Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
Symptom severity
Systematic review	370 people 4 RCTs in this analysis	Proportion of people who improved 6 to 12 weeks with clozapine with standard antipsychotic drugs Absolute results not reported	RR for no improvement compared with standard antipsychotic drugs 0.71 95% CI 0.64 to 0.79	Small effect size	clozapine
Systematic review	648 people 2 RCTs in this analysis	Proportion of people who improved 12 to 24 months with clozapine with standard antipsychotic drugs Absolute results not reported	RR for no improvement compared with standard antipsychotic drugs 0.83 95% CI 0.76 to 0.91	Small effect size	clozapine