Conclusions The SCNS-SF34 with revised response format maintained the same factor structure as the original, with five domains. This analysis demonstrates that the simplified response scale does not adversely affect the psychometric properties of the instrument. The SCNS-SF34 with revised response format is reliable, valid and more acceptable to cancer patients than its predecessor