MEASURING PATIENT-REPORTED DERMATOLOGIC SIDE EFFECTS OF CANCER TREATMENT: PSYCHOMETRIC EVALUATION OF THE SKINDEX-16 IN NON-SMALL CELL LUNG CANCER
Author(s)
Julia Schuchard1, Stefan Englert, PhD2, Mehregan Nematian-Samani, MD2, Jairo Simoes, MD3, Yichuan Xia, PhD4;
1Johnson & Johnson, Associate Director, PROs, Philadelphia, PA, USA, 2Johnson & Johnson, Neuss, Germany, 3Johnson & Johnson, Raritan, NJ, USA, 4Johnson & Johnson, Wayne, PA, USA
1Johnson & Johnson, Associate Director, PROs, Philadelphia, PA, USA, 2Johnson & Johnson, Neuss, Germany, 3Johnson & Johnson, Raritan, NJ, USA, 4Johnson & Johnson, Wayne, PA, USA
OBJECTIVES: Reliable, valid measures of patient-reported treatment tolerability are important to complement clinicians’ reporting of adverse events in clinical trials. This study focused on skin-related symptoms commonly associated with epidermal growth factor inhibitors used to treat certain types of cancers. The objective of the analyses was to evaluate the validity evidence and meaningful change thresholds of the SKINDEX-16 for the evaluation of dermatologic symptoms and impacts in patients with non-small cell lung cancer (NSCLC) treated with amivantamab.
METHODS: The study included data from 199 adults (median age = 63 years) in the Phase 2 COCOON randomized trial, which evaluated the impact of enhanced versus standard dermatologic management on adverse events among patients with EGFR-mutated NSCLC treated with amivantamab and lazertinib. Participants completed the SKINDEX-16, EORTC QLQ-C30, and a single-item patient global impression of skin symptom severity (PGI-S) at study baseline and every two weeks for the first 12 weeks post-baseline. The PGI-S was used to define a stable subset of patients to assess test-retest reliability, and correlations with EORTC scales were used to assess convergent and discriminant validity. Meaningful change thresholds were estimated using distribution-based and PGI-S anchor-based analyses.
RESULTS: The SKINDEX-16 exhibited good internal consistency (alpha = 0.95) and test-retest reliability (r = 0.83). Correlations between SKINDEX scores and EORTC scale scores conformed to expectations. Estimated thresholds for meaningful improvement and worsening ranged from 9-14 points in the total score.
CONCLUSIONS: This study is the first to examine psychometric properties of the SKINDEX-16 in the context of dermatologic side effects of cancer treatment. Results from this study support the validity of the SKINDEX-16 in this context of use and aid the interpretation of clinically meaningful change in scores over time.
METHODS: The study included data from 199 adults (median age = 63 years) in the Phase 2 COCOON randomized trial, which evaluated the impact of enhanced versus standard dermatologic management on adverse events among patients with EGFR-mutated NSCLC treated with amivantamab and lazertinib. Participants completed the SKINDEX-16, EORTC QLQ-C30, and a single-item patient global impression of skin symptom severity (PGI-S) at study baseline and every two weeks for the first 12 weeks post-baseline. The PGI-S was used to define a stable subset of patients to assess test-retest reliability, and correlations with EORTC scales were used to assess convergent and discriminant validity. Meaningful change thresholds were estimated using distribution-based and PGI-S anchor-based analyses.
RESULTS: The SKINDEX-16 exhibited good internal consistency (alpha = 0.95) and test-retest reliability (r = 0.83). Correlations between SKINDEX scores and EORTC scale scores conformed to expectations. Estimated thresholds for meaningful improvement and worsening ranged from 9-14 points in the total score.
CONCLUSIONS: This study is the first to examine psychometric properties of the SKINDEX-16 in the context of dermatologic side effects of cancer treatment. Results from this study support the validity of the SKINDEX-16 in this context of use and aid the interpretation of clinically meaningful change in scores over time.
Conference/Value in Health Info
2026-05, ISPOR 2026, Philadelphia, PA, USA
Value in Health, Volume 29, Issue S6
Code
PCR95
Topic
Patient-Centered Research
Topic Subcategory
Instrument Development, Validation, & Translation, Patient-reported Outcomes & Quality of Life Outcomes
Disease
SDC: Oncology