Is self-reported improvement in osteoarthritis pain and disability reflected in objective measures?

Abstract

To determine if self-reported improvements in pain and function correlate with improvement in objective measures of disease in osteoarthritis (OA). Individuals with disabling hip/knee OA were assessed 7 years apart by questionnaire [sociodemographics, body mass index, and Western Ontario and McMaster University Osteoarthritis Index (WOMAC) scores] and physical [range of motion (ROM), disease activity based on joint stress pain, erythema, warmth, effusion] and radiographic examination of the hips and knees (Kellgren-Lawrence grade). Changes over time were expressed as improved, unchanged, or worse based on a priori criteria. Of 69 eligible patients, 43 (64%) with a mean age of 76.3 years participated; 77% were female. For WOMAC scores, 25% and 19% reported improved pain and function, respectively. For joint ROM, disease activity, and radiographic grade, 0% to 30% of participants were improved. However, improvements in WOMAC scores were not associated with improvements in any of the other measures (r < 0.24 for all). One-quarter of participants reported significant improvements in WOMAC pain and disability after 7 years' followup. However, these improvements were not associated with similar improvements in joint ROM, disease activity, or radiographic grade. Greater understanding of the determinants of self-reported improvements in arthritis status, in particular the role of adaptation, is warranted.