|Group cognitive behavioural therapy for schizophrenia: a systematic review of the literature
|Lawrence R, Bradshaw T, Mairs H
The review concluded that, although positive results have been reported for cognitive-behavioural group therapy, these are not consistent between studies and the methodological weaknesses of the studies compromise the results. The authors appropriately considered the methodological weaknesses and differences across the studies, and their cautious conclusions appear appropriate based on the evidence presented.
To evaluate the effectiveness of cognitive-behavioural group therapy (CBGT) for the treatment of schizophrenia.
MEDLINE, PsycINFO, CINAHL, EMBASE, the Cochrane Library, National Research Register and SIGLE were searched from 1993 for studies reported in English; the search terms were reported. Several relevant journals and the bibliographies of retrieved papers were also screened for additional studies. Experts in the field were contacted for any unpublished or in-progress studies.
Controlled pre-test post-test studies of CBGT for the treatment of individuals (not family or carers) aged 16 years or older with a diagnosis of schizophrenia or a schizoaffective disorder, where outcomes were measured using standardised validated measures, were eligible for inclusion. The included studies varied in terms of the methods used to diagnose schizophrenia, the intervention evaluated, the comparator used and the outcome measures reported (details provided in the review). Sessions lasted 1 or 2 hours and were provided for between 6 and 12 weeks. Most of the participants were male (46.5 to 81.3%). Details of the participants and interventions were poorly reported in the included studies.
The authors did not state how the papers were selected for the review, or how many reviewers performed the selection.
Assessment of study quality
Validity was assessed using criteria based on the NHS Centre for Reviews and Dissemination's guidance (Report 4, 2001), which considers study design, sample selection, sample size, blinding of the assessors, data analysis, follow-up, adherence to diagnostic criteria and non-specific effects of group therapy.
Three reviewers independently assessed validity.
Three reviewers independently extracted data on the numbers of patients experiencing an outcome in each arm of a study.
Methods of synthesis
The studies were combined in a narrative, with additional descriptive information presented in the tables.
Results of the review
Five studies (n=255) were included in the review: three were randomised controlled trials and two were classified as repeated measures studies.
Sample sizes in all studies were small (range: 20 to 88) and none of the studies reported a power calculation. Attrition was high (9.4 to 31.8%) and was not explained in most studies, and an intention-to-treat analysis infrequently used. Only one study reported allocation concealment, but no attempts were made to maintain or monitor the blinding of outcome assessors.
After CBGT, statistically significant benefits were reported in terms of social anxiety (2 studies), auditory hallucinations (1 study), symptoms (1 study), general psychiatric pathology (2 studies), depression (2 studies), insight (1 study), social functioning (1 study), compliance (1 study), client satisfaction (1 study) and Brief Psychiatric Rating Scale scores (1 study). Many of the positive results were not maintained at follow-up: the results were not consistent across studies as no significant benefit of CBGT was reported for auditory hallucinations (1 study), relapse and rehospitalisation (1 study), and symptoms (1 study).
Although positive results have been reported for CBGT, these are not consistent between studies and the methodological weaknesses of the studies compromise the results.
The inclusion criteria were clear in terms of the interventions, participants, outcomes and study designs. Several relevant sources were searched and authors attempted to locate unpublished data, thereby reducing the risk of publication bias. However, the restriction to studies reported in English might have resulted in the loss of some relevant data. Methods were used to minimise reviewer error and bias in the assessment of validity and extraction of data, but it was not clear whether similar steps were taken at the study selection stage. Validity was assessed using established criteria and methodological limitations of the included studies were discussed in the text of the review. In view of the differences between the studies, a narrative synthesis was appropriate. Characteristics of the included studies were presented in the tables. In general, the review reported only whether a study showed positive or negative results; the raw data on which these statements were based were reported for few outcomes. The included studies were conducted in Australia (2 studies), England (2 studies) and Germany (1 study) and, given the variation in practices between countries, the results from these studies may not be generalisable to other national health systems. The included studies were generally poor quality, with small sample sizes and high attrition rates. The authors appropriately considered the methodological weaknesses of the included studies and differences across the studies. Consequently, their cautious conclusions appear appropriate based on the evidence presented.
Implications of the review for practice and research
Practice: The authors did not state any implications for practice.
Research: The authors stated that further well-conducted studies are needed to investigate the potential of CBGT in enhancing access to evidence-based psychological therapy and social networks, and to evaluate psychoeducational interventions.
Lawrence R, Bradshaw T, Mairs H. Group cognitive behavioural therapy for schizophrenia: a systematic review of the literature. Journal of Psychiatric and Mental Health Nursing 2006; 13(6): 673-681
Subject indexing assigned by NLM
Adult; Cognitive Therapy /organization & Evidence-Based Medicine; Patient Readmission; Psychotherapy, Group /organization & Randomized Controlled Trials as Topic; Recurrence; Research Design; Sample Size; Schizophrenia /diagnosis /therapy; Schizophrenic Psychology; Self-Help Groups /organization & Single-Blind Method; Treatment Outcome; administration; administration; administration
Date bibliographic record published
Date abstract record published
This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.