Table 1

 Descriptive statistics of the study population

All (n = 2834)Men (n = 1615)Women (n = 1219)
*Categories not mutually exclusive due to multiple joints affected.
†Body mass index = weight in kilograms/(height in metres)2.
Mean age (SD)61.8 (9.3)61.1 (9.3)62.5 (9.3)
Mean age at start of symptoms (SD)54.4 (9.1)54.2 (8.9)54.7 (9.3)
Joint affected (%)*
    Knee59.363.953.3
    Hip31.835.427.0
    Hand27.415.842.7
    ⩾2 of above8.85.520.6
    Missing13.913.514.9
Bilateral OA (%)
    Knee43.141.146.8
    Hip26.624.331.2
    Hand65.655.170.9
Professional status
    Active41.345.536.2
    Retired54.452.656.8
    Unemployed4.31.97.0
History of trauma in joint affected by osteoarthritis24.028.018.7
BMI†⩾2560.770.648.7