Between 15 and 40% of cancer patients develop clinical anxiety and/or depression (Derogatis et al, 1983;Massie and Holland, 1990;Parle et al, 1996). Even for those ostensibly cured the prevalence remains appreciably higher than that of the general population a year or more after diagnosis (Devlen et al, 1987). This evidence, combined with significant pressure from service users, has led to increasing provision of psychological interventions in British oncology services. This has been piecemeal (Fallowfield, 1988) and guided more by local factors than evidence of efficacy. There is little evidence based consensus about optimal methods of intervention, appropriate standards for clinical practice and training, or whether service provision is best directed towards prevention or the treatment of disorder (Fallowfield and Roberts, 1992;Hopwood and Maguire, 1992;Brennan and Sheard, 1994).The impact of psychological interventions in oncology on psychosocial, disease, symptom and treatment side-effect outcomes has been evaluated in a relatively large number of trials which vary considerably in their research questions, methodology, settings and results. Meyer and Mark (1995) aggregated all psychological outcomes for 45 such trials and reported a small mean effect size of 0.24 standard deviations for a single aggregate measure of psychological outcome. Their broad entry criteria ensured the inclusion of a large number of trials but the resulting extreme heterogeneity in terms of diversity of research questions and outcome measures render the meaning of this aggregate finding difficult to assess. We conducted, therefore, two metaanalyses of trials of interventions which sought to treat or prevent anxiety and/or depression. The relevance of the findings to clinical practice and service provision is assessed.
METHODS
Identical methods were used for the two meta-analyses
Search strategyMedline, PsycLit and BIDS social sciences computerized databases were searched using the using the keywords cancer, counselling, psychotherapy, psychological therapy, group support/therapy, relaxation, imagery and visualization. Citations in identified papers and reviews (Watson, 1983;Cunningham, 1988;Vachon, 1988;Harman, 1991;Andersen, 1992;Trijsburg et al, 1992), Aslib. index to theses (keywords cancer, counselling and psychotherapy), and Comprehensive Dissertation Abstracts: Psychology (keyword cancer) were manually searched.
SummaryThe findings of two meta-analyses of trials of psychological interventions in patients with cancer are presented: the first using anxiety and the second depression, as a main outcome measure. The majority of the trials were preventative, selecting subjects on the basis of a cancer diagnosis rather than on psychological criteria. For anxiety, 25 trials were identified and six were excluded because of missing data. The remaining 19 trials (including five unpublished) had a combined effect size of 0.42 standard deviations in favour of treatment against no-treatment controls (95% confidence interval (CI) 0.08-0.74, ...