Nordentoft‐Denmark.

Methods	Allocation: randomised Blinding: not blinded (independent assessors aware of treatment allocation) Setting: Copenhagen and Aarhus County, Denmark (inpatient and outpatient mental health services) Inclusion criteria: met criteria for schizotypal disorder (ICD‐10) Exclusion criteria: antipsychotic medication for >12 weeks, psychiatric symptoms due to organic condition Duration: 24 months
Participants	Diagnosis: schizotypal disorder (ICD‐10) N = 79 Sex: men and women, ˜70:30% M:F Age: average ˜25 SD 5 years History: no details
Interventions	1. Integrated treatment: modified Assertive Community Treatment model with case load and home visits, group or individual social skills training, psycho‐education in multiple‐family groups: N = 42 2. Standard treatment: standard mental health service routines in Copenhagen and Aarhus: N = 37 There were no specific guidelines for providing antipsychotic medication to patients with schizotypal disorder, medication was prescribed by psychiatrist responsible for treatment
Outcomes	Transition to psychosis (ICD‐ 10) Leaving the study early Mental state: SAPS, SANS
Notes	Funding: Danish Ministry of Health (jr.nr. 96‐0770‐71), The Danish Ministry of Social Affairs, The University of Copenhagen, The Copenhagen Hospital Corporation, The Danish Medical Research Council (jr.nr. 9601612 and 9900734), and Slagtermester Wørzners Foundation. Power, sample size calculation: Quote: "Using Pocock’s formula (Pocock, 1996), we calculated that 39 patients were required for each study group to show a difference in transition rate of 10% compared with 40%. Thus, the study only has statistical power to detect large differences in transition rate". Adherence: see Table 14
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "Randomisation will be centralised and computerised with concealed randomisation sequence carried out by the Copenhagen Trial Unit (CTU)."
Allocation concealment (selection bias)	Unclear risk	Quote: "Randomisation will be centralised and computerised with concealed randomisation sequence carried out by the Copenhagen Trial Unit (CTU)." Ratio of 1:1 in blocks of 6, and stratified for each centre.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Quote: "The allocations concealment is ensured by the investigators call to the randomisation unit, CTU, after completing the collection of baseline data and data needed for the randomisation." Comment: precise method of allocation concealment was not described.
Blinding of outcome assessment (detection bias) All outcomes	High risk	Not blinded
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Assessors not blinded for treatment allocation
Selective reporting (reporting bias)	Unclear risk	Out of 79 randomised participants, 14 discontinued the study (attrition 18%). Attrition rates per group were 14% (N = 6) in integrated treatment group and 22% (N = 8) in standard treatment group. While treatment group, treatment site, gender, age, abuse of alcohol or drugs, psychotic, negative or disorganised symptoms at entry were not associated with study discontinuation, there was a significant association within participants who reported use of cannabis at least monthly at entry compared to those who reported no or less frequent use (37.5% versus 12.7%, P = 0.02). No details for study discontinuation reported.
Other bias	Low risk	All outcomes mentioned in publication methods reported. However, compared to registered protocol for the OPUS study, most of the outcomes relevant for this population of participants were reported except: suicidal behaviour, user satisfaction, adherence to treatment, compliance with medication.