Our aim was to estimate the proportion of knee and hip OA patients showing worsening at 2 years, and to examine the additional predictive value of failure of optimised non-surgical treatment during 3 months for worsening at 2 years.
Data of patients participating in the longitudinal CONTROL-PRO study (patients fulfilling clinical ACR criteria for knee or hip OA) were used. Measurements of pain, functioning and patient global assessments were performed at baseline, 3 months and 2 years. Worsening at 2 years was defined as fulfilling the recently validated clinical worsening criteria for knee and hip OA, or total joint replacement (TJR). Logistic regression was performed with worsening at 2 years as the dependent variable.
The 297 included patients were predominantly women (66%) with a mean age of 55 years. At 2 years, 61% showed worsening (knee 59%; hip 71%) and 24% had undergone a TJR (knee 19%; hip 51%). Clinical worsening at 3 months appeared to be a clear independent predictor for worsening at 2 years (OR 2.8 95% CI 1.5-5.2) with a moderate discriminative ability (AUC 0.68 95% CI 0.57-0.70). Similar results were obtained when only TJR at 2 years was used as the outcome measure (OR 4.1 95% CI 2.0-8.4) with good AUC (0.82 95% CI 0.76-0.87).
Our findings suggest that re-assessment of symptoms after optimised non-surgical treatment could be meaningful in clinical decision making for TJR. Furthermore, this information could be used to identify subgroups of patients potentially eligible for novel and advanced treatment options.