OBJECTIVES

:

To explore patient and physician preferences and comparability of responses across 0-100mm Visual Analogue Scale (VAS), 0-10 Numerical Rating Scale (NRS), and 4-point Likert scales (LS) used in clinical outcome assessments (COAs) in Sjögren’s.

METHODS

: As part of a larger qualitative cognitive interview study, adult US patients with Sjögren’s (N=12) reviewed responses scales assessing symptom severity: VAS and NRS([anchors: ‘no symptoms’ to ‘severe symptoms’]) and LS (None/Mild/Moderate/Severe). Expert Sjögren’s physicians in the US, UK, and Germany (N=10) also participated and reviewed response scales assessing disease activity: VAS/NRS (anchors ‘no disease activity’ to ‘maximal disease activity’), and LS (Inactive disease/low/moderate/high disease activity). Participants ranked the scales by preference and also marked the equivalent of each LS response on the corresponding NRS and VAS to explore between-scale comparability of responses.

RESULTS

: Most patients (6/12) preferred the NRS scale, followed by VAS and LS (each 3/12). Most physicians (6/10) also preferred NRS, followed by VAS (3/10) and LS (1/10). Reasons for preference typically related to ease of use.

Patients reported ‘Severe’ on the LS as 8-10 (NRS) and 80mm-100mm (VAS). ‘Moderate’ ranged between 3-9 (NRS) and 37mm-77mm (VAS). ‘Mild’ ranged between 1-6 (NRS) and 11mm-53mm (VAS). ‘None’ ranged between 0-4 on the NRS and 0mm-52mm on the VAS.

Physicians rated ‘High disease activity’ on the LS as ranging between 7-10 (NRS) and 72mm-100mm (VAS). ‘Moderate disease activity’ ranged between 4-7 (NRS) and 35mm-55mm (VAS). ‘Low disease activity’ ranged between 1-5 (NRS) and 5mm-28mm (VAS). ‘Inactive’ was consistently selected as 0 on the NRS and 0mm on the VAS.

CONCLUSIONS

: NRS was selected most frequently as the preferred scale by both patients and physicians. Participant’s responses were largely concordant across VAS, NRS, and LS, with only minor overlap in category interpretation. Future research is required to further confirm the comparability of between-scale responses in a larger sample.