Engelhardt 1978.

Methods	Randomisation: “computer‐generated randomisation scheme”. Blinding: double‐blind. Duration: 24 weeks. Design: parallel. Location: Psychopharmacology Research Unit of the State University of New York, Downstate Medical Center. Setting: outpatients.
Participants	Diagnosis (study completers, N = 36): chronic undifferentiated schizophrenia (N = 24), paranoid schizophrenia (N = 12). N = 80. Gender: 22M, 14F. Age: mean 35.3 years. History: duration stable: not indicated, duration of illness: mean 11.66 years, number of previous hospitalisations: not indicated, age at onset: not indicated, severity of illness: not indicated, baseline antipsychotic dose: not indicated.
Interventions	1. Haloperidol: flexible dose, dose range: 1.25 mg to 25 mg/day, mean dose: 5.7 mg/day. N = 38. 2. Thiothixene: flexible dose, dose range: 5 mg to 60 mg/day, mean dose: 16.0 mg/day. N = 42. “ratio of mean thiothixene‐to‐haloperidol dosage: 2,8:1” Rescue medication: antiparkinson medication was allowed.
Outcomes	Examined: Clinically important response to treatment: Clinical Global Improvement Rating. Leaving the study early due to any reason. Leaving the study early due to adverse effects. Adverse Effects: at least one adverse effect, at least one movement disorder, tardive dyskinesia. Unable to use: Mental state general: Katz Adjustment Scales (no total score available). Mental state general: Lipman‐Rickels Self‐Rating Symptom Scale (SRSS) (no raw data available).
Notes	36 completers of the full 24 weeks. “4‐week placebo wash‐out period prior to active drug treatment.”
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	“Patients were assigned with a computer‐generated randomisation scheme stratified for sex and marital status.”
Allocation concealment (selection bias)	Unclear risk	No further details.
Blinding (performance bias and detection bias) (performance bias)	Low risk	“Double‐blind”. “Haloperidol and thiothixene were supplied in capsules of identical appearance.”
Blinding (performance bias and detection bias) (detection bias)	Unclear risk	“Double‐blind”. No further details.
Incomplete outcome data (attrition bias) All outcomes	High risk	Altogether 80 people with schizophrenia were assigned to treatment. “Of the 80 patients only 56 remained in treatment beyond the first 2 weeks.” Only 36 participants were able to remain in treatment for the full 24 weeks of the study period. So the overall‐attrition was high (44 of 80 participants; 55%). 22 of 38 participants (57.9%) left the trial early in the haloperidol‐group and 22 of 42 participants (52.4%) in the thiothixene‐group. The trial authors provided only completers‐analyses comprising altogether 36 participants.
Selective reporting (reporting bias)	High risk	The outcome data were not fully addressed (no raw data or total score regarding the Katz Adjustment Scales and SRSS). No information available regarding the number of participants who received a medication with antiparkinson drugs.
Other bias	High risk	Occurrence of baseline imbalances: the differences between the two treatment‐groups were statistically significant in terms of the mean age of the participants and the mean duration of the illness. Tobin 1980: "The test groups were not homogeneous at baseline. There was a significantly higher proportion of older, chronic patients with severe symptoms in the haloperidol group than in the thiothixene group."