Designing and psychometrics properties of Existential Guilt Questionnaire in cancer patients

Clinically, existential issues are of significant importance in cancer patients, particularly existential guilt. To measure this construct, a suitable tool is needed. Therefore, this study aimed to design and validate the Existential Guilt Questionnaire (EGQ) in cancer patients.

This study employed a sequential exploratory mixed-method design for tool development. In the qualitative phase of tool design, the hybrid concept analysis method was used to explain the concept of existential guilt and generate items. Subsequently, psychometric properties such as face and content validity, construct validity through exploratory and confirmatory factor analysis, and reliability through internal consistency (Cronbach's alpha) and stability (relative and absolute reliability) were assessed.

The 27- item EGQ, rated on a five-point Likert scale, was obtained with these psychometric properties: face validity (Impact Score > 1.5), content validity ratio (CVR > 0.62), average content validity index (SCVI/Ave > 0.8), exploratory factor analysis with four factors (unlived life, being another, dialogical or interpersonal dimension, and incompleteness) with a cumulative variance of 40.3%, and good fit indices in confirmatory factor analysis including RMSEA =0.07, χ^2/df = 2.50, comparative fit index (CFI) = 0.91, and incremental fit index (IFI) = 0.91. Additionally, internal consistency reliability (α = 0.87), relative reliability (ICC = 0.985), and absolute reliability (SEM = 2.29), interpretability, responsiveness, and ceiling and floor effects were obtained.

This valid and reliable questionnaire for measuring existential guilt in cancer patients helps therapists assess patients in this regard and implement therapeutic interventions in response to this issue.