Gonzalez‐Pinto 2004.

Study characteristics
Patient sampling	Prospective, consecutive.
Patient characteristics and setting	N with a clinical diagnosis of psychosis: 112. N screened: 112. Age: mean age 28.86 (SD 10.27), range 16‐61. Gender: M 75, F 37. Ethnicity: Not reported. Comorbid disorders: Not reported. Duration of symptoms: Not reported. Concurrent medications used: Not reported. Inclusion criteria: Presenting with first psychotic episode (FPE) and needing in‐patient psychiatric treatment. Aged 15–65 years. Exclusion criteria: Participants with mental retardation, organic brain disorders or drug abuse as a primary diagnosis. Study aim: To investigate the association between age and the occurrence of FRS in patients with a first psychotic episode (FPE) and to look for a linear relationship between age and number of FRS. Previous treatment for schizophrenia: None. Clinical setting: Inpatients. Country: Spain.
Index tests	Description of FRS used: FRS using a checklist of 11 items: audible thoughts, voices arguing, voices commenting, delusional perception, somatic passivity, made thoughts, made impulses, made volition, made feelings, thought withdrawal and thought broadcasting. Professionals performing test: Two psychiatrists. Resolution of discrepancies: Not reported. How FRS used in study: Prevalence.
Target condition and reference standard(s)	Reference standard: DSM‐IV using the Structured Clinical Interview for DSM Disorders (SCID‐1). Performed once a year over three years. Diagnosis made at three years considered the definitive diagnosis. If follow‐up not available, last diagnosis used. Also considered information from clinical records, family informants and staff observations. Target condition(s): 1. Schizophrenia. 2. Bipolar disorder (I or II). 3. Other diagnosis (includes schizophreniform disorder, schizoaffective disorder, delusional disorder, brief psychotic disorder, atypical psychosis, or major depressive disorder with psychotic symptoms (with no history of manic or hypomanic episode). Professionals performing test: Two psychiatrists. Resolution of discrepancies: Not reported. Kappa = 0.88 for inter‐rater reliability of SCID‐I diagnoses.
Flow and timing	Study process: The day after admission, patients were assessed with a protocol that included SCID‐I and FRS. The evaluations were performed during a clinical interview lasting about 90 min and pertaining to the previous week. Patients were evaluated by direct interview, with the same methodology, once a year over a period of 3 years. Follow‐up: 3 years.
Comparative
Notes
Methodological quality
Item	Authors' judgement	Risk of bias	Applicability concerns
DOMAIN 1: Patient Selection
Was a consecutive or random sample of patients enrolled?	Yes
Was a case‐control design avoided?	Yes
Did the study avoid inappropriate exclusions?	Unclear
		Low	Low
DOMAIN 2: Index Test All tests
Were the index test results interpreted without knowledge of the results of the reference standard?	Unclear
Did the study pre‐specify whether they were using one or multiple FRSs?	Yes
		Unclear	High
DOMAIN 3: Reference Standard
Is the reference standards likely to correctly classify the target condition?	Yes
Were the reference standard results interpreted without knowledge of the results of the index tests?	Unclear
		Unclear	Low
DOMAIN 4: Flow and Timing
Was there an appropriate interval between index test and reference standard?	Yes
Were all patients included in the analysis?	Yes
Did all patients receive a reference standard?	Yes
Did all patients receive the same reference standard?	Yes
Did all patients receive an index test?	Yes
Did all patients receive the same index test?	Yes
		Low