Reliability of the electronic patient reported outcome measures for assessing xerostomia, dysphagia and quality of life in Spanish patients with head and neck cancer: a randomised crossover design.

Purpose: To analyse reliability in terms of concordance (agreement) and equivalence of the Patient Reported Outcome Measures (PROM) with an electronic modality (ePROM) of the recognised questionnaires assessing of xerostomia, dysphagia and quality of life (QoL) in Spanish patients with head and neck cancer (HNC). We hypothesised notable reliability and equivalence between the two modalities.

Methods: A total of 24 patients (median age 63.00 years, undergone radiotherapy, either alone or in combination with surgery and/or chemotherapy, and suffering xerostomia) were randomised to either paper-based (PROM) or ePROM in a two-arm crossover design with a within-subject comparison of the two modalities (washout period 90 min). Outcome measures of interest were xerostomia: severity itself (Xerostomia Inventory, XI), perceived xerostomia (visual analogue scale, VAS), regional oral dryness (Regional Oral Dryness Inventory, RODI) and dry mouth/sticky saliva (specific head and neck module European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Head and Neck Module, EORTC QLQ-H&N35 and updated EORTC QLQ-H&N43); dysphagia: swallowing burden (Eating Assessment Tool-10, EAT-10) and swallowing (EORTC QLQ-H&N35 and EORTC QLQ-H&N43); and QoL: global health (EORTC QLQ-Core 30, EORTC QLQ-C30). Data concerning the concordance between modalities was evaluated using Spearman correlation coefficients, intraclass correlation coefficients (ICCs) and Bland Altman plots with limits of agreement. In addition, a two one-sided test to check equivalence with clinical importance changes. Finally, 1-week time span separated test and retest of ePROM (only electronic modality) using Wilcoxon test and ICCs.

Results: There was excellent concordance (PROM versus ePROM 0.79-0.96) with most differences fell within the limits of agreement. The equivalence analysis showed that the difference between both modalities was not more than a tolerably small amount (P < 0.05), except for dysphagia and QoL. Analysis over time exhibited from good to excellent (0.81-0.93) test-retest stability for the majority of outcome measures.

Conclusion: The newly developed ePROMs embedded into LAXER application have showed high level of reliability that supports their implementation in clinical practice, offering a convenient and efficient alternative to paper-based questionnaires. This study shows that electronic adaptations are possible despite the challenging older target population.

Trial Registration: The study is part of the LAXER study (2021-11-04 / ClinicalTrials.gov: NCT05106608).