Evaluation of the Distress Thermometer in Pelvic Exenteration: Responsiveness-To-Change, Convergent Validity, and Clinical Cutoff.

Abstract

Pelvic exenteration (PE) is a radical surgery for advanced pelvic malignancies that carries substantial psychosocial impacts. Assessing distress is critical for timely support. To evaluate the responsiveness-to-change and convergent validity of the distress thermometer (DT), and to determine an optimal cutoff score for detecting clinically significant distress in a PE cohort. Secondary analyses of cohort study data involving adult patients who underwent PE at a quaternary referral hospital. Responsiveness was evaluated by determining whether the DT differentiated cases of decreased emotional well-being and health-related quality of life from pre- to post-surgery, using the Functional Assessment of Cancer Therapy-General (FACT-G), FACT-Colorectal, and Emotional Well-Being (EWB) subscale as external criteria. Convergent validity was evaluated using the correlation between the DT and the EWB subscale scores. Cutoff scores were examined by reviewing the following indices, using an existing EWB cutoff as an external anchor: sensitivity, specificity, positive/negative predictive values, and clinical utility index (CUI). The analysis included 377 patients (mean age: 61 years, 56% male; 41% recurrent rectal cancer). The DT demonstrated responsiveness, with AUCs > 0.7 for detecting emotional and quality-of-life decline post-surgery. Convergent validity was demonstrated through a moderate correlation between the DT and the EWB subscale scores (r_s = -0.56, p < 0.001). The optimal DT cutoff score was 4: Sensitivity; 87.0%, Specificity; 52.7%, CUI- value; 0.49 (ruling out cases: satisfactory utility), CUI+ value; 0.33 (case finding: poor utility). The DT is a valid and responsive tool for detecting psychological distress in PE patients. Its high sensitivity supports its use in routine screening.