The Treatment-induced Neuropathy Assessment Scale (TNAS): a psychometric update following qualitative enrichment

BACKGROUND: The validation of the Treatment-induced Neuropathy Assessment Scale (TNAS v2.0), a patient-reported outcome measure of symptoms associated with cancer treatment-induced peripheral neuropathy (TIPN), was previously reported. Further patient input (qualitative interviewing, cognitive debriefing) suggested that the measure should be modified to better reflect the TIPN experience. We report the performance of a revised version (TNAS v3.0) for assessing TIPN across cancer treatments. This TNAS version incorporates extensive patient input, in accordance with FDA guidance on the development of patient-reported outcomes measures. Patients with multiple myeloma, colorectal cancer, or gynecological cancer treated with bortezomib, oxaliplatin, or taxane–platinum combination therapy, respectively, completed the TNAS v3.0, European Organization for Research and Treatment of Cancer Chemotherapy-Induced Peripheral Neuropathy (EORTC-CIPN20), and a cognitive debriefing survey during a scheduled clinic visit. Patients also participated in in-depth qualitative interviews about their TIPN symptoms. The psychometric properties of the TNAS v3.0 were evaluated. RESULTS: Cognitive debriefing survey results were summarized and showed that most patients found the items easy to complete, comprehensible, acceptable, and not redundant. A notable change from TNAS v2.0 was the separation of “numbness” from “tingling,” although these 2 items remained the most severe, followed by a new “pain” item. The Cronbach coefficient alphas for the 9-item TNAS were 0.88 and 0.90 at the first and second administrations, respectively, indicating good reliability. The test–retest reliability of the TNAS was 0.97. The correlation coefficients for the 9-item TNAS and the EORTC-CIPN20 were 0.69 for the sensory subscale, 0.70 for the motor subscale, and 0.32 for the autonomic subscale, indicating good validity. CONCLUSION: This psychometric evaluation showed that the TNAS v3.0 is valid and reliable. Further research is needed to determine clinically meaningful differences in TNAS v3.0 scores and demonstrate its responsiveness over time.