Stephens 1980.

Study characteristics
Patient sampling	Retrospective, randomly selected.
Patient characteristics and setting	N included in study: 555. N in analysis: 120. Age: Mean age 35.4 (range 20‐57). Gender: M 60, F 60. Ethnicity: Not reported. Comorbid disorders: Not reported. Duration of symptoms: Not reported. Concurrent medications used: Phenothiazine alone and treatment with a phenothiazine combined with a tricyclic antidepressant or antianxiety drug. Inclusion criteria: Newly hospitalised patients who had participated in three drug studies between 1964 and 1966. Exclusion criteria: Patients with brain syndromes, major systemic diseases, mental deficiency, and alcoholism or drug abuse. Study aim: Prognostic implications of diagnostic criteria. Previous treatment for schizophrenia: Hospitalisation. Clinical setting: Inpatients. Country: USA.
Index tests	Description of FRS used: Not reported. Professionals performing test: Not reported. Resolution of discrepancies: Not reported. How FRS used in study: Diagnosis.
Target condition and reference standard(s)	Reference standard: DSM‐II*. Target condition(s): Schizoprenia (chronic undifferentiated, paranoid, acute undifferentiated), schizoaffective, psychotic depression. Professionals performing test: Not reported. Resolution of discrepancies: Not reported.
Flow and timing	Study process: 555 newly hospitalised patients admitted over 2 years were participants in previous drug studies. 120 participants were randomly selected. Retrospective diagnoses made by chart review using six sets of criteria including FRS. The seventh diagnosis was made at the time of hospitalisation using DSM‐II. Follow‐up: Mean 9.8 years Exclusion: All included participants in analyses. Followup data that is not relevant for this review was obtained for 82 participants, reasons for exclusions not provided.
Comparative
Notes	*Also reported diagnoses using the New York Research Diagnostic Criteria (RDC), the New Haven Schizophrenia Index (NHSI), the 12‐point “Flexible” criteria system developed by the Washington field center of the International Pilot Study of Schizophrenia (Carpenter et al., 1973) the St. Louis diagnostic criteria (Feighner et al., 1972) and the modification by Bland and Orn (1979) of the St. Louis criteria.
Methodological quality
Item	Authors' judgement	Risk of bias	Applicability concerns
DOMAIN 1: Patient Selection
Was a consecutive or random sample of patients enrolled?	Unclear
Was a case‐control design avoided?	Yes
Did the study avoid inappropriate exclusions?	Yes
		Unclear	Unclear
DOMAIN 2: Index Test All tests
Were the index test results interpreted without knowledge of the results of the reference standard?	Yes
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?	Unclear
Were the reference standard results interpreted without knowledge of the results of the index tests?	Yes
		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