Table 2.
Differences between groups. Change scores in periods, sequences, and total (IMT-PBT: N = 11; PBT-IMT: N = 9; total: N = 20)
| Outcome | Sequence | Period 1 | Period 2 | IMT minus PBT | Total IMT minus PBT | p value* |
|---|---|---|---|---|---|---|
| Mean (SD) | Mean (SD) | Mean of differences (SD) | Mean of differences (95% CI) | |||
| Average pain | IMT-PBT | − 0.8 (1.0) | − 0.4 (1.0) | − 0.5 (1.4) | − 0.2 (− 0.9 to 0.6) | 0.6590 |
| NRS: 0–10 | PBT-IMT | − 1.2 (1.5) | − 1.0 (1.4) | 0.2 (1.6) | ||
| Worst pain | IMT-PBT | − 1.4 (1.7) | − 1.4 (2.1) | 0.0 (2.6) | 0.3 (− 1.1 to 1.6) | 0.7125 |
| NRS: 0–10 | PBT-IMT | − 1.8 (3.1) | − 1.2 (1.3) | 0.6 (3.6) | ||
| Least pain | IMT-PBT | − 0.5 (1.1) | − 0.4 (1.2) | − 0.1 (2.0) | − 0.2 (− 1.1 to 0.7) | 0.6295 |
| NRS: 0–10 | PBT-IMT | − 0.7 (1.4) | − 1.0 (0.9) | − 0.3 (1.7) | ||
| Quality of life | IMT-PBT | 0.7 (1.4) | 0.1 (1.3) | 0.6 (2.0) | − 0.1 (− 1.0 to 0.8) | 0.8252 |
| Scale: 1–7 | PBT-IMT | 0.9 (1.4) | − 0.1 (1.2) | − 1.0 (1.7) | ||
| General activity | IMT-PBT | − 1.0 (3.2) | − 1.5 (2.6) | 0.5 (4.5) | 0.0 (− 2.2 to 2.2) | 1.0000 |
| NRS: 0–10 | PBT-IMT | − 1.2 (4.0) | − 1.9 (2.9) | − 0.7 (5.1) | ||
| Mood | IMT-PBT | 0.0 (3.3) | − 0.5 (2.9) | 0.5 (3.9) | 0.3 (− 1.5 to 2.1) | 0.7351 |
| NRS: 0–10 | PBT-IMT | − 2.1 (3.9) | − 2.0 (1.7) | 0.1 (4.1) | ||
| Walking ability | IMT-PBT | − 1.8 (3.9) | 0.4 (2.1) | − 2.2 (4.5) | − 1.0 (− 2.9 to 1.0) | 0.3229 |
| NRS: 0–10 | PBT-IMT | − 2.3 (3.7) | − 1.8 (2.2) | 0.6 (3.5) | ||
| Normal work | IMT-PBT | − 2.7 (3.6) | 0.6 (2.9) | − 3.4 (5.5) | − 1.6 (− 4.0 to 0.8) | 0.1745 |
| NRS: 0–10 | PBT-IMT | − 2.6 (3.1) | − 2.0 (2.1) | 0.6 (3.8) | ||
| Relations | IMT-PBT | 0.7 (2.7) | 0.1 (1.9) | 0.6 (3.6) | − 0.4 (− 1.9 to 1.1) | 0.5790 |
| NRS: 0–10 | PBT-IMT | 0.0 (1.7) | − 1.7 (1.3) | − 1.7 (2.1) | ||
| Sleep | IMT-PBT | − 1.0 (2.3) | 0.7 (3.0) | − 1.7 (3.1) | − 0.8 (− 2.5 to 0.9) | 0.3279 |
| NRS: 0–10 | PBT-IMT | − 1.7 (4.0) | − 1.3 (2.2) | 0.3 (3.9) | ||
| Enjoyment of life | IMT-PBT | − 0.1 (4.0) | 0.0 (2.2) | − 0.1 (5.1) | − 0.1 (− 2.1 to 1.9) | 0.9185 |
| NRS: 0–10 | PBT-IMT | − 1.7 (3.2) | − 1.8 (1.4) | − 0.1 (3.5) |
EORTC QLQ-C30, European Organization for Research and Treatment of Cancer quality-of-life questionnaire core 30; IMT, intensity-modulated high TENS; NRS, numerical rating scale; PBT, placebo TENS; SD, standard deviation; TENS, transcutaneous electrical nerve stimulation
NRS items adapted from the Brief Pain Inventory: 0 = no pain or no interference; 10 = worst imaginable pain or maximum interference; quality of life scale: 1 = very poor, 7 = excellent
Sequence IMT-PBT, N = 11; sequence PBT-IMT, N = 9; total, N = 20; quality of life was measured with the EORTC QLQ-C30 quality of life item; item “Pain relief with TENS” not listed: provides only post treatment values
*p value testing difference between treatments: paired t test of within-subject differences of pre-post change scores from both periods; p values < 0.05: statistically significant difference between treatments (Li et al., 2015); checking carry-over effect: unpaired t test of within-subject sums of the result from both periods: all p values were ≥ 0.05: carry-over effect is negligible (Wellek & Blettner, 2012)