Table 2.

Case‐mix variable domains and definitions included in the Standard Set

Category and case‐mix factor domain	Case‐mix factor definition	Agreementa
Demographics
Age	Date of birth	100
Sex	Sex at birth	100
Education level	Please indicate the highest level of schooling completed: none, primary, secondary, tertiary (university or equivalent)	88
Baseline clinical status
Joint‐specific history	Please indicate if the patient has a history or findings of any of the following for each hip and knee: none; trauma or ligmental injury; congenital or developmental disorders; other joint disorders including but not limited to osteonecrosis, inflammatory arthritis, gouty arthritis, septic arthritis, and Paget's disease of the bone	84
Joint‐specific surgical history	Please indicate the type of surgery the patient has on each hip and knee: none; joint replacement; osteotomy; osteosynthesis/facture surgery; ligament reconstruction (knee only); other arthroscopic procedures	82
Other case‐mix factors
Living status	Which statement best describes your living arrangement? I live with partner/spouse/family/friends; I live alone; I live in a nursing home/hospital/other long‐term care home; other	100
Body mass index	Calculated from patient‐reported height and weight	88
Physical activity	In a typical week, how much time do you spend doing physical activity? Physical activity is any activity that makes you breathe hard, feel warm, and feel your heart beat faster. Examples of physical activity are walking, bicycling, and dancing and also housecleaning and gardening. None; about 30 minutes; about 1 hour; about 2 hours; more than 2 hours	88
Tobacco smoking status	Do you smoke? No/yes	88
Comorbid conditions	Have you been told by a doctor that you have any of the following? (Tick all that apply to you) Heart disease (for example angina, heart attack, or heart failure); high blood pressure; problems caused by a stroke; leg pain when walking due to poor circulation; lung disease (for example asthma, chronic bronchitis, or emphysema); diabetes mellitus; kidney disease; diseases of the nervous system (for example Parkinson's disease or multiple sclerosis); liver disease; cancer (within the last 5 years); depression; arthritis in your back or other condition affecting your spine; rheumatoid arthritis or another kind of arthritis in addition to osteoarthritis	92

^aPercentage agreement among survey respondents.