Table 6.
Analysis of heterogeneity of clinical studies, including evaluation of treatment time, outcome measure, and assessment time follow-up for all 3 types of electrical stimulation.*
| Number of studies for DC (n) | Number of studies for CC (n) | Number of studies for PEMF (n) | ||
|---|---|---|---|---|
| A | ||||
| Treatment time | ||||
| ≥3 mo duration | 11 | 1 | 15 | |
| 3- to ≥6-mo duration | 4 | 4 | 9 | |
| 6-mo to ≥ 1-y duration | 5 | 1 | 10 | |
| >1 y duration | 3 | 0 | 2 | |
| Until union duration | 7 | 5 | 14 | |
| Not state duration of treatment | 1 | 0 | 5 | |
| 24 h per day | NA | 2 | 1 | |
| 10-16 h per day | NA | 2 | 25 | |
| 0.5-8 h | NA | 0 | 10 | |
| Not state time per day | NA | 7 | 19 | |
| B | ||||
| Outcome measure | ||||
| Radiographic | 19 | 5 | 22 | |
| Clinical | 1 | 0 | 7 | |
| Radiographic and Clinical | 11 | 5 | 21 | |
| Hoping for 30 s | 0 | 1 | 0 | |
| Bone density | 0 | 0 | 2 | |
| Time to weight bear | 0 | 0 | 1 | |
| Scintimetric analysis | 0 | 0 | 1 | |
| Time to consolidation | 0 | 0 | 1 | |
| C | ||||
| Assessment time follow-up | ||||
| ≥3 mo | 8 | 2 | 7 | |
| 3 to ≥6 mo | 3 | 3 | 5 | |
| 6 mo to ≥1 y | 7 | 2 | 11 | |
| >1 y | 7 | 0 | 6 | |
| Until union | 6 | 4 | 25 | |
| Not state | 00 0 | 0 | 1 |
*DC indicates direct current; CC, capacitive coupling; PEMF, pulsed electromagnetic field.