Table I. Baseline characteristics of participants with and without comorbidities.
|
All
(n = 24513) |
No comorbidities
(n = 12,128) |
Comorbidities
(n = 12,385) |
|
|---|---|---|---|
| Most affected joint, n (%) | |||
| Knee | 18,271 (75) | 8,923 (74) | 9,348 (75) |
| Hip | 6,242 (25) | 3,205 (26) | 3,037 (25) |
| Age, years (SD) | 64.7 (9.7) | 62.9 (10.1) | 66.5 (9.0) |
| Female, n (%) | 17,799 (73) | 9,052 (75) | 8,747 (71) |
| BMI, kg/m2 (SD)a | 28.2 (5.2) | 27.3 (4.9) | 29.1 (5.4) |
| Educational level, n (%)b | |||
| Primary school | 4,243 (17) | 1,738 (14) | 2,505 (20) |
| Secondary school | 2,736 (11) | 1,329 (11) | 1,407 (11) |
| Short-term educationc | 4,819 (20) | 2,373 (20) | 2,446 (20) |
| Middle-term educationd | 9,870 (40) | 5,145 (42) | 4,725 (38) |
| Long-term educatione | 2,834 (12) | 1,541 (13) | 1,293 (10) |
| Born outside Denmark, n (%)f | 917 (4) | 466 (4) | 451 (4) |
| Living alone, n (%)g | 6,216 (25) | 2,751 (23) | 3,465 (28) |
| Physical activity level, n (%)h | |||
| Inactive | 524 (2) | 200 (2) | 324 (3) |
| Low (e.g. walking and limited housework) | 7,114 (29) | 3,046 (25) | 4,068 (33) |
| Moderate (e.g. swimming and unlimited housework) | 8,104 (33) | 4,007 (33) | 4,097 (33) |
| High (e.g. prolonged biking and fitness) | 7,125 (29) | 3,870 (32) | 3,255 (26) |
| Very high (e.g. running, tennis and skiing) | 1,627 (7) | 995 (8) | 632 (5) |
| Pain in other knee or hip joints, n (%) | |||
| No | 10,535 (43) | 5,387 (44) | 5,148 (42) |
| Bilateral joint (from most affected joint) | 8,696 (35) | 4,294 (35) | 4,402 (36) |
| Hip or kneei | 4,200 (17) | 1,966 (16) | 2,234 (18) |
| Bilateral joint and hip or kneei | 1,082 (4) | 481 (4) | 601 (5) |
| Number of bodily pain areas, n (%) | |||
| 0 | 679 (3) | 356 (3) | 323 (3) |
| 1-2 | 10,966 (45) | 5,656 (47) | 5,310 (43) |
| 3-4 | 6,732 (27) | 3,290 (27) | 3,442 (28) |
| 5-6 | 2,838 (12) | 1,370 (11) | 1,468 (12) |
| 7 or more | 3,298 (13) | 1,456 (12) | 1,842 (15) |
| Use of analgesics within recent 3 monthsj | 15,415 (63) | 7,267 (60) | 8,148 (66) |
| Quality of life (EQ-5D-5L, -0.624 to 1.000), mean (SD)k | 0.714 (0.112) | 0.724 (0.107) | 0.703 (0.115) |
| Pain intensity (VAS, 0-100 mm), mean (SD)l | 47.4 (21.9) | 45.9 (21.8) | 48.9 (21.9) |
| 40m Fast-Paced Walk Test, m/s (SD)m | 1.50 (0.33) | 1.56 (0.33) | 1.43 (0.32) |
n: Number, SD: Standard Deviation, BMI: Body Mass Index (kg/m2), VAS: Visual Analogue Scale.
a
69 missing observations,
b
11 missing observations,
c
under 3 years after secondary school,
d
3-4 years after secondary school,
e
at least 5 years after secondary school.
f
7 missing observations,
g
7 missing observations,
h
19 missing observations,
i
hip if most affected joint is knee and vice versa,
j
at least one of the following: Acetaminophen, oral or topical Non-Steroidal Anti-inflammatory Drug (NSAID), Morphine, Tramadol, or Codeine,
k
21 missing observations,
l
30 missing observations,
m
1,350 missing observations.