Table 1

Anchor items used to determine the MIC, PASS and TF criteria in a previous study7 9

MIC anchor questionsAnchor response options
KOOS pain: How is your knee pain now compared with prior to your operation?
  • Better, an important improvement

  • Somewhat better, but enough to be an important improvement

  • Very small change, not enough to be an important improvement

  • About the same

  • Very small change, not enough to be an important deterioration

  • Somewhat worse, but enough to be an important deterioration

  • Worse, an important deterioration

KOOS symptoms: How are the other symptoms in your knee now compared with prior to your operation (swelling, stiffness, decreased range of motion)?
KOOS ADL: How is your ability to perform daily activities now, compared with prior to your operation (sitting, standing, walking, stairs, putting on/taking off socks, household work)?
KOOS sport/recreation: How is your ability to perform sport and recreational activities now, compared with prior to your operation (running, jumping, squatting, kneeling, twisting on loaded knee)?
KOOS QOL: How is your quality of life in relation to your knee now, compared with prior to your operation (trust in knee, lifestyle, how often you think of your knee, and so on)?
PASS and TF anchor questions Anchor response options
PASS: Considering your knee function, do you feel that your current state is satisfactory? With knee function, you should take into account all activities during your daily life, sport and recreational activities, your level of pain and other symptoms, and also your knee-related quality of life.
  • Yes

  • No

TF: If you answered ‘No’ to the previous question, would you consider your current state as being so unsatisfactory that you think the treatment has failed?
  • Yes

  • No

  • ADL, activities of daily living; KOOS, Knee injury and Osteoarthritis Outcome Score; MIC, minimal important change; PASS, patient acceptable symptom state; QOL, quality of life; TF, treatment failure.