| Methods |
Design: three group parallel trial
Purpose: examine the effect of cognitive behaviour therapy on positive symptoms in patients with chronic schizophrenia |
| Participants |
Patients: people with chronic schizophrenia
Baseline comparability: yes |
| Interventions |
Placebo: sessions of supportive counselling
Untreated: no sessions
Experimental: sessions of behavioural cognitive therapy
(Co‐intervention: standard care including medication, fixed dose) |
| Outcomes |
Number of patients with improvement of positive symptoms by 50% or more
Mean number and intensity of positive psychotic symptoms on Present state examination and Brief psychiatric rating scale |
| Notes |
|
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Adequate sequence generation? |
Unclear risk |
'stratified block randomised procedure' |
| Allocation concealment? |
Low risk |
'sealed envelopes' ... ' carried out by a third party' |
| Blinding?
Treatment provider |
High risk |
Not described as double‐blind (placebo/behavioural cognitive therapy) |
| Blinding?
Outcome assessor |
Low risk |
'Effort was made to blind the independent assessors...' ... '... suggesting that blinding was satisfactory' |
| Incomplete outcome data addressed?
All outcomes |
Low risk |
Drop‐out < 15% |
| Free of selective reporting? |
Unclear risk |
No protocol available |
| Free of other bias? |
Low risk |
|
| No signs of variance inequality or skewness? |
Unclear risk |
Not relevant (binary outcome) |
| Trial size > 49? |
Low risk |
N = 54 |
| Clearly concealed allocation + trial size > 49 + drop‐out max 15% |
Low risk |
All three categories fulfilled |
