Table 5 Meta-analysis of antidepressant outcomes in all studies with either coil (k = 19 with 20 independent groups)
Random-effects analyses | Primary outcome (depression severity); Hedges’ g (95% CI) | Secondary outcome (response rates); responders/total n (95% CI) | Secondary outcome (remission rates); remitters/total n (95% CI) |
|---|---|---|---|
Pooled weighted effect | |||
 Mean (95% CI); k; n | 1.20 (.96–1.44); k = 20; n = 351 | 29% (20–39%); k = 15; n = 271 (66/271) | 15% (10–22%); k = 12; n = 220 (28/220) |
 Heterogeneity statistics | Q (df 19) = 49.12; p < .001*; I2 = 61% | Q (df 14) = 27.26; p = .018*; I2 = 49% | Q (df 11) = 12.19; p = .350; I2 = 10% |
Publication bias analysis | |||
 Fail-Safe N Rosenthal/Orwin | NRosenthal = 1372; NOrwin = 182 | NRosenthal = 124; NOrwin = 25 | NRosenthal = 187; NOrwin = 8 |
 Funnel plot symmetric? | No: k = 4 missing with small effect sizes | No: k = 2 missing with large response rates | No: k = 6 missing with large remission rates |
 Mean effect (95% CI) adjusted for missing studies | 1.05 (.78–1.32) | 31% (22–42%) | 23% (14–34%) |
Subgroup analysis | |||
Study design | |||
 RCT | 1.17 (.86–1.48); k = 9; n = 173 | 26% (13–47%); k = 6; n = 139 (29/139) | 8% (4–14%); k = 4; n = 118 (9/118) |
 Open-label | 1.24 (.87–1.61); k = 11; n = 178 | 32% (23–42%); k = 9; n = 132 (37/132) | 21% (14–31%); k = 8; n = 102 (19/102) |
 RCT vs. open-label | Q (df 1) = .14, p = .712 | Q (df 1) = 3.03, p = .082 | Q (df 1) = 7.31, p = .007* |
Therapy | |||
 Add-on | 1.20 (.89–1.50); k = 16; n = 231 | 31% (22–43%); k = 11; n = 145 (41/145) | 20% (13–31%); k = 8; n = 94 (16/94) |
 Monotherapy | 1.21 (.98–1.44); k = 4; n = 120 | 23% (10–45%); k = 4; n = 126 (25/126) | 11% (6–19%); k = 4; n = 126 (12/126) |
 Add-on vs. monotherapy | Q (df 1) = 1.15, p = .283 | Q (df 1) = 3.09, p = .079 | Q (df 1) = 3.63, p = .057 |
Meta-regression predictors | |||
 Mean age | b = −.05; p = .019*; R2 = 45%; k = 18 | b = −.11; p = .123; R2 = 2%; k = 15 | b = .06; p = .337; R2 = 23%; k = 12 |
 % female | b < .01; p = .642; R2 = 0%; k = 19 | b < .01; p = .491; R2 = 0%; k = 15 | b < −.01; p = .696; R2 = 0%; k = 12 |
 Mean illness duration | b < −.01; p = .681; R2 = 0%; k = 12 | b = .05; p = .629; R2 = 0%; k = 7 | b = −.04; p = .620; R2 = 0%; k = 7 |
 Mean onset age | b < .01; p = .913; R2 = 0%; k = 12 | b = −.06; p = .327; R2 = 0%; k = 7 | b = .01; p = .811; R2 = 0%; k = 7 |
 Stimuli/session | b < .01; p = .415; R2 = 0%; k = 17 | b < .01; p = .964; R2 = 0%; k = 13 | b < −.01; p = .313; R2 = 25%; k = 11 |
 Trains/session | b < .01; p = .804; R2 = 0%; k = 17 | b = −.03; p = .132; R2 = 32%; k = 13 | b < −.01; p = .858; R2 = 0%; k = 10 |
 Intensity (%MT) | b = .02; p = .007*; R2 = 37%; k = 19 | b < −.01; p = .897; R2 = 0%; k = 15 | b = −.02; p = .087; R2 = 100%; k = 12 |
 Inter-train interval (s) | b = −.01; p = .102; R2 = 0%; k = 17 | b = −.02; p = .234; R2 = 0%; k = 12 | b < .01; p = .996; R2 = 0%; k = 10 |