Visual Analogue Scale has higher assay sensitivity than WOMAC pain in detecting between-group differences in treatment effects: a meta-epidemiological study

Bruno R da Costa; Pakeezah Saadat; Reto Basciani; Arnav Agarwal; Bradley C Johnston; Peter Jüni

doi:10.1016/j.joca.2020.10.004

Visual Analogue Scale has higher assay sensitivity than WOMAC pain in detecting between-group differences in treatment effects: a meta-epidemiological study

Osteoarthritis Cartilage. 2021 Mar;29(3):304-312. doi: 10.1016/j.joca.2020.10.004. Epub 2020 Nov 30.

Authors

Bruno R da Costa¹, Pakeezah Saadat², Reto Basciani³, Arnav Agarwal⁴, Bradley C Johnston⁵, Peter Jüni⁶

Affiliations

¹ Applied Health Research Centre (AHRC), Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, ON, Canada; Institute of Primary Health Care (BIHAM), University of Bern, Bern, Switzerland; Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, ON, Canada. Electronic address: bruno.dacosta@utoronto.ca.
² Applied Health Research Centre (AHRC), Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, ON, Canada; Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, ON, Canada. Electronic address: pakeezah.saadat@mail.utoronto.ca.
³ Institute of Primary Health Care (BIHAM), University of Bern, Bern, Switzerland; Department of Anesthesiology, Cantonal Hospital Aarau, Aarau, Switzerland. Electronic address: reto.basciani@ksa.ch.
⁴ Applied Health Research Centre (AHRC), Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, ON, Canada; Department of Medicine, University of Toronto, Toronto, ON, Canada. Electronic address: arnav.agarwal@mail.utoronto.ca.
⁵ Department of Community Health and Epidemiology, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada; Department of Health Research Methods, Evidence and Impact, McMaster University, Hamilton, ON, Canada; Department of Nutrition, Texas A&M University, College Station, TX, 77845, USA. Electronic address: bradley.johnston@tamu.edu.
⁶ Applied Health Research Centre (AHRC), Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, ON, Canada; Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, ON, Canada; Department of Medicine, University of Toronto, Toronto, ON, Canada. Electronic address: peter.juni@utoronto.ca.

PMID: 33271331
DOI: 10.1016/j.joca.2020.10.004

Abstract

Objective: To compare assay sensitivity of the Visual Analogue Scale (VAS) for global osteoarthritis pain and the Western Ontario and McMaster University (WOMAC) pain subscale, and the associated between-trial heterogeneity in effect sizes (ES).

Design: We included trials with placebo, sham or non-intervention control that included at least 100 patients with hip or knee osteoarthritis per arm, reporting both VAS and WOMAC pain scores. ES were calculated as between-group difference in means divided by the pooled standard deviation and compared using a paired t-test. ES and τ² as a measure of between-trial heterogeneity were combined using random-effects meta-regression with robust variance estimation to account for the correlation of data within trials and meta-analyses.

Results: Twenty-eight trials with 44 randomized comparisons were included. In 28 comparisons (64%), ES from VAS favoured the intervention more than those from WOMAC pain (P = 0.003). Twenty-six p-values (59%) were smaller according to VAS (P = 0.008). The 44 comparisons contributed to 12 meta-analyses. Eleven meta-analyses (92%) showed larger benefits of interventions according to VAS, with a combined overall difference in ES of -0.08 (95% CI -0.14 to -0.02). τ² was similar for VAS and WOMAC pain (difference in τ², -0.003, 95% CI -0.009 to 0.004).

Conclusion: The VAS for global pain had slightly higher assay sensitivity at trial and meta-analysis levels than the WOMAC pain subscale without relevant increase in between-trial heterogeneity.

Keywords: Assay sensitivity; Osteoarthritis; VAS pain; WOMAC pain.

Publication types

Meta-Analysis
Research Support, Non-U.S. Gov't
Systematic Review

MeSH terms

Acupuncture Therapy
Analgesics / therapeutic use
Anti-Inflammatory Agents, Non-Steroidal / therapeutic use
Humans
Osteoarthritis, Hip / physiopathology
Osteoarthritis, Hip / therapy*
Osteoarthritis, Knee / physiopathology
Osteoarthritis, Knee / therapy*
Pain Measurement / methods*
Physical Therapy Modalities
Randomized Controlled Trials as Topic
Surveys and Questionnaires
Treatment Outcome
Viscosupplements / therapeutic use

Substances

Analgesics
Anti-Inflammatory Agents, Non-Steroidal
Viscosupplements