Table 3.
Summary of findings with estimated certainty of evidence.
| Outcome | Number and type of studies (participants), risk of bias | Absolute effect estimates | Certainty of evidence – GRADE a |
|---|---|---|---|
| PTSD symptoms | 2 RCTs (n = 88) with Low Risk of Bias |
CAPS Standardised mean difference at end of treatment in favour of NFB – 0.88 (95% CI −1.42, −0.35), p = .001 |
⊕ ⊕ ⊕ ◯ b |
| 5 RCTs (n = 127) with High Risk of Bias |
IES-R/PCL-5/MMPI-PTSD/Non-validated PTSD Questionnaire Standardised mean difference at end of treatment in favour of NFB –2.39 (95% CI −3.87. −0.90), p = .00001 |
⊕ ◯ ◯ ◯ c | |
| Symptoms of Depression | 2 RCTs (n = 49) and 1 NRSI (n = 26) with High Risk of Bias |
Beck Depression Inventory/HSCL-D Standardised mean difference at end of treatment in favour of NFB −1.37 (95% CI −2.21 to −0.53), p = .001 |
⊕ ◯ ◯ ◯ d |
| Symptoms of Anxiety | 1 RCT (n = 19) and 2 NRSI (n = 49) with High Risk of Bias |
Beck Anxiety Inventory /HSCL-A Standardised mean difference at end of treatment in favour of NFB −1.00 (95% CI −1.51 to −0.49), p = .0001 |
⊕ ◯ ◯ ◯ e |
| Medication use | 1 RCT (28) and 1 NRSI (n = 13) | Number of patients with decreased medication use NFB vs CL: Decrease: 22/22 vs. 1/18 Between-group difference: Chi2 = 36.14, p < .001 |
⊕ ◯ ◯ ◯ f |
| ⊕⊕⊕⊕ – High certainty (we are very confident that the true effect lies close to that of the estimate of the effect) | |||
| ⊕⊕⊕ ◯ Moderate certainty (we are moderately confident in the effect estimate: the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different) | |||
| ⊕⊕ ◯ ◯ Low certainty (our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect) | |||
| ⊕ ◯ ◯ ◯ Very low certainty (we have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect) | |||
a, certainty of evidence; b, downgraded one step for imprecision (due to a small number of participants and only 2 events); c,d,e,f downgraded three steps for serious risk of bias and study limitations (missing outcome data, unclear randomisation, deviation from intended intervention and bias in measurement of outcomes), high heterogeneity, indirectness, and serious imprecision.