Abstract: We identified 14 studies (16 reports) that met inclusion criteria for this review and involved 3077 randomised participants in total. Most of these studies included a mixed sample of participants; we obtained data for the subset of interest for this review (diagnosis of incurable cancer and receiving cancer treatment) from the study investigators of 12 studies, for which we included 535 participants in the subset meta-analysis for fatigue post intervention. Researchers investigated a broad range of psychosocial interventions with different intervention aims and durations. We identified sources of potential bias, including lack of description of methods of blinding and allocation concealment and inclusion of small study populations. Findings from our meta-analysis do not support the effectiveness of psychosocial interventions for reducing fatigue post intervention (standardised mean difference (SMD) -0.25, 95% confidence interval (CI) -0.50 to 0.00; not significant; 535 participants, 12 studies; very low-quality evidence). First follow-up findings on fatigue suggested benefit for participants assigned to the psychosocial intervention compared with control (SMD -0.66, 95% CI -1.00 to -0.32; 147 participants, four studies; very low-quality evidence), which was not sustained at second follow-up (SMD -0.41, 95% CI -1.12 to 0.30; not significant; very low-quality evidence). Results for our secondary outcomes revealed very low-quality evidence for the efficacy of psychosocial interventions in improving physical functioning post intervention (SMD 0.32, 95% CI 0.01 to 0.63; 307 participants, seven studies). These findings were not sustained at first follow-up (SMD 0.37, 95% CI -0.20 to 0.94; not significant; 122 participants, two studies; very low-quality evidence). Findings do not support the effectiveness of psychosocial interventions for improving social functioning (mean difference (MD) 4.16, 95% CI -11.20 to 19.53; not significant; 141 participants, four studies), role functioning (MD 3.49, 95% CI -12.78 to 19.76; not significant; 143 participants, four studies), emotional functioning (SMD -0.11, 95% CI -0.56 to 0.35; not significant; 115 participants, three studies), or cognitive functioning (MD -2.23, 95% CI -12.52 to 8.06; not significant; 86 participants, two studies) post intervention. Only three studies evaluated adverse events. These studies found no difference between the number of adverse events among participants in the intervention versus control group. Using GRADE, we considered the overall quality of evidence for our primary and secondary outcomes to be very low. Therefore, we have very little confidence in the effect estimate, and the true effect is likely to be substantially different from the estimate of effect. Limitations in study quality and imprecision due to sparse data resulted in downgrading of the quality of data. Additionally, most studies were at high risk of bias owing to their small sample size for the subset of patients with incurable cancer (fewer than 50 participants per arm), leading to uncertainty about effect estimates. We found little evidence around the benefits of psychosocial interventions provided to reduce fatigue in adult patients with incurable cancer receiving cancer treatment with palliative intent. Additional studies with larger samples are required to assess whether psychosocial interventions are beneficial for addressing fatigue in patients with incurable cancer.

Plain-language summary: In November 2016, we searched for clinical trials looking at psychological therapies in patients with incurable cancer receiving cancer treatment. We found 14 small studies of very low quality reporting data on tiredness outcomes, 12 of which provided data for analyses. A limited number (three studies) reported results about side effects; these studies investigated a psychological therapy combined with medication. Review authors found no support for the effectiveness of psychological therapies in reducing tiredness when assessed directly following the intervention. Very low-quality evidence suggests that psychological therapies may improve physical functioning directly after the intervention and may improve tiredness at first follow-up. Evidence shows no support for the effectiveness of psychosocial therapies in improving other domains of functioning. Limited evaluation of potential harm suggests no differences in side effects between patients receiving psychological therapy and those given usual care. Limited good quality evidence allows no conclusions on the use of psychological therapies in people with incurable cancer. Larger, high-quality trials are needed to find out whether psychological therapies help reduce tiredness for people with incurable cancer during cancer treatment. We rated the quality of study evidence using four levels: very low, low, moderate, and high. Very low-quality evidence means that we are very uncertain about the results. High-quality evidence means that we are very confident in the results. Included studies had design problems and included a very small number of participants. Therefore, the quality of the evidence in this review is very low, and results of this review should be interpreted with caution.