Properties of the patient administered questionnaires: new scales measuring physical and psychological symptoms of hip and knee disorders.

Abstract

The Patient Administered Questionnaires (PAQ) incorporate physical and psychological symptoms into one scale and permit more comprehensive self-reports for hip and knee disorders. We tested the psychometric properties of the PAQ-Hip and PAQ-Knee. Correlations between baseline PAQ-Hip and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) were .39 to .72 (n = 102), .39 to .69 for score change (n = 68 post-total hip arthroplasty), and most κ values > .60 (n = 50). Correlations between baseline PAQ-Knee and WOMAC were .35 to .64 (n = 100), .62 to .79 for score change (n = 43 post-total knee arthroplasty), and most κ values >.60 (n = 51). For both scales, effect sizes were higher than for the WOMAC, and there was modest correlation between physical and psychological questions, indicating these concepts are not completely interchangeable. Thus, the PAQ scales have strong psychometric properties and are unique compared with existing scales by including physical and psychological symptoms.