Table 1 Cognitive Interview Prompts and Response Scales

1. Describe the question to me in your own words.

(Item interpretation, understanding)

2. What aspects of the item are confusing?

(Item interpretation, understanding)

3. What do you think of this item?

(Item Quality)

4. How would you go about selecting your answer?

(Response generation)

5. What time frame did you base your answer on?

(Recall time frame)

6. How would you change this item to improve it?

(Patient generated improvements)

7. Is your knee joint relevant to the way you would respond to this item?

(Relevance of the knee to response)

 Highly Relevant

My knee could affect the way I answer this question.

 Somewhat Relevant

My knee could possibly affect the way I answer this question.

 Not Relevant

My knee would not affect the way I answer this question.

Is this question important to you?

(Importance of the item to the individual)

 Highly Important

This question is highly important to understanding how my knee affects my function.

 Somewhat Important

This question is somewhat important to understanding how my knee affects my function.

 Not Important

This question is not at all important to understanding how my knee affects my function.