| Methods |
RCT, USA. Pts were chronically hospitalised patients. |
| Participants |
12 smokers with DSM‐IIIR diagnosis of chronic schizophrenia. All pts had persistent psychopathology despite extended course of typical antipsychotics.
Interest in quitting smoking was uncertain. No TQD set.
8 males; mean age 34; average CPD 7. Average length of illness 16 yrs. |
| Interventions |
1. Low clozapine (dose varied but plasma clozapine level 50‐150ng/ml) for 12 wks
2. Medium clozapine (plasma level 200‐300 ng/ml) for 12 wks
3. High clozapine (plasma level 350‐450 ng/ml) for 12 wks
No other additional intervention for all groups. |
| Outcomes |
Abstinence was not defined or measured.
Reduction of smoking measured by number of cigarettes smoked and expired CO level. Measurements taken at baseline and wk 12.
Effects on mental state measured by BPRS and CGI. |
| Source of funding |
Not reported |
| Primary aim of the study |
Efftect of different doses of clozapine on mental state |
| Notes |
Pts were allowed free access to cigarettes for 120 minutes only. |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
Unclear risk |
The method of sequence generation was not described. |
| Allocation concealment (selection bias) |
Unclear risk |
No description of allocation concealment in the reports. |
| Blinding (performance bias and detection bias)
All outcomes |
Unclear risk |
Not stated |
| Incomplete outcome data (attrition bias)
All outcomes |
Unclear risk |
Not stated |
| Selective reporting (reporting bias) |
Low risk |
All expected outcomes |
| Other bias |
High risk |
Potential baseline difference between groups: the low clozapine group had lower baseline expired CO level. |
