Table 3.
Between-Class Differences in Baseline Demographic and Health Characteristics Using Univariate ANOVA or Chi-Squared Testsa
| Characteristic | Full Sample (n = 250) | Class 1, SNS (n = 76) | Class 2, WNS (n = 103) | Class 3, WS (n = 71) | P |
|---|---|---|---|---|---|
| Age, y, mean (SD) | 69.7 (6.8) | 67.4 (6.1) | 71.4 (6.8) | 69.7 (7.0) | <001 |
| Sex, women | 128 (51.2) | 14 (18.4) | 62 (60.2) | 52 (73.2) | <.001 |
| Race, White | 213 (85.2) | 70 (92.1) | 91 (88.3) | 52 (73.2) | .01 |
| Employment status, retired | 182 (72.8) | 47 (61.8) | 81 (78.6) | 54 (76.1) | .03 |
| Education, college graduate | 145 (58.0) | 51 (67.1) | 64 (62.1) | 30 (42.3) | .01 |
| MMSE score ≥24 | 247 (98.8) | 76 (100) | 101 (98.1) | 70 (98.6) | .49 |
| BMI, kg/m2, mean (SD) | 29.4 (5.7) | 27.2 (4.5) | 29.9 (5.4) | 31.3 (6.5) | <.001 |
| GDS-15 score, 0–15, mean (SD) | 2.2 (2.7) | 1.7 (2.4) | 1.7 (2.2) | 3.4 (3.4) | <.001 |
| Heart disease | 31 (12.4) | 10 (13.2) | 9 (8.7) | 12 (16.9) | .25 |
| Stroke | 10 (4.0) | 1 (1.3) | 7 (6.8) | 2 (2.8) | .15 |
| Diabetes | 41 (16.4) | 11 (14.5) | 14 (13.6) | 16 (22.5) | .25 |
| Osteoarthritis | 131 (52.4) | 35 (46.1) | 53 (41.4) | 43 (60.6) | .21 |
| Visual impairment | 95 (38.0) | 30 (39.5) | 36 (35.0) | 29 (40.8) | .70 |
| Hearing impairment | 79 (31.6) | 27 (35.5) | 31 (30.1) | 21 (29.6) | .68 |
| CIRS score, 0–52, mean (SD) | 9.4 (3.8) | 8.1 (3.4) | 9.5 (3.5) | 10.7 (4.1) | <.001 |
| Opioid use | 18 (7.2) | 3 (3.9) | 7 (6.8) | 8 (11.3) | .21 |
| Antidepressant use | 50 (20.0) | 11 (14.4) | 22 (21.4) | 17 (23.9) | .31 |
| Anxiolytic use | 20 (8.0) | 3 (3.9) | 10 (9.7) | 7 (9.9) | .29 |
| Anticonvulsant use | 25 (10.0) | 4 (5.3) | 12 (11.7) | 9 (12.7) | .24 |
| LBP duration, y, mean (SD) | 5.7 (7.7) | 5.8 (7.6) | 5.3 (7.2) | 6.1 (8.7) | .80 |
| FABQ-PA score, 0–24, mean (SD) | 13.5 (6.2) | 13.0 (6.0) | 13.0 (6.2) | 14.9 (6.2) | .11 |
| Composite LBP level, 0–10, mean (SD) | 3.1 (1.5) | 2.9 (1.4) | 2.7 (1.4) | 3.8 (1.5) | <.001 |
| Quebec LBP Disability Questionnaire score, 0–100, mean (SD) | 28.3 (16.6) | 21.6 (12.6) | 26.0 (16.4) | 38.8 (15.8) | <.001 |
| Self-selected gait speed, m/s, mean (SD) | 1.01 (0.23) | 1.14 (0.19) | 0.98 (0.22) | 0.92 (0.23) | <.001 |
| 6-MWD, m, mean (SD) | 488 (133) | 589 (78) | 453 (133) | 429 (119) | <.001 |
a Data are reported as number (percentage) of participants unless otherwise indicated. 6-MWD = 6-min walk test distance; ANOVA = analysis of variance; BMI = body mass index; CIRS = Cumulative Illness Rating Scale; FABQ-PA = Fear Avoidance Beliefs Questionnaire for physical activity; GDS-15 = 15-item Geriatric Depression Scale; LBP = low back pain; MMSE = Mini-Mental State Examination; SNS = strong, no symptoms; WNS = weak, no symptoms; WS = weak, symptoms.