The Western Ontario and McMaster Universities Osteoarthritis, Lequesne Algofunctional index, Arthritis Impact Measurement Scale-short form, and Visual Analogue Scale in patients with knee osteoarthritis: responsiveness and minimal clinically important differences

Abstract

Purpose

The goal of this study was to see whether the Western Ontario and McMaster Universities Osteoarthritis index (WOMAC), Lequesne Algofunctional index and the Arthritis Impact Measurement Scale-short form (AIMS2-SF) could changes after physiotherapy interventions (i.e., responsiveness) and to determine Minimal Clinically Important Difference (MCID) in the performance of the people with knee osteoarthritis.

Materials and methods

A convenient sample of 116 people with knee osteoarthritis completed the tools at baseline and then again after 10 sessions physiotherapy intervention. Two techniques were used to determine responsiveness: The receiver operating characteristics (ROC) method and the correlation analysis.

Result

All of the tools showed the AUC of greater than 0.70 (AUC ranges = 0.72 − 0.83). For the WOMAC, Lequesne Algofunctional index, AIMS2-SF and VAS-pain, optimal cutoff points were 12.5, 2.75, 4.5 and 2.5 points, respectively. The gamma correlation between WOMAC, Lequesne Algofunctional index, AIMS2-SF, VAS-pain, and Global Rating Change (GRC) scores was 0.55, 0.52, 0.40, and 0.46, respectively.

Conclusion

In people with knee osteoarthritis, the WOMAC has the maximum responsiveness to clinical changes. The MCID values identify in this study will aid in determining whether or not an individual with knee osteoarthritis has undergone a true improvement since receiving physiotherapy.

IMPLICATIONS FOR REHABILITATION

• The results of this study provide valuable information regarding to the ability of outcome measures to detect treatment effects in patients with knee osteoarthritis.

• The WOMAC questionnaire is a responsive tool to measure the changes in functional activity due to physiotherapy intervention in patients with knee osteoarthritis.

• A patient with knee osteoarthritis had to change at least 12.5 scores on the WOMAC to be judged as having clinically changed.

Keywords:

• Responsiveness
• knee osteoarthritis
• WOMAC
• lequesne algofunctional
• AIMS2-SF

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This study is part of the MSc thesis of the first author. Special thanks to Ahvaz Jundishapur University of Medical Sciences for financial support [Grant number: PHT-9527]. This study received approval from the local ethics committee “Ahvaz Jundishapur University of Medical Sciences” (approval number IR.AJUMS.REC.1395-766].