The evaluation of pain in patients with knee osteoarthritis: the knee pain scale.

OBJECTIVE

To develop and validate a knee pain scale (KPS) for use with osteoarthritis (OA) of the knee.

METHODS

Patients with documented evidence of knee OA completed the KPS and a test battery including measures of physical functioning, physical performance, and depression. Analyses were conducted to confirm the 4-factor structure of the measure, determine alpha reliabilities, assess the test-retest reliability, and examine the construct validity of the KPS.

RESULTS

Confirmatory factor analysis revealed that the KPS has 4 subscales, including frequency and intensity of pain experienced during both ambulation/climbing and transfer activities. All reliabilities were in excess of 0.80 and the subscales of the KPS shared expected variance with both self-reported and objective indices of dysfunction.

CONCLUSION

The KPS has good psychometric properties for assessing pain experienced in conjunction with the performance of activities of daily living. Although at present it is a research tool, with further study it should prove valuable in clinical practice as well.