The Oxford Knee Score (OKS)
The Oxford Knee Score (OKS) is a patient reported outcome measure developed in 1996 to specifically evaluate knee replacement outcomes. Since then, its scope has broadened to include its use in other disorders of the joint and in surgical treatments not limited to arthroplasty.
The Oxford Knee Score has undergone rigorous assessments of reliability, validity and responsiveness in many studies. The OKS has been used in trials, audits and played a key role in national joint replacement registries, including those in England, New Zealand and Sweden.
The Oxford Knee Score continues to enjoy widespread popularity as a PRO measure. The extensive use of this measure resulted in many modified versions of the survey being utilized for different purposes, which inevitably led to confusion. In 2007, the original developers of the measure released a statement paper to help address this issue and sought to clarify the correct usage and scoring methodology of the Oxford Knee Score.
The OKS questionnaire consists of twelve questions that cover function and pain of the knee. Each question is scored from 0 to 4 (0 being the worst outcome and 4 being the best). The overall score is the sum of all items and can range from 0 to 48, with higher scores corresponding to better outcomes. This simple scoring process is one that authors recommend to be utilized.
The Oxford Knee Score is a well-regarded PRO measure that has proven to be valid and sensitive to clinically important changes over time, specifically in patients undergoing a total joint replacement. The survey is also short, easy to administer and simple to score.
Although the OKS is a short, relatively simple tool it has been noted that some questions may be confusing to patients There are several questions where the extreme response “not at all” can also be wrongly inferred by the patient to mean the opposite of what was intended. This has a drastic impact on the score and decreases the reliability of the measure.
Licensing and Cost
Paid. The Oxford Knee Score requires a license. To learn more, please visit their website: https://process.innovation.ox.ac.uk/clinical/.