Validation of "Cancer Dyspnea Scale" in Patients With Advanced Cancer in a Palliative Care Setting in India.

Abstract

Assessment of dyspnea in patients with advanced cancer is challenging. Cancer Dyspnea Scale (CDS) is a multidimensional scale developed for the measurement of dyspnea. It is available only in Japanese, English, and Swedish and has not been validated before in the Indian languages. The objective was to describe the process of validation and reliability testing of CDS in Indian advanced cancer patients. This is a prospective observational study conducted in the palliative care clinic of a tertiary cancer center in Mumbai. The English version of CDS was translated into Indian languages-Hindi (CDS-H) and Marathi (CDS-M). One hundred twenty newly registered eligible patients (60 for CDS-H and 60 for CDS-M) were enrolled into the study consecutively. They were asked to fill CDS (translated version) and Visual Analogue Scale for dyspnea. Only baseline measures were used. Validity was separately analyzed for CDS-H and CDS-M. The results showed good construct validity between CDS-H and CDS-M. Intersubscale correlation was done by calculating the Pearson's correlation coefficient (mean r = 0.64 and 0.764 for CDS-H and CDS-M, respectively). Convergent validity was calculated by computing the correlation of each factor with VAS-D scores and was found statistically significant (P < 0.001; average r ranging from 0.706 to 0.714). Reliability of the scale was determined by its internal consistency (Cronbach's alpha coefficient ranging from 0.716 to 0.879). This study demonstrates that CDS-H and CDS-M are valid and reliable multidimensional scales, which can be used to assess dyspnea in patients with advanced cancer.