Table 2 Characteristics of study participants

 Age, years

59.9 (9.1)

62.7 (8.9)

< 0.001

 Female, n (%)

1224 (57.7)

1311 (58.3)

0.71

 Body mass index, kg/m²

27.6 (4.5)

29.8 (4.8)

< 0.001

Kellgren-Lawrence grade, n (%)

–

 0

1432 (67.5)

–

 1

688 (32.5)

–

 2

–

1173 (52.2)

 3

–

787 (35.0)

 4

–

289 (12.8)

WOMAC pain score (range 0–20)

1.9 (2.7)

3.7 (3.8)

< 0.001

WOMAC pain score > 5, n (%)

307 (14.5)

760 (33.8)

< 0.001

 Knee pain pattern over 1 year, n (%)

< 0.001

  No knee pain at both baseline and 1 year

1669 (80.5)

1265 (57.8)

  Fluctuating knee pain (pain at either baseline or 1 year)

274 (13.2)

464 (21.2)

  Persistent knee pain (pain at both baseline and 1 year)

131 (6.3)

459 (21.0)

 Medial compartment

0.68 (1.13)

1.36 (1.95)

< 0.001

 Lateral compartment

0.73 (1.03)

1.21 (1.41)

< 0.001

Incidence of ROA over 4 years, n (%)

165 (9.6)

–

–

Progression of ROA over 4 years, n (%)

–

272 (17.8)

–