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. |
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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. |
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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. |
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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). |
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Notes | 36 completers of the full 24 weeks. “4‐week placebo wash‐out period prior to active drug treatment.” |
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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." |