Thirteen RCTs (n=564) were included in the meta-analysis.
No significant effect of cholinesterase inhibitors was found for the outcomes of executive function (six studies, n=199), language (four studies, n=63), total PANSS (six studies, n=119) and negative PANSS (eight studies, n=377). There was a trend towards improvement in extrapyramidal symptoms with cholinesterase inhibitors (effect size -0.57, 95% CI -1.16 to -0.02, p=0.059; three studies, n=158). Patients who received cholinesterase inhibitors performed significantly faster on the Trail Making test part A (effect size -0.69, 95% CI -1.14 to -0.23, p=0.003; four studies, n=93) and showed significantly better results for memory (effect size 0.28, 95% CI 0.06 to 0.50, p=0.014; three studies, n=146). Positive symptoms on the PANSS analysis were significantly more intense with cholinesterase inhibitors (effect size 0.28, 95% CI 0.07 to 0.50, p=0.01; seven studies, n=364, more than 50% of data contributed by one study).
Statistical heterogeneity was found for the analysis of extrapyramidal symptoms and the negative PANSS subscale, but this was not further evaluated.