Selection criteria
We included all randomised clinical trials (RCTs) comparing early warning signs interventions plus treatment as usual to treatment as
usual for people with schizophrenia or other non-affective psychosis
Data collection and analysis
We assessed included studies for quality and extracted data. If more than 50% of participants were lost to follow-up, the study was
excluded. For binary outcomes, we calculated standard estimates of risk ratio (RR) and the corresponding 95% confidence intervals
(CI), for continuous outcomes, we calculated mean differences (MD) with standard errors estimated, and for time to event outcomes
we calculated Cox proportional hazards ratios (HRs) and associated 95 % CI. We assessed risk of bias for included studies and assessed
overall study quality using the GRADE approach.