How to use WOMAC and KOOS

Once you know how to use WOMAC it will become easy, fast and reliable. You can score for one joint or for your whole body. Whatever you choose always answer the same way. Think about how this joint has affected you over the last 48 Hrs.

There are 24 questions. If you want to be able to compare how severe your osteoarthritis is today it is important to take your time and answer every question. If you miss a question it may give you an incorrect lower value. Having said that there are in fact two activities that you may never do. Question 12 “Bending to the floor” and question 20 “Getting in or out of the bath”. If you are unable to bend to the floor answer ‘extreme’. If you can but choose not to because you cannot get back up again then choose the answer that you think best describes your degree of difficulty. Many people do not own a bath and leave this question blank.

A low score is good and a high score means you have been more disabled over the last 48Hrs. Your score will be different each time you answer the questions because we do have good days and bad days.

We can convert your score to a percentage. It may be easier to see an improvement or deterioration as a percentage change can have more meaning to us. This is particularly so if we are trying a new treatment or intervention and we want to know ‘Is it worth the time, cost and effort?’ You can review these activities in “Treatment of osteoarthritis pain

Think about how your joint has affected or limited you over the last 48Hrs.

How to use KOOS

WOMAC is the original questionnaire and focuses on the long term consequences of Osteoarthritis. Because it has been around for longer it has been more extensively evaluated. KOOS was developed as an extension of WOMAC hoping to evaluate short and long term symptoms and function. Trauma to the knee (Sport, MVA, falls, etc) damages multiple tissues (Ligaments, menisci, cartilage, bone, etc) and often leads to the development of Osteoarthritis. We need to measure damage after trauma and record the changes in symptoms and function over time. This allows us to monitor the acute injury in physically active and younger patients and the chronic changes as those patients age and develop Osteoarthritis. Ewa Roos lead the team that developed the KOOS in Sweden and in the USA in 1995.

How important are these questions?

In the defining studies Roos and Lohmander reported that 90% of patients reported that improvement in the four subscales 

  • Pain, 
  • Symptoms, 
  • Activities of Daily Living, 
  • Knee related Quality of Life were . 

were extremely important when deciding whether to have surgery or not

51% reported that improvements in subscale Sport and Recreation Function such as 

  • squatting
  • kneeling, 
  • jumping, 
  • twisting and 
  • running

were extremely important when deciding whether to have surgery or not.

So what does that mean for you?

Just as these questions are important for a lot of people some or all of them may be important for you. As you read each question only you can decide what is really important for you. If you have the time and patience you can use every question. If they are not all important to you then create a short list of those questions that are most important to you. This is your list for reporting to yourself. It is most likely that your treating practitioner will want a full list for long term reference and a short list for tracking short term changes. Learning how to use WOMAC properly allows you to see how to design a short version customized to yourself.

What other measures are there?

Just as the WOMAC was modified to measure long term changes following joint injury (KOOS), questions aimed at Foot and Ankle problems have been included in (FAOS) and questions related to the hip have given us (HOOS).

Can I make my own Measure?

  • Absolutely yes. WOMAC uses the Likert scale. The Likert scale is very widely used in surveys because it takes qualitative symptoms such as Pain (Weak, moderate, Strong) and converts them to a number (Quantitative). This allows us to express a change in pain in a way that the people around us find easier to understand. A Likert item is one question and a scale is more than 8 questions grouped together.
  • Results can be expressed as the total number of all questions.
  • The average of all the questions.
  • Or as a percentage of the highest score possible.

Write down everything that bothers you. Have a score for how often it occurs (Always present, Several times a day, once a day, once a week, twice a week, once a moth, once a year, never). Have a score for severity. (Bedbound, Wheelchair, walking aid – frame, cane, limping, walking, running, etc) As you use your new measure you will start to see what are good questions and how to improve or eliminate questions.

WOMAC assigns a score of 0 to no symptom up to 4 for extreme symptoms. KOOS goes in the opposite direction. It assigns 0 to extreme symptoms up to 4 for no symptom. So a low score in WOMAC means you are better and in KOOS means you are worse.

Why should I learn how to use WOMAC?

As you look back at the data you have collected you will start to see patterns and recognize those things that affect you, better and worse, and you will have an easy measure of how important things have been. ‘If I do this how long does it take me to recover?’ ‘How much did it set me back?’ How much improvement did I get by cutting out white bread. Do I also need to reduce other white flour products? The importance of the changes you make starts to be easier to see.

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