Table 1.
Participant characteristics and prevalence of MRI findings in LBP and no-LBP groups including test for group difference. The MRI findings are based on the worst score at any lumbar level (L1-L5)
| 41 Years | ||||
|---|---|---|---|---|
| Characteristics | Total n = 412 |
LBP Year n = 284 (68.93%) |
No LBP Year n = 128 (31.07%) |
P-Value |
| Sex | ||||
| Men n (%) | 199 (48.30) | 134 (47.18) | 65 (50.78) | 0.499 |
| Women n (%) | 213 (51.70) | 150 (52.82) | 63 (49.22) | |
| BMI Mean (SD) | 25.05 (4.25) | 25.24 (4.28) | 24.63 (4.19) | 0.176 |
| MRI Findings | ||||
| Signal Intensity (worst lumbar level) | ||||
| Grade 0 n (%) | 4 (0.97) | 3 (1.06) | 1 (0.78) | |
| Grade 1 n (%) | 51 (12.38) | 28 (9.86) | 23 (17.97) | |
| Grade 2 n (%) | 171 (41.50) | 105 (36.97) | 66 (51.56) | |
| Grade 3 n (%) | 186 (45.15) | 148 (52.11) | 38 (29.69) | 0.000*a |
| Disc Height (worst lumbar level) | ||||
| Grade 0 n (%) | 90 (21.84) | 56 (19.72) | 34 (26.56) | |
| Grade 1 n (%) | 103 (25.00) | 57 (20.07) | 46 (35.94) | |
| Grade 2 n (%) | 207 (50.24) | 161 (56.69) | 46 (35.94) | |
| Grade 3 n (%) | 12 (2.91) | 10 (3.52) | 2 (1.56) | 0.000*a |
| 45 Years | ||||
| Characteristics |
Total n = 348 |
LBP Year n = 238 (68.39%) |
No LBP Year n = 110 (31.61%) |
P-Value |
| Sex | ||||
| Men n (%) | 161 (46.26) | 109 (45.80) | 52 (47.27) | 0.798 |
| Women n (%) | 187 (53.74) | 129 (54.20) | 58 (52.73) | |
| BMI Mean (SD) | 25.16 (4.05) | 25.43 (4.23) | 24.57 (3.60) | 0.051 |
| MRI Findings | ||||
| Signal Intensity (worst lumbar level) | ||||
| Grade 0 n (%) | 0 | 0 | 0 | |
| Grade 1 n (%) | 52 (15.12) | 28 (11.81) | 24 (22.43) | |
| Grade 2 n (%) | 121 (35.17) | 89 (37.55) | 32 (29.91) | |
| Grade 3 n (%) | 171 (49.71) | 120 (50.63) | 51 (47.66) | 0.033*b |
| Disc Height (worst lumbar level) | ||||
| Grade 0 n (%) | 107 (31.10) | 73 (30.80) | 34 (31.78) | |
| Grade 1 n (%) | 69 (20.06) | 48 (20.25) | 21 (19.63) | |
| Grade 2 n (%) | 154 (44.77) | 109 (45.99) | 45 (42.06) | |
| Grade 3 n (%) | 14 (4.07) | 7 (2.95) | 7 (6.54) | 0.458a |
| 49 Years | ||||
| Characteristics |
Total n = 293 |
LBP Year n = 204 (69.62%) |
No LBP Year n = 89 (30.38%) |
P-Value |
| Sex | ||||
| Men n (%) | 136 (46.42) | 85 (41.67) | 51 (57.30) | 0.014* |
| Women n (%) | 157 (53.58) | 119 (58.33) | 38 (42.70) | |
| BMI Mean (SD) | 27.28 (17.84) | 28.19 (21.21) | 25.21 (3.44) | 0.054 |
| MRI Findings | ||||
| Signal Intensity (worst lumbar level) | ||||
| Grade 0 n (%) | 0 | 0 | 0 | |
| Grade 1 n (%) | 31 (10.88) | 15 (7.54) | 16 (18.60) | |
| Grade 2 n (%) | 154 (54.04) | 109 (54.77) | 45 (52.33) | |
| Grade 3 n (%) | 100 (35.09) | 75 (37.69) | 25 (29.07) | 0.017*b |
| Disc Height (worst lumbar level) | ||||
| Grade 0 n (%) | 44 (15.44) | 23 (11.56) | 21 (24.42) | |
| Grade 1 n (%) | 52 (18.25) | 36 (18.09) | 16 (18.60) | |
| Grade 2 n (%) | 160 (56.14) | 120 (60.30) | 40 (46.51) | |
| Grade 3 n (%) | 29 (10.18) | 20 (10.05) | 9 (10.47) | 0.037*b |
* = Statistically significant difference between LBP and no-LBP groups (P-value < 0.05)
a = P-value was obtained using Fischer’s exact test
b = P-value was obtained using Pearson’s chi2 test