Development and Validation of the Cancer Psychological Distress Questionnaire and Life Cost Scale: A Prospective Study

Introduction: Cancer continues to be a major global health burden, with increasing incidence and improved survival owing to advances in multimodal treatments such as Radiotherapy (RT). However, patients undergoing RT often experience significant psychological distress and financial toxicity, which are not adequately captured by existing generic assessment tools. Aim: To develop and preliminarily validate two context-specific patient-reported outcome measures the Cancer Psychological Distress Questionnaire (CaPSY-D) and the LifeCost Scale (Financial Burden Questionnaire) for assessing psychological distress and financial burden among cancer patients undergoing RT. Materials and Methods: The present prospective instrumentdevelopment and validation study was conducted from September 2025 to February 2026 in the Department of Radiation Oncology at a tertiary cancer hospital in Belagavi, Karnataka, India. Three stages were included in instrument development: (i) item generation through a systematic literature review; (ii) content validation by a panel of 12 multidisciplinary experts using Content Validity Index (CVI); and (iii) pilot testing with 20 radiation patients. Cronbach’s alpha was used to assess internal consistency reliability, and Friedman’s test -the appropriate non parametric test for ordinal, polytomous Likerttype data collected under a repeated-measures design was used to evaluate item homogeneity, restricted to the 20 pilot patients. Bartlett’s Test of Sphericity along with the Kaiser-Meyer-Olkin (KMO) measure of sampling adequacy was also computed. Results: A total of 20 subjects participated in the study, including 10 males and 10 females. The overall mean age was 50.6 years, with mean ages of 48.0 years and 53.2 years for males and females, respectively. Based on the pilot patient sample (n=20), Cronbach’s alpha values were 0.946 for CaPSY-D and 0.882 for the LifeCost Scale, indicating excellent and good internal consistency, respectively. Friedman’s test showed no statistically significant differences among items for either scale (CaPSY-D: χ2 =28.705, df=24, p=0.231; LifeCost Scale: χ2 =3.855, df=14, p=0.996), supporting item homogeneity. Bartlett’s Test of Sphericity remained significant for both scales (p<0.001); however, given the low KMO values obtained, this finding indicates sufficient inter-item correlations for exploratory analysis rather than established construct validity, which would require a larger confirmatory sample. Conclusion: The CaPSY-D and LifeCost Scale demonstrated good preliminary reliability and validity as context-specific tools for assessing psychological distress and financial toxicity in RT patients. These instruments may aid in early identification of vulnerable patients and support targeted interventions in routine oncology practice.