Development and psychometric evaluation of a Persian version of the Death Depression Scale-Revised: a crosscultural adaptation for patients with advanced cancer

Background: The surfacing of thoughts and depressive affect associated with the prospect of death are prevalent among patients with advancedcancer. Because death cognitions and associated negative affect occur along an adaptive-less adaptive continuum, it is essential that valid and reliable instruments are available to measure death depression.Aim: The present study aimed to determine the psychometric properties of the Death Depression Scale among Iranian patients with advanced cancer. Methods: About 497 cancer patients completed a Persian version of the 21- item Death Depression Scale-Revised. The face, content and construct validity of the scale were ascertained. Reliability was also assessed using internal consistency, construct reliability and intra-class correlation coefficient (ICC).Results: Construct validity determined one factor with an eigenvalue greater than 1. The model had a good fit (χ2 (179, N = 248) = 520.345, P < 0.001; χ2/df = 2.907, CFI = 0.916, TLI = 0.902, IFI = 0.917, SRMR = 0.049 and RMSEA = 0.088 (90% confidence interval = 0.079-0.097)) with all factors loadings greater than 0.5 and statistically significant. The internal consistency, construct reliability and ICC were greater than 0.70.Convergent validity of the scale was demonstrated. Implications for practice: The Persian version of the DDS-R has beendemonstrated in this article to be a useful tool for the assessment of deathrelated depression in Iranian patients experiencing advanced cancer. The psychometric properties of this scale indicated that this is a reliable and valid measure which can be used in Persian populations of patients with cancer.

Keywords:

Iran , advanced cancer , cancer patients , death depression , psychometric