The 4 scale types of patient-reported outcome measures (PROMs) appeared to be equally valid to assess pain, fatigue, experienced disease activity, and general well-being in persons with rheumatoid arthritis (RA). This according to a recent study that assessed the construct validity and reproducibility of 4 types of PROMs (numerical rating scale [NRS], visual analogue scale [VAS], verbal rating scale [VRS], and Likert scale.) Patients with stable RA and no change in pain medication or steroid medication (n=211) were asked to complete a questionnaire directly following, and 5 days after, their outpatient visit. Researchers found:
- There were no differences regarding construct validity between the different PROM scale types.
- Regarding reproducibility, VAS and NRS scored better in the domains pain and experienced disease activity.
- Patients chose NRS as preferred measurement method, with the VAS in second place.
In combination with other practical advantages of NRS over VAS, investigators advise the NRS as the preferred scale type for PROMs.
Renskers L, van Uden RJJC, Huis AMP, Rongen SAA, Teerenstra S, van Riel PLCM. Comparison of the construct validity and reproducibility of four different types of patient-reported outcome measures (PROMs) in patients with rheumatoid arthritis. [Published online ahead of print September 12, 2018]. Clin Rheumatol. doi:10.1007/s10067-018-4285-x.
The authors of this study examined 4 different methods for measuring responses of patients with rheumatoid arthritis (RA) to questions on patient-reported outcome measures (PROMs) questionnaires. 4 different scales were used to quantify patients’ assessment of their pain, fatigue, disease activity, and general well-being: numerical rating scale, visual analogue scale, verbal rating scale, and Likert scale. Each question was followed by the 4 scales, and patients were asked which scale best described their situation. Statistical analysis showed that all 4 scales were equally valid for measuring patient status, but patients preferred the numerical rating scale and it was also the most reliable for measuring the pain and disease activity. —Harold E. Paulus, M.D.; Emeritus Professor; University of California, Los Angeles; Division of Rheumatology.