Validation of a Single-Item Screener for Financial Toxicity in Outpatient Imaging Patients

Financial toxicity (FT) is associated with adverse clinical outcomes, highlighting the need for efficient screening approaches. We evaluated item 12 ("My illness has been a financial hardship to me and my family") of the COmprehensive Score for Financial Toxicity (COST) measure as a single-item screener for FT among patients scheduled for outpatient imaging.

We conducted a secondary analysis of 709 patients scheduled for outpatient imaging, including 427 who completed their appointments and 282 who canceled. Correlations between item 12 and the 11-item COST score were calculated. Item response theory analysis using a graded-response model was performed on the completed appointment sample, and predictive validity of item 12 was assessed in both groups via receiver operating characteristic curve analysis using two COST score thresholds for defining high FT.

Item 12 (reverse-scored) correlated strongly with the 11-item COST score (Spearman's r = 0.75 in the completed sample; r = 0.69 in the canceled sample). Item response theory analysis showed high discrimination for item 12 (α = 3.40), supporting its ability to capture varying FT levels. Receiver operating characteristic curve analysis using the two thresholds demonstrated excellent discrimination for identifying high FT, with area under the curve of 0.89 to 0.90 for the completed sample and 0.88 to 0.89 for the canceled sample.

COST item 12 is a valid and efficient single-item screener for FT. It can be implemented early in patients' treatment courses by screening in outpatient imaging settings, capturing patients across a broad spectrum of medical conditions while minimizing survey burden. This tool may facilitate early identification of patients in need of interventions.