Development and Psychometric Validation of the TF-Col: A Patient- and Caregiver-Reported Measure of Financial Toxicity in Oncology.

OBJECTIVES

To develop and psychometrically validate the TF-Col, a patient- and caregiver-reported outcome measure to assess financial toxicity in adult and pediatric oncology populations in a middle-income Latin American context.

METHODS

A multicenter study following Consensus-based Standards for the Selection of Health Measurement Instruments recommendations and guided by an evidence-centered design framework was conducted. The final 20-item scale was administered to 348 participants (200 adult cancer patients and 148 caregivers of pediatric patients). Psychometric evaluation included internal consistency, exploratory and confirmatory factor analyses using polychoric correlations, bifactor modeling, and item response theory analyses. Construct and convergent validity were examined using Spearman correlations with the Comprehensive Score for Financial Toxicity and the Pediatric Quality-of-Life Inventory.

RESULTS

The TF-Col showed excellent internal consistency for the total score (α = 0.957) and both domains. Exploratory analyses supported a dominant underlying dimension, whereas confirmatory factor analysis demonstrated superior fit for a correlated 2-factor model (CFI = 0.984; root mean square error of approximation = 0.043). A bifactor analysis supported the total score as the primary interpretive index (ωh = 0.700; Explained Common Variance = 0.694), with domain scores retaining descriptive value. item response theory analyses indicated adequate to high item discrimination and greatest measurement precision at low to moderate levels. Strong negative correlations were observed with the Comprehensive Score for Financial Toxicity (ρ = -0.785), and moderate negative correlations with caregiver-reported Pediatric Quality-of-Life Inventory scores.

CONCLUSION

The TF-Col demonstrated strong reliability, evidence of internal structure, and convergent validity in adult cancer patients and caregivers of children with cancer. These findings support its intended use as a contextually relevant measure for clinical assessment, outcomes research, and health system evaluation in oncology care.