TABLE 2.
Certainty Assessment |
Certainty |
||||
No. of Studies |
Risk of Bias |
Inconsistency |
Indirectness |
Imprecision |
|
Negative symptom domain (follow up: range 8 to 24 wk; assessed with PANSS negative score) | |||||
3 | Seriousa | Seriousb | Not serious | Not serious | ++○○ Low |
Cognition symptom domain (follow up: range 12 to 24 wk; assessed with various scales) | |||||
2c | Not serious | Seriousd | Not serious | Seriouse | ++○○ Low |
Positive symptom domain (follow up: range 8 to 24 wk; assessed with PANSS positive score) | |||||
3 | Seriousf | Not serious | Not serious | Not serious | +++○ Moderate |
Treatment attrition for any reason (follow up: range 8 to 24 wk; assessed with all-cause discontinuation) | |||||
3 | Not serious | Seriousg | Not serious | Not serious | +++○ Moderate |
PANSS = Positive and Negative Syndrome Scale.
Selective reporting and incomplete outcomes data in study by Sepehrmanesh et al23; did not include prespecified between-group differences in mean PANSS score changes at trial end point. Instead, included findings with F statistic from ANOVA. No SD reported with mean PANSS score, yielding inability to complete t test analysis through independent investigator using summarized data.
Although consistency of findings were reported among all 3 trials,21-23 the statistics provided by Sepehrmanesh et al23 did not show a between-group difference as stated in the text. So evidence is lacking to state that all 3 studies were consistent in finding.
Berk et al21 found no differences in subgroup of patients analyzed, whereas Sepehrmanesh et al23 found benefits with N-acetylcysteine across all cognitive function assessments.
Cannot assess magnitude of effect given published data from Sepehrmanesh et al23 and unable to assess sample size in each group within Berk et al21 study, which was likely not powered to detect a difference.
Selective reporting and incomplete outcomes data in study by Sepehrmanesh et al23; did not include prespecified between-group differences in mean PANSS score changes at trial end point. Instead, included findings with F statistic from ANOVA. No SD reported with mean PANSS score, yielding inability to complete t test analysis through independent investigator using summarized data.
Large variability in reported drug reactions and discontinuations between studies.