Is a "false-positive" clinical diagnosis of knee osteoarthritis just the early diagnosis of pre-radiographic disease?

Abstract

In routine practice, diagnosis of knee osteoarthritis (OA) currently relies on the combination of conventional risk factors and the presence of cardinal signs and symptoms. However, their role in early diagnosis has received little attention compared with biomarker research. Using data from 122 adults ages ≥50 years with knee pain but no definite radiographic OA, we tested whether the clinical diagnostic probability of OA, based on risk factors, signs, and symptoms, was associated with subsequent incidence of radiographic OA 3 years later. Clinical diagnostic probability performed only modestly in discriminating incident radiographic knee OA (area under the receiver operating characteristic curve = 0.59, 95% confidence interval 0.49-0.70). Improving the measurement of conventional markers and using study designs that test the ability of new biomarkers to add to or replace conventional markers are priorities for research in the early diagnosis of OA.