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. 2022 Mar 2;2022(3):CD002795. doi: 10.1002/14651858.CD002795.pub3

Summary of findings 4. Comparison 4: NaSSAs versus placebo for posttraumatic stress disorder (PTSD).

Comparison 4: NaSSAs versus placebo for posttraumatic stress disorder (PTSD)
Population: adults (aged 18‐85)
Settings: single‐centre trial
Intervention: NaSSA
Comparison: placebo
Follow‐up: not specified
Outcomes Illustrative comparative risks* (95% CI) Relative effect
(95% CI) No of participants
(studies) Quality of the evidence
(GRADE) Comments
Assumed risk Corresponding risk
With placebo With NaSSAs
Treatment efficacy ‐ Treatment response, as measured by the Global Impressions scale change item (CGI‐I or similar): no. of responders (acute phase) Study population RR 0.45 
(0.22 to 0.94) 26
(1 study) ⊕⊕⊝⊝
lowa,b There was evidence of a benefit for the number of participants with PTSD who responded to treatment (65%) compared to placebo (22%). This is also indicated by the Risk Ratio of 0.45 which indicates that there is a statistically significantly greater number of people in the NaSSA group compared to the placebo group who improved on the CGI‐I scale
222 per 1000 100 per 1000
(49 to 209)
Moderate
222 per 1000 100 per 1000
(49 to 209)
Treatment tolerability, as measured by Dropouts due to adverse events (acute phase) Study population RR 0.87 
(0.68 to 1.11) 36
(1 study) ⊕⊕⊝⊝
lowa,b The proportion of dropouts due to adverse events was high in participants receiving the NaSSA (18%) relative to placebo (5%), but there was no
evidence of a harm between the numbers of participants that dropped out due to adverse events
53 per 1000 176 per 1000
(20 to 1000)
Moderate
53 per 1000 178 per 1000
(20 to 1000)
*The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: confidence interval; CGI‐I: Clinical Global Impressions Improvement scale; CAPS: Clinically Administered PTSD Scale;RR: risk ratio
GRADE Working Group grades of evidence
High quality: Further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: We are very uncertain about the estimate.

aDowngraded by one level due to serious risk of bias (concerns with randomisation procedures).
bDowngraded by one level due to serious imprecision (wide confidence intervals).