Table 5.
Secondary outcomes at M1 and M3: ITT population.
| Outcomes Mean (SD) |
Month 1 | Month 3 | ||||||
|---|---|---|---|---|---|---|---|---|
| W-TENS group | WO group | Between-group difference | p-value | W-TENS group | WO group | Between-group difference | p-value | |
| WOMAC: Global score | ||||||||
| Mean (SD) | 38.4 (16.8) | 42.9 (15.5) | –4.8 (2.6) | 0.0635 | 33.9 (19.8) | 42.2 (17.2) | –8.5 (3.3) | 0.0106 |
| 95% CI | [33.8, 42.9] | [38.7, 47.7] | [–9.8, 0.3] | [28.6, 39.3] | [37.5, 46.9] | [14.9, –2.0] | ||
| WOMAC: Pain subscore | ||||||||
| Mean (SD) | 9.0 (3.5) | 9.5 (3.5) | –0.6 (0.6) | 0.3047 | 7.9 (4.4) | 9.2 (3.6) | –1.5 (0.8) | 0.0570 |
| 95% CI | [8.0, 9.9] | [8.5, 10.4] | [–1.8, 0.6] | [6.8, 9.1] | [8.2, 10.2] | [–2.9, 0.0] | ||
| WOMAC: Physical function subscore | ||||||||
| Mean (SD) | 25.7 (12.4) | 29.1 (11.6) | –3.5 (1.8) | 0.0631 | 22.7 (14.0) | 28.9 (12.9) | –6.2 (2.3) | 0.0083 |
| 95% CI | [22.3, 29.0] | [25.9, 32.3] | [–7.2, 0.2] | [18.9, 26.5] | [25.4, 32.4] | [–10.8, –1.6] | ||
| WOMAC: Stiffness subscore | ||||||||
| Mean (SD) | 3.7 (2.0) | 4.3 (1.7) | –0.6 (0.3) | 0.0708 | 3.2 (2.3) | 4.0 (1.9) | –0.8 (0.4) | 0.0296 |
| 95% CI | [3.2, 4.3] | [3.9, 4.8] | [–1.2, 0.0] | [2.6, 3.8] | [3.5, 4.5] | [–1.5, –0.1] | ||
| Pain intensity (PI, NRS) | ||||||||
| Mean (SD) | 4.1 (2.1) | 5.3 (1.9) | –1.3 (0.4) | 0.0010 | 3.8 (2.1) | 4.7 (2.3) | –0.9 (0.4) | 0.0174 |
| 95% CI | [3.5, 4.6] | [4.8, 5.8] | [–2.0, –0.5] | [3.3, 4.4] | [4.1, 5.4] | [–1.7, –0.2] | ||
| Pain intensity differences (PID) | ||||||||
| Mean (SD) | 1.8 (2.1) | 0.5 (1.8) | 1.3 (0.4) | 0.0007 | 2.1 (2.3) | 1.1 (2.1) | 0.9 (0.4) | 0.0247 |
| 95% CI | [1.3, 2.4] | [0.0, 1.0] | [0.6, 2.0] | [1.4, 2.7] | [0.5, 1.7] | [0.2, 1.7] | ||
| Patient-responders (PR) rates | ||||||||
| PI reduction ⩾30%: n (%) | ||||||||
| n (%) | 31 (56.4) | 10 (18.2) | < 0.0001 | 29 (52.7) | 19 (34.5) | 0.0545 | ||
| 95% CI | [43.3, 69.5] | [8.0, 28.4] | [39.5, 65.9] | [22.0, 47.1] | ||||
| PI reduction ⩾50%: n (%) | ||||||||
| n (%) | 19 (34.5) | 5 (9.1) | 0.0012 | 21 (38.2) | 13 (23.6) | 0.0988 | ||
| 95% CI | [22.0, 47.1] | [1.5, 16.7] | [25.3, 51.0] | [12.4, 34.9] | ||||
| OMERAC-OARSI | ||||||||
| n (%) | 24 (43.6) | 13 (23.6) | 0.0264 | 30 (54.5) | 18 (32.7) | 0.0211 | ||
| 95% CI | [41.4, 67.7] | [12.4, 34.9] | [41.4, 67.7] | [20.3, 45.1] | ||||
| MCII Pain (absolute) | ||||||||
| n (%) | 31 (56.4) | 14 (25.5) | 0.0010 | 30 (54.5) | 20 (36.4) | 0.0555 | ||
| 95% CI | [43.3, 69.5] | [13.9, 37.0] | [41.4, 67.7] | [23.7, 49.1] | ||||
| MCII Pain (relative) | ||||||||
| n (%) | 34 (61.8) | 14 (25.5) | 0.0001 | 33 (60.0) | 25 (45.5) | 0.1266 | ||
| 95% CI | [49.0, 74.7] | [13.9, 37.0] | [47.1, 72.9] | [32.8, 58.6] | ||||
| MCII WOMAC Function (absolute) | ||||||||
| n (%) | 18 (32.7) | 13 (24.1) | 0.3167 | 21 (38.2) | 13 (24.1) | 0.1119 | ||
| 95% CI | [20.3, 45.1] | [12.7, 35.5] | [25.3, 51.0] | [12.7, 35.5] | ||||
| MCII WOMAC Function (relative) | ||||||||
| n (%) | 28 (50.9) | 17 (31.5) | 0.0394 | 29 (52.7) | 19 (35.2) | 0.0651 | ||
| 95% CI | [37.7, 64.1] | [19.1, 43.9] | [39.5, 65.9] | [22.4, 47.9] | ||||
| PASS (pain) | ||||||||
| n (%) | 29 (52.7) | 14 (25.5) | 0.0034 | 29 (52.7) | 23 (41.8) | 0.2519 | ||
| 95% CI | [39.5, 65.9] | [13.9, 37.0] | [39.5, 65.9] | [28.8, 54.9] | ||||
| PASS (WOMAC Function) | ||||||||
| n (%) | 31 (56.4) | 22 (40.7) | 0.1028 | 36 (65.5) | 22 (40.7) | 0.0097 | ||
| 95% CI | [43.3, 69.5] | [27.6, 53.8] | [52.9, 78.0] | [27.6, 53.8] | ||||
ANOVA, analysis of variance; CI, confidence interval; MCII, minimum clinically important improvement (⩾15 on a 0–100 scale or ⩾2 on a 0–10 NRS for absolute improvement, and ⩾20% for relative improvement on pain and WOMAC function); NRS, Numerical Rating Scale (0 = non-pain; 10 = Maximal pain as you can imagine); OMERAC-OARSI, criteria: improvement in pain or physical function ⩾50% and an absolute change ⩾20 mm; or improvement of ⩾20% with an absolute change ⩾10 mm in at least two of the following three categories: pain, physical function, and patient’s global assessment; PASS, patient acceptable symptom state (⩽40 on a 0–100 scale or ⩽4 on 0–10 NRS for pain and WOMAC Function); PI, pain intensity; PID, pain intensity difference; SD, standard deviation; WO, weak opioid; WOMAC, Western Ontario and McMaster University Osteoarthritis Index, Global score: 0–96 (24 items, 0–4), Pain subscore: 0–20 (5 items, 0–4), Function subscore: 0–68 (17 items, 0–4) and Stiffness subscore: 0–8 (2 items, 0–4); W-TENS, wearable transcutaneous electrical nerve stimulation.
Study group: one-way ANOVA on outcomes (rank data) at M1 and M3, Least squares means, ITT population. Study group: p-value < 0.0001.
Between-study group differences: one-way ANOVA on outcomes (rank data) at M1 and M3. Means (SD) and corresponding 95% confidence interval (CI).
For quantitative data, values are scores (SD) and 95% CI; for responders analyses, results are given as numbers (%) of responders (YES) and 95% CI. Chi-square test or Fisher exact test at M1 and M3.