Summary of findings 3. Cognitive behavioural therapy versus standard care for both severe mental illness and substance misuse.
| COGNITIVE BEHAVIOUR THERAPY compared to STANDARD CARE for both severe mental illness and substance misuse | ||||||
| Patient or population: people with both severe mental illness and substance misuse Settings: outpatient Intervention: COGNITIVE BEHAVIOUR THERAPY Comparison: STANDARD CARE | ||||||
| Outcomes | Illustrative comparative risks* (95% CI) | Relative effect (95% CI) | No of Participants (studies) | Quality of the evidence (GRADE) | Comments | |
| Assumed risk | Corresponding risk | |||||
| STANDARD CARE | COGNITIVE BEHAVIOUR THERAPY | |||||
| Leaving the study early: Lost to treatment Follow‐up: mean 3 months | 97 per 1000 | 108 per 1000 (43 to 277) | RR 1.12 (0.44 to 2.86) | 152 (2 studies) | ⊕⊕⊝⊝ low1,2 | |
| Adverse event: Death | See comment | See comment | Not estimable | See comment | Death was not measured in any of the trials. | |
| Substance use: Alcohol | See comment | See comment | Not estimable | See comment | See comment | Naeem 2005 measured alcohol together with drug use in the Health of the Nation Outcome (HoNOS) scale. Edwards did not report on alcohol. |
| Substance use: Drug (Cannabis) Percentage of participants who used cannabis in last 4 weeks Follow‐up: mean 6 months | 500 per 1000 | 650 per 1000 (395 to 1000) | RR 1.30 (0.79 to 2.15) | 47 (1 study) | ⊕⊝⊝⊝ very low1,3 | Data for other drugs were skewed and were not compared between intervention and control. |
| Mental state: average score (Insight scale) Follow‐up: by 3 months | The mean mental state in the intervention groups was 0.52 higher (0.78 lower to 1.82 higher) | 105 (1 study) | ⊕⊕⊝⊝ low1,3 | The difference noted is unlikely to be clinically important | ||
| Social functioning: Average score* The Social and Occupational Functioning Scale (SOFAS): scale of 1 to 100 Follow‐up: mean 6 months | The mean global assessment of functioning in the intervention groups was 4.70 lower (14.52 lower to 5.12 higher) | 47 (1 study) | ⊕⊝⊝⊝ very low1,4 | * Global state data were not reported by the trials The other trial in this comparison (Naeem 2005) measured Functioning with the HoNOS scale. Data were skewed and meta‐analysis was not possible |
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| Quality of life/ life satisfaction | See comment | Not estimable | See comment | No study measured Quality of life | ||
| *The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: Confidence interval; RR: Risk ratio; | ||||||
| GRADE Working Group grades of evidence High quality: further research is very unlikely to change our confidence in the estimate of effect. Moderate quality: further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate. Low quality: further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate. Very low quality: we are very uncertain about the estimate. | ||||||
1 Risk of bias: Rated as SERIOUS: The participants and personnel were not blinded and performance bias may be present. Missing data were addressed by Last Observation Carried Forward in Edward 2006 but attrition bias may be present as loss to follow‐up was 30% at 9 months. 2 Imprecision: Rated as SERIOUS: The event rate is low and the confidence interval is wide. 3 Imprecision: Rated as VERY SERIOUS: The event rate is low, the sample size small and the confidence interval is wide. 4 Imprecision: Rated as VERY SERIOUS: The confidence interval is very wide and the sample size small.