Preiser 1979.

Study characteristics
Patient sampling	Prospective, consecutive.
Patient characteristics and setting	N included in study: 88. N in analysis: 88. Age: Not reported for whole sample. (Schizophrenic with FRS: mean 25.6 years. Schizophrenic without FRS: mean 23.3 years). Gender: Not reported for whole sample. (Schizophrenic with FRS: M13, F12. Schizophrenic without FRS: M14, F13). Ethnicity: Not reported for whole sample. (Schizophrenic with FRS: Black 14, White 7, Hispanic 4. Schizophrenic without FRS: Black 17, White 8, Hispanic 2). Comorbid disorders: Not reported. Duration of symptoms: Not reported. Concurrent medications used: Majority of patients were on medication, medications not reported. Inclusion criteria: The study was conducted on a 24‐bed therapeutic community ward in a large municipal hospital. Patients were mostly referred from the acute wards of the psychiatric hospital, sample consisted of patients who were judged to need hospitalisation of at least 2 weeks duration and to have the potential to profit from the intensive therapeutic experience offered. Exclusion criteria: Not reported. Study aim: To investigate whether schizophrenics with FRS have more observable pathologic behaviour than schizophrenics without FRS and whether schizophrenics with FRS have a poorer response to an intensive short‐term treatment program than schizophrenics without FRS. Previous treatment for schizophrenia: Not reported, majority of patients were medicated and referred from the acute wards of the hospital. Clinical setting: Inpatients. Country: USA.
Index tests	Description of FRS used: FRS as defined by Mellor. Professionals performing test: Each patient's therapist and corroborated by a senior attending psychiatrist. Resolution of discrepancies: Not reported. How FRS used in study: Prognosis.
Target condition and reference standard(s)	Reference standard: Bleulerian and/or ego function criteria at discharge from the ward. Target condition(s): Schizophrenia and not schizophrenia (not defined in study). Professionals performing test: Individual therapist in consultation with the attending supervisor. Resolution of discrepancies: Not reported.
Flow and timing	Study process: During a 6‐month period all patients admitted to the ward were evaluated through a nurse completing Psychotic Inpatient Profile (PIP), and therapist's evaluation through a scale . FRS were assessed during patients time on the ward and diagnosis was decided at discharge. Maximum stay on the ward was 3 months and the average stay was 6 weeks. Follow‐up: Not reported. Exclusions: "Five patients not diagnosed schizophrenic also exhibited FRS. These patients were not included in any of the subsequent analyses reported in this study."
Comparative
Notes	Unclear whether all patients received the index test; 88 patients were included, "52 were given a discharge diagnosis of schizophrenia. Of these 52, 25 exhibited at least one Schneiderian first‐rank symptom, and 27 exhibited none. Five patients not diagnosed schizophrenic also exhibited FRS. These patients were not included in any of the subsequent analyses reported in this study."
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?	Yes
Did the study pre‐specify whether they were using one or multiple FRSs?	No
		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	Unclear
DOMAIN 4: Flow and Timing
Was there an appropriate interval between index test and reference standard?	Unclear
Were all patients included in the analysis?	Unclear
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
		Unclear