Table 2.
Changes in primary and secondary outcomes for each study period
| Characteristic | Study period 1 | Study period 2 | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Active stimulation | N | Sham stimulation | N | p value | Active stimulation | N | Sham stimulation | N | p value | |
| GCSI | −0.26 ± 0.64 | 63 | −0.17 ± 0.62 | 65 | 0.44 | −0.47 ± 0.78 | 56 | −0.33 ± 0.75 | 52 | 0.34 |
| Nausea/vomiting score | 0.00 (−0.33 to 0.33) | 63 | 0.00 (−0.33 to 0.34) | 65 | 0.84 | −0.33 (−0.67 to 0.00) | 56 | −0.33 (−0.67 to 0.00) | 52 | 0.75 |
| Bloating score | −0.5 (−1.00 to 0.00) | 63 | 0.00 (−1.00 to 0.00) | 65 | 0.62 | −0.5 (−1.50 to 0.00) | 56 | 0.00 (−1.00 to 0.00) | 52 | 0.09 |
| Fullness score | −0.25 (−0.75 to 0.00) | 63 | 0.00 (−0.75 to 0.25) | 65 | 0.21 | −0.25 (−1.00 to 0.00) | 56 | −0.25 (−0.75 to 0.38) | 52 | 0.29 |
| GSRS | −0.35 (0.62) | 62 | −0.32 (0.59) | 64 | 0.77 | −0.46 (0.90) | 58 | −0.35 (0.79) | 53 | 0.50 |
| Reflux score | 0.00 (−0.50 to 0.00) | 62 | 0.00 (−0.75 to 0.25) | 64 | 0.58 | 0.00 (−1.00 to 0.00) | 58 | 0.00 (−0.50 to 0.00) | 53 | 0.89 |
| Abdominal pain score | 0.00 (−0.67 to 0.00) | 62 | −0.33 (−1.00 to 0.33) | 64 | 0.53 | −0.33 (−1.00 to 0.00) | 58 | −0.33 (−0.67 to 0.33) | 53 | 0.54 |
| Indigestion score | −0.38 (−1.00 to 0.00) | 62 | −0.38 (−1.00 to 0.00) | 64 | 0.78 | −0.25 (−1.00 to 0.00) | 58 | −0.50 (−1.00 to 0.00) | 53 | 0.93 |
| Diarrhoea score | −0.34 (−1.33 to 0.00) | 62 | −0.33 (−0.84 to 0.33) | 64 | 0.14 | 0.00 (−0.67 to 0.34) | 58 | 0.00 (−1.00 to 0.67) | 53 | 0.83 |
| Constipation score | −0.33 (−1.00 to 0.00) | 62 | −0.34 (−1.00 to 0.00) | 64 | 0.96 | −0.33 (−1.00 to 0.00) | 58 | 0.00 (−1.00 to 0.34) | 53 | 0.52 |
| Combined weighted symptom score | −0.64 ± 1.16 | 62 | −0.51 ± 1.11 | 64 | 0.51 | −0.99 ± 1.61 | 56 | −0.72 ± 1.49 | 52 | 0.37 |
| Changes in CVT | ||||||||||
| Acute effect | 0.25 (−0.09 to 0.72) | 54 | 0.35 (−0.15 to 1.10) | 56 | 0.42 | 0.03 (−0.53 to 0.49) | 52 | 0.04 (−0.46 to 0.59) | 47 | 0.93 |
| Long-term effect | 0.06 (−0.66 to 0.57) | 48 | 0.06 (−0.93 to 0.58) | 51 | 0.83 | −0.17 (−1.15 to 0.56) | 47 | 0.24 (−0.72 to 0.86) | 41 | 0.14 |
| Changes in the CAN score | ||||||||||
| Lying-to-standing test | 0.00 (−0.02 to 0.04) | 54 | 0.00 (−0.04 to 0.02) | 56 | 0.07 | 0.00 (−0.04 to 0.03) | 54 | 0.00 (−0.05 to 0.02) | 51 | 0.42 |
| Expiration/inspiration test | −0.01 (−0.02 to 0.03) | 57 | −0.02 (−0.06 to 0.02) | 56 | 0.02 | 0.00 (−0.03 to 0.02) | 53 | −0.01 (−0.03 to 0.03) | 51 | 0.99 |
| Valsalva manoeuvre test | 0.01 (−0.10 to 0.16) | 35 | 0.01 (−0.07 to 0.10) | 45 | 0.97 | −0.03 (−0.10 to 0.06) | 37 | 0.01 (−0.05 to 0.08) | 39 | 0.32 |
| Changes in transit times | ||||||||||
| Gastric emptying time, min | 23 (−36 to 116) | 46 | −19 (−90 to 93) | 49 | 0.04 | |||||
| Small-bowel transit time, min | −7.0 (−65 to 47) | 46 | 4.5 (−38 to 45) | 50 | 0.57 | |||||
| Colonic transit time, min | 69 (−1416 to 967) | 46 | 60 (−451 to 744) | 50 | 0.65 | |||||
| Whole-gut transit time, min | 82 (−1419 to 1314) | 46 | 79 (−646 to 922) | 49 | 0.87 | |||||
Data are means ± SD or medians (IQR)
Data are baseline-corrected values for study periods 1 and 2. Thus a negative value represents a reduction in the outcome variable across the stimulation period and a positive value represents an increase