Randomisation and masking
psychosis
BLIND
Once all participants in a practice were recruited and baseline data were collected, we assigned the practice to the PARTNERS intervention or care as usual (control) at a 1:1 allocation, using a computer-generated minimisation algorithm, with allocation minimised on geographical area and estimated practice psychosis population size, according to the QOF register. Allocation was undertaken by a Clinical Trials Unit researcher not involved in delivery or analysis of the trial, and communicated to the practice and participants by letter or preferred method of contact.It was not possible to blind staff in the general practice or the participants because of the nature of the psychosocial intervention. Researchers conducting follow-up assessments were not blinded for logistical reasons, as they were responsible for maintaining relationships with intervention practitioners and general practices. Statisticians were masked to allocation during primary analyses.