Background
Methods
Design
Stage I: TOF pilot study
Knee/hip pain vs. knee/hip problems
Leisure time physical activity
Family history of OA
Stage II: Second questionnaire on knee/hip-relevant risk factors
Knee alignment and foot rotation
Occupational physical exposures
Statistical analysis
Results
Cohort recruitment
Stage I: TOF pilot study
Source population | Invited to consent | Consented to participate in TOF pilot study | Invited to respond to TOF survey | TOF survey respondents | TOF survey respondents with knee/hip problems a | Invited to respond to second questionnaire | Second questionnaire respondents | |
---|---|---|---|---|---|---|---|---|
N
| 9400 | 8814 | 3587 | 3557 | 2661 | 1152 | 1126 | 867 |
Age (years) | ||||||||
29–39 | 2633 (28) | 2488 (28) | 669 (19) | 665 (19) | 430 (16) | 165 (14) | 159 (14) | 116 (13) |
40–49 | 3179 (34) | 2989 (34) | 1147 (32) | 1136 (32) | 811 (30) | 326 (28) | 322 (29) | 236 (27) |
50–59 | 3588 (38) | 3337 (38) | 1771 (49) | 1756 (49) | 1420 (53) | 661 (57) | 645 (57) | 515 (59) |
Sex | ||||||||
Women | 4644 (49) | 4379 (50) | 1982 (55) | 1964 (55) | 1497 (56) | 638 (55) | 629 (56) | 476 (55) |
Men | 4756 (51) | 4435 (50) | 1605 (45) | 1593 (45) | 1164 (44) | 514 (45) | 497 (44) | 391 (45) |
Persistent knee/hip pain | 729 (27) | 729 (63) | 714 (63) | 561 (65) | ||||
BMIb | ||||||||
Normal/underweight | 1102 (41) | 420 (36) | 409 (36) | 310 (36) | ||||
Overweight | 1001 (38) | 444 (39) | 433 (38) | 335 (39) | ||||
Obesity | 558 (21) | 288 (25) | 284 (25) | 222 (26) | ||||
Leisure time physical activity | ||||||||
High intensity activities | 66 (2) | 26 (2) | 23 (2) | 14 (2) | ||||
Moderate intensity activities | 763 (29) | 332 (29) | 324 (29) | 253 (29) | ||||
Low intensity activities | 1448 (54) | 626 (54) | 615 (55) | 484 (56) | ||||
Sedentary | 384 (14) | 168 (15) | 164 (15) | 116 (13) | ||||
Previous knee/hip injury | 737 (28) | 737 (64) | 718 (64) | 559 (64) | ||||
Previous knee/hip surgery | 395 (15) | 395 (34) | 388 (34) | 305 (35) | ||||
Family history of osteoarthritis | ||||||||
No | 999 (38) | 304 (26) | 296 (26) | 222 (26) | ||||
I don’t know | 494 (19) | 217 (19) | 215 (19) | 168 (19) | ||||
Yes | 1168 (44) | 631 (55) | 615 (55) | 477 (55) |
Stage II: Second questionnaire on hip/knee-relevant risk factors
Knee pain
Women | Men | |||
---|---|---|---|---|
Knee/hip pain | No knee/hip pain | Knee/hip pain | No knee/hip pain | |
29–39 years | 54 (22) | 196 (78) | 41 (23) | 139 (77) |
BMI (kg/m2), mean (SD) | 27.4 (6.3) | 26.4 (6.3) | 26.4 (4.8) | 26.2 (3.9) |
Leisure time physical activity | ||||
High intensity activities | 1 (2) | 6 (3) | 2 (5) | 12 (9) |
Moderate intensity activities | 10 (19) | 43 (22) | 14 (34) | 43 (31) |
Low intensity activities | 29 (54) | 114 (58) | 17 (41) | 57 (41) |
Sedentary | 14 (26) | 33 (17) | 8 (20) | 27 (19) |
Previous knee/hip injury | 27 (50) | 32 (16) | 21 (51) | 34 (24) |
Previous knee/hip surgery | 11 (20) | 17 (9) | 10 (24) | 14 (10) |
Family history of osteoarthritis | ||||
No | 6 (11) | 72 (37) | 13 (32) | 58 (42) |
I don’t know | 12 (22) | 38 (19) | 9 (22) | 30 (22) |
Yes | 36 (67) | 86 (44) | 19 (46) | 51 (37) |
40–49 years | 130 (28) | 331 (72) | 69 (20) | 281 (80) |
BMI (kg/m2), mean (SD) | 29.1 (7.6) | 26.1 (5.4) | 28.5 (4.8) | 27.0 (4.7) |
Leisure time physical activity | ||||
High intensity activities | 2 (2) | 6 (2) | 1 (1) | 9 (3) |
Moderate intensity activities | 34 (26) | 94 (28) | 24 (35) | 123 (44) |
Low intensity activities | 67 (52) | 184 (56) | 30 (43) | 111 (40) |
Sedentary | 27 (21) | 47 (14) | 14 (20) | 38 (14) |
Previous knee/hip injury | 61 (47) | 49 (15) | 35 (51) | 65 (23) |
Previous knee/hip surgery | 24 (18) | 29 (9) | 19 (28) | 45 (16) |
Family history of osteoarthritis | ||||
No | 29 (22) | 128 (39) | 18 (26) | 138 (49) |
I don’t know | 22 (17) | 53 (16) | 15 (22) | 42 (15) |
Yes | 79 (61) | 150 (45) | 36 (52) | 101 (36) |
50–59 years | 245 (31) | 541 (69) | 190 (30) | 444 (70) |
BMI (kg/m2), mean (SD) | 27.6 (5.1) | 26.0 (5.1) | 28.2 (4.7) | 26.9 (4.0) |
Leisure time physical activity | ||||
High intensity activities | 2 (1) | 9 (2) | 2 (1) | 14 (3) |
Moderate intensity activities | 47 (19) | 121 (22) | 57 (30) | 153 (34) |
Low intensity activities | 161 (66) | 351 (65) | 105 (55) | 222 (50) |
Sedentary | 35 (14) | 60 (11) | 26 (14) | 55 (12) |
Previous knee/hip injury | 101 (41) | 105 (19) | 111 (58) | 96 (22) |
Previous knee/hip surgery | 52 (21) | 51 (9) | 60 (32) | 63 (14) |
Family history of osteoarthritis | ||||
No | 50 (20) | 207 (38) | 53 (28) | 227 (51) |
I don’t know | 40 (16) | 101 (19) | 48 (25) | 84 (19) |
Yes | 155 (63) | 233 (43) | 89 (47) | 133 (30) |
Association between OA risk factors and knee/hip pain
Women | Men | |||
---|---|---|---|---|
Univariate RR (95% CI) | Adjusteda RR (95% CI) | Univariate RR (95% CI) | Adjusteda RR (95% CI) | |
29–39 years | n = 250 | n = 180 | ||
BMI (kg/m2) | 1.02 (0.98–1.07) | 1.00 (0.96–1.03) | 1.01 (0.94–1.08) | 1.02 (0.94–1.10) |
Leisure time physical activity | ||||
High and moderate intensity activities | Reference | Reference | Reference | Reference |
Low intensity activities | 1.11 (0.59–2.07) | 1.22 (0.68–2.20) | 1.02 (0.56–1.86) | 1.21 (0.67–2.19) |
Sedentary | 1.62 (0.81–3.24) | 1.48 (0.75–2.93) | 1.01 (0.48–2.14) | 1.28 (0.61–2.68) |
Previous knee/hip injury |
3.24 (2.07–5.06)
|
3.05 (1.84–5.05)
|
2.39 (1.41–4.03)
|
2.34 (1.23–4.47)
|
Previous knee/hip surgery |
2.03 (1.19–3.46)
| 0.85 (0.43–1.71) |
2.10 (1.19–3.70)
| 1.22 (0.57–2.62) |
Family history of osteoarthritis | ||||
No | Reference | Reference | Reference | Reference |
I don’t know |
3.12 (1.25–7.78)
| 2.41 (1.00–5.84) | 1.26 (0.59–2.68) | 1.39 (0.68–2.84) |
Yes |
3.84 (1.70–8.68)
|
2.92 (1.32–6.45)
| 1.48 (0.79–2.77) | 1.31 (0.71–2.44) |
40–49 years | n = 461 | n = 350 | ||
BMI (kg/m2) |
1.07 (1.04–1.11)
|
1.06 (1.02–1.10)
|
1.06 (1.00–1.11)
| 1.04 (0.99–1.10) |
Leisure time physical activity | ||||
High and moderate intensity activities | Reference | Reference | Reference | Reference |
Low intensity activities | 1.01 (0.71–1.43) | 0.85 (0.62–1.15) | 1.34 (0.83–2.16) | 1.32 (0.83–2.09) |
Sedentary | 1.38 (0.91–2.08) | 0.99 (0.66–1.48) | 1.69 (0.95–3.00) | 1.45 (0.80–2.63) |
Previous knee/hip injury |
2.82 (2.15–3.69)
|
2.73 (2.01–3.70)
|
2.57 (1.70–3.88)
|
2.55 (1.57–4.14)
|
Previous knee/hip surgery |
1.74 (1.24–2.44)
| 0.87 (0.56–1.37) |
1.70 (1.08–2.67)
| 0.87 (0.49–1.55) |
Family history of osteoarthritis | ||||
No | Reference | Reference | Reference | Reference |
I don’t know | 1.59 (0.98–2.57) | 1.44 (0.93–2.23) |
2.28 (1.23–4.22)
|
2.01 (1.10–3.68)
|
Yes |
1.87 (1.28–2.71)
|
1.53 (1.09–2.15)
|
2.28 (1.36–3.82)
|
2.00 (1.20–3.29)
|
50–59 years | n = 786 | n = 634 | ||
BMI (kg/m2) |
1.05 (1.02–1.09)
|
1.04 (1.01–1.08)
|
1.07 (1.03–1.12)
|
1.04 (1.00–1.09)
|
Leisure time physical activity | ||||
High and moderate intensity activities | Reference | Reference | Reference | Reference |
Low intensity activities | 1.15 (0.88–1.51) | 1.08 (0.83–1.39) | 1.23 (0.94–1.61) | 1.19 (0.93–1.53) |
Sedentary | 1.35 (0.94–1.92) | 1.11 (0.77–1.59) | 1.23 (0.84–1.81) | 1.18 (0.82–1.69) |
Previous knee/hip injury |
1.97 (1.62–2.41)
|
1.64 (1.31–2.06)
|
2.90 (2.29–3.67)
|
2.61 (1.97–3.45)
|
Previous knee/hip surgery |
1.79 (1.43–2.24)
| 1.20 (0.90–1.60) |
1.92 (1.52–2.42)
| 0.97 (0.72–1.31) |
Family history of osteoarthritis | ||||
No | Reference | Reference | Reference | Reference |
I don’t know |
1.46 (1.02–2.09)
| 1.33 (0.94–1.88) |
1.92 (1.38–2.68)
|
1.57 (1.15–2.14)
|
Yes |
2.05 (1.56–2.71)
|
1.76 (1.34–2.31)
|
2.12 (1.58–2.83)
|
1.63 (1.23–2.15)
|
OA risk factors in people with prolonged persistent knee or hip pain, respectively
Women | Men | |||
---|---|---|---|---|
Knee pain | Hip pain | Knee pain | Hip | |
n = 142a | n = 102a | n = 123 | n = 49 | |
Age (years), mean (SD) | 50.6 (6.6) | 49.2 (7.7) | 49.4 (7.7) | 52.6 (6.7) |
BMI (kg/m2), mean (SD) | 28.4 (6.0) | 27.3 (5.7) | 28.1 (5.0) | 28.5 (4.8) |
Leisure time physical activity | ||||
High intensity activities | 2 (1) | 0 (0) | 3 (2) | 0 (0) |
Moderate intensity activities | 33 (23) | 22 (22) | 34 (28) | 13 (27) |
Low intensity activities | 85 (60) | 67 (66) | 65 (53) | 26 (53) |
Sedentary | 22 (15) | 13 (13) | 21 (17) | 10 (20) |
Previous knee/hip injury | 85 (60) | 38 (37) | 79 (64) | 25 (51) |
Previous knee/hip surgery | 51 (36) | 12 (12) | 46 (37) | 9 (18) |
Family history of osteoarthritis | ||||
No | 29 (20) | 18 (18) | 30 (24) | 12 (24) |
I don’t know | 23 (16) | 20 (20) | 31 (25) | 11 (22) |
Yes | 90 (63) | 64 (63) | 62 (50) | 26 (53) |
Knee alignment | ||||
Varus | 9 (6) | 4 (4) | 14 (11) | 5 (10) |
Neutral | 110 (79) | 84 (83) | 102 (83) | 43 (88) |
Valgus | 21 (15) | 13 (13) | 7 (6) | 1 (2) |
Foot rotation | ||||
Feet rotated out | 44 (31) | 30 (30) | 59 (48) | 20 (41) |
Straight | 80 (57) | 62 (61) | 62 (50) | 27 (55) |
Feet rotated in | 16 (11) | 9 (9) | 2 (2) | 2 (4) |
Occupational physical exposures | ||||
Bending for 2 h or more | 33 (24) | 29 (29) | 28 (23) | 14 (29) |
Walking for 2 h or more over level ground | 67 (48) | 46 (46) | 71 (58) | 29 (59) |
Kneeling for 30 min or more | 21 (15) | 10 (10) | 41 (33) | 16 (33) |
Squatting for 30 min or more | 18 (13) | 6 (6) | 21 (17) | 9 (18) |
Climbing a total of 5 or more flights of stairs | 14 (10) | 4 (4) | 20 (16) | 9 (18) |
Lifting or moving objects of 10 kg or heavier | 36 (26) | 21 (21) | 57 (46) | 32 (65) |
Driving a car for 4 h or more | 7 (5) | 5 (5) | 21 (17) | 9 (18) |
None of the above | 51 (36) | 41 (41) | 25 (20) | 8 (16) |