Finding ways to measure change in patients’ level of satisfaction, function, stiffness, disability, or other symptoms like pain and swelling is a challenge. Each diagnosis has specific differences. Even within one single diagnostic category (like knee osteoarthritis), there can be a range from acute to chronic, mild-to-severe, and symptomatic or asymptomatic (X-ray findings of arthritis but no symptoms).
Current standard of practice is to use the Western Ontario and McMaster Universities Osteoarthritis Index, commonly referred to as WOMAC. This is a reliable and valid measure of self-reported change for patients with hip or knee osteoarthritis. As you have seen from using it, the survey has 24 questions that are broken into three categories.
The first category measures pain during activities, the second evaluates change in stiffness, and the third looks at physical function. Activities such as standing up from a sitting position, walking, climbing up and down stairs, or putting socks on are included.
Studies consistently show that the WOMAC is responsive to change in patients with hip or osteoarthritis and that’s why it is used most often.
There are two other tests that have also been shown to be responsive (i.e., measures change before and after treatment). These include the Knee Outcome Survey (KOS) and the Lower Extremity Functional Scale (LEFS). The KOS assesses limitations caused by pain, swelling, and joint instability. The LEFS looks more at the degree-of-difficulty someone has performing specific tasks during activities of daily living.
The best way to get a handle on which one to use in your practice might be to use all three with specific groups of patients. See which one is easiest and least time consuming, while still giving you the information you are looking for.