Daradkeh 1995.

Study characteristics
Patient sampling	Retrospective, selected from a previous sample.
Patient characteristics and setting	N included in study: 168. N in analysis: 168. Age: Mean age onset 26.8 years (SD = 9.3) Gender: M 108, F 60. Ethnicity: Not reported. Comorbid disorders: Not reported. Duration of symptoms: Not reported. Concurrent medications used: Not reported. Inclusion criteria: Patients with major mental illnesses. Exclusion criteria: Not reported. Study aim: Prevalence and diagnostic validity of FRS for schizophrenia.. Previous treatment for schizophrenia: Not reported. Clinical setting: Unclear. Country: United Arab Emirates.
Index tests	Description of FRS used: FRS's assessed through OPCRIT. 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: ICD‐10 through OPCRIT. Target condition(s): Schizophrenia. Professionals performing test: Pair of clinicians. Resolution of discrepancies: Not reported.
Flow and timing	Study process:Patients selected from a larger previous trial of ICD‐10. Most patients assessed by pairs of clinicians and two thirds had diagnostic interviews applied. OPCRIT was used to generate diagnosis and FRSs. Follow‐up: Not reported.
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?	No
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?	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