Table 1.
Demographic and clinical characteristics of controls and low back pain participants in the (A) discovery and (B) validation cohorts*.
| Parameters | Groups | |||||
|---|---|---|---|---|---|---|
| Control women | LBP women | P | Control men | LBP men | P | |
| (A) Discovery cohort | ||||||
| Number | 8 | 8 | — | 8 | 8 | — |
| Age | 43.8 ± 4.6 | 41.3 ± 3.8 | n.s. | 43.8 ± 4.0 | 42.6 ± 3.6 | n.s. |
| Height | 162.1 ± 2.0 | 162.9 ± 2.4 | n.s. | 178.1 ± 1.7 | 176.8 ± 2.4 | n.s. |
| Weight | 64.1 ± 3.5 | 71.8 ± 5.1 | n.s. | 79.9 ± 4.3 | 81.8 ± 2.4 | n.s. |
| BMI | 24.4 ± 1.4 | 26.9 ± 1.5 | n.s. | 25.2 ± 1.3 | 26.2 ± 0.5 | n.s. |
| Pain intensity (0-10) | 0 ± 0 | 5.6 ± 0.6 | P < 0.001 | 0.3 (0.3) | 5.4 (0.8) | P < 0.001 |
| Pain duration (%) | ||||||
| 1–5 y | — | 50 | — | — | 62.5 | — |
| More than 5 y | — | 50 | — | — | 37.5 | — |
| Living condition (%) | ||||||
| Alone | 12.5 | 12.5 | n.s. | 62.5 | 62.5 | n.s. |
| Not alone | 87.5 | 87.5 | n.s. | 37.5 | 37.5 | n.s. |
| Race (%) | ||||||
| White | 87.5 | 62.5 | n.s. | 100 | 62.5 | n.s. |
| Asian or Pacific Islander | 12.5 | 0 | n.s. | 0 | 12.5 | n.s. |
| Black | 0 | 37.5 | n.s. | 0 | 12.5 | n.s. |
| Others | 0 | 0 | n.s. | 0 | 12.5 | n.s. |
| Education (%) | ||||||
| Less than high school | 0 | 0 | n.s. | 0 | 0 | n.s. |
| High school | 0 | 0 | n.s. | 0 | 0 | n.s. |
| College, certificate | 37.5 | 62.5 | n.s. | 25 | 25 | n.s. |
| Bachelor's degree | 25 | 12.5 | n.s. | 37.5 | 12.5 | n.s. |
| Master's degree, certificate above bachelor | 12.5 | 25 | n.s. | 12.5 | 50 | n.s. |
| Higher than master's degree | 25 | 0 | n.s. | 25 | 12.5 | n.s. |
| ODI (/50) | 0.1 ± 0.1 | 9.1 ± 1.7 | P < 0.001 | 0.4 ± 0.4 | 6.5 ± 1.5 | P < 0.001 |
| Anxiety score (/21) | 3.1 ± 0.6 | 4.9 ± 1.6 | n.s. | 2.3 ± 1.1 | 5.5 ± 0.8 | P < 0.05 |
| Depression score (/21) | 0.8 ± 0.4 | 3.8 ± 1.1 | P < 0.05 | 0.8 ± 0.5 | 3.5 ± 0.6 | P < 0.01 |
| DN4 (/7) | 0.0 ± 0.0 | 2.8 ± 0.8 | P < 0.01 | 0.0 ± 0.0 | 2.3 ± 0.8 | P < 0.01 |
| EQ-5D-5L (/25) | 5.0 ± 0.0 | 8.9 ± 0.7 | P < 0.001 | 5.1 ± 0.1 | 8.1 ± 0.5 | P < 0.001 |
| SCL-90-R (/48) | 1.3 ± 0.3 | 7.3 ± 1.6 | P < 0.01 | 1.1 ± 0.7 | 7.0 ± 1.7 | P < 0.01 |
| PCS (/52) | 5.4 ± 2.5 | 15.3 ± 3.7 | P < 0.05 | 6.1 ± 3.1 | 12.9 ± 4.0 | n.s. |
| Parameters | Groups | |||||
|---|---|---|---|---|---|---|
| Control women | LBP women | P | Control men | LBP men | P | |
| (B) Validation cohort | ||||||
| Number | 13 | 19 | — | 13 | 18 | — |
| Age | 38.5 ± 3.5 | 46.1 ± 2.7 | n.s. | 43.1 ± 3.2 | 48.4 ± 2.6 | n.s. |
| Height | 165.5 ± 1.7 | 163.2 ± 1.7 | n.s. | 175.5 ± 2.2 | 175.8 ± 1.9 | n.s. |
| Weight | 64.6 ± 2.9 | 64.1 ± 2.6 | n.s. | 77.5 ± 3.4 | 84.2 ± 2.5 | n.s. |
| BMI | 23.6 ± 1.0 | 23.9 ± 0.9 | n.s. | 25.1 ± 0.9 | 27.3 ± 0.7 | n.s. |
| Pain intensity (0-10) | 0.1 ± 0.1 | 6.9 ± 0.5 | P < 0001 | 0 (0) | 6.6 (0.4) | P < 0.0001 |
| Pain duration (%) | ||||||
| 1–5 y | — | 47.4 | — | — | 44.4 | — |
| More than 5 y | — | 52.6 | — | — | 55.6 | — |
| Living condition (%) | ||||||
| Alone | 23.1 | 15.8 | n.s. | 53.8 | 27.8 | n.s. |
| Not alone | 76.9 | 84.2 | n.s. | 46.2 | 72.2 | n.s. |
| Race (%) | ||||||
| White | 46.1 | 68.4 | n.s. | 69.2 | 44.45 | n.s. |
| Asian or Pacific Islander | 15.4 | 5.3 | n.s. | 15.4 | 0 | n.s. |
| Black | 15.4 | 15.8 | n.s. | 0 | 11.1 | n.s. |
| Others | 23.1 | 10.5 | n.s. | 15.4 | 44.45 | n.s. |
| Education (%) | ||||||
| Less than high school | 0 | 0 | n.s. | 0 | 0 | n.s. |
| High school | 0 | 10.5 | n.s. | 7.7 | 22.2 | n.s. |
| College, certificate | 15.4 | 42.1 | n.s. | 30.8 | 27.8 | n.s. |
| Bachelor's degree | 15.4 | 15.8 | n.s. | 38.4 | 22.2 | n.s. |
| Master's degree certificate above bachelor | 53.8 | 21.1 | n.s. | 7.7 | 27.8 | n.s. |
| Higher than master's degree | 15.4 | 10.5 | n.s. | 15.4 | 0 | n.s. |
| ODI (/50) | 0.5 ± 0.3 | 14.2 ± 1.2 | P < 0.001 | 0.1 ± 0.1 | 11.1 ± 1.3 | P < 0.0001 |
| Anxiety score (/21) | 2.5 ± 0.7 | 8.9 ± 1.0 | P < 0.001 | 3.1 ± 0.7 | 7.3 ± 0.9 | P < 0.01 |
| Depression score (/21) | 1.6 ± 0.8 | 6.6 ± 0.9 | P < 0.0001 | 1.5 ± 0.6 | 5.9 ± 1.0 | P < 0.0001 |
| DN4 (/7) | 0.0 ± 0.0 | 3.2 ± 0.5 | P < 0.0001 | 0.0 ± 0.0 | 2.3 ± 0.4 | P < 0.0001 |
| EQ-5D-5L (/25) | 5.3 ± 0.2 | 10.6 ± 0.8 | P < 0.0001 | 5.2 ± 0.1 | 9.6 ± 0.5 | P < 0.0001 |
| SCL-90-R (/48) | 1.5 ± 0.4 | 13.5 ± 1.9 | P < 0.0001 | 0.3 ± 0.2 | 9.9 ± 1.6 | P < 0.0001 |
| PCS (/52) | 7.8 ± 2.2 | 25.8 ± 3.2 | P < 0.01 | 3.1 ± 1.4 | 19.2 ± 2.8 | P < 0.0001 |
Categorical variables were analyzed using the Fisher exact test. Continuous variables are expressed as mean ± SEM, and an unpaired t test or the Mann–Whitney U test was used to compare control and LBP participants.
BMI, body mass index; DN4, Douleur Neuropathique 4; EQ, EuroQol; LBP, low back pain; ODI, Oswestry Disability Index; PCS, Pain Catastrophizing Scale; SCL, symptoms checklist.