Comparison between two patient-reported outcome measures for patients with cervical radiculopathy: A think-aloud study

Background: The Cervical Radiculopathy Impact Scale (CRIS) and Patient Specific Functional Scale 2.0 (PSFS 2.0) are patient-reported outcome measures (PROMs) used to assess activity limitations in patients with cervical radiculopathy (CR). This study a) compared the CRIS subscale 3 and the PSFS 2.0 in patients with CR with respect to completeness and patient preference, b) established the correlation between both PROMs in assessing the individual patient's level of functional limitations and c) assessed the frequency of reported functional limitations. Methods: Participants with CR participated in semi-structured, individual, face-to-face interviews as part of a "think-aloud" process; verbalising their thoughts while completing both PROMs. Sessions were digitally recorded and transcribed verbatim for analysis. Results: Twenty-two patients were recruited. The most frequently reported functional limitation on the CRIS was: 'working at a computer' (n = 17) and overhead activities' (n = 10) for the PSFS 2.0. There was significant moderate positive correlation between the scores on the PSFS 2.0 and the CRIS (Spearman's r = 0.55, n = 22 p = .008). Most patients (n = 18; 82%) preferred the ability to present their own individual functional limitations of the PSFS 2.0. Eleven participants (50%) preferred the 11-point scale of the PSFS 2.0 over the 5-point Likert scale scoring option of the CRIS. Conclusion: Both easy to complete PROMs capture functional limitations in patients with CR. Most patients prefer the PSFS 2.0 over the CRIS. The wording and layout of both PROMs need refinement to enhance user-friendliness and avoid misinterpretation.