Chopra 1987.

Study characteristics
Patient sampling	Prospective and consecutive.
Patient characteristics and setting	N included in study: 50. N in analysis: 50. Age: Mean not reported. Range 21‐86 years. Gender: M 23, F 27. Ethnicity: Not reported. Comorbid disorders: Not reported. Duration of symptoms: Not reported. Concurrent medications used: Not reported. Inclusion criteria: Not reported. "All the patients, irrespective of their diagnosis, were interviewed ... after admission" to the psychiatric hospital. Exclusion criteria: Not reported. Study aim: To evaluate the prevalence and diagnostic implications of FRS. Previous treatment for schizophrenia: Not reported. Clinical setting: Inpatients. Country: Australia.
Index tests	Description of FRS used: Questionnaire specially prepared for the study and based on Mellor's definitions of the FRS. Professionals performing test: Not reported. Resolution of discrepancies: Not reported. How FRS used in study: Prevalence and diagnosis.
Target condition and reference standard(s)	Reference standard: DSM‐III. Target condition(s): Schizophrenic disorders, psychotic disorders not elsewhere classified (schizophreniform disorder, brief reactive psychosis, schizoaffective disorder, atypical psychosis‐schizophrenia onset after age 45), affective disorders (mania, major depression recurrent, atypical depression, dysthymic disorder), organic mental disorders, anxiety disorders, adjustment disorders and personality disorders. Professionals performing test: Not reported. Resolution of discrepancies: Not reported. The second author confirmed all diagnoses.
Flow and timing	Study process: All the patients, irrespective of their diagnosis, were interviewed by one of the authors (MG) for the presence of FRS as early as possible after admission. The patients were later seen by the first author (HDC) to confirm the findings and diagnosis. Diagnostic labels were given according to DSM‐III. Follow‐up: Not reported. Exclusions: Exclusions not explicitly reported in the study.
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?	Unclear
Did the study avoid inappropriate exclusions?	Unclear
		Unclear	Unclear
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?	No
		Unclear	Low
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?	Unclear
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