Harding, R., List, S., Epiphaniou, E., & Jones, H. (2012). How can informal caregivers in cancer and palliative care be supported? An updated systematic literature review of interventions and their effectiveness. Palliative Medicine, 26, 7–22.

To update and evaluate intervention studies and current state of the science regarding support for caregivers in a systematic review

• Databases used in the search were MEDLINE, CINAHL, and PsycINFO.
• Key words were carer; caregiver; cancer; palliative; end of life; and terminal.
• To be included in the review, studies had to involve adult caregivers/adult recipients, be English language, occur in the cancer palliative care setting, and be intervention-based (from 2001 to July 2010).
• Articles reporting case studies, interventions without evaluation data, and interventions during the bereavement phase, as well as articles included in Harding and Higginson's 2003 systematic review paper, were excluded.

• The search revealed a total of 10,817 references.
• Studies were evaluated using the Jadad Rating Scale and the Quality Rating Scale.
• Despite the exclusion of bereavement studies, multiple studies are included in table and summarized.
• An international sample of studies was represented.
• Despite intent to focus on cancer populations, nine studies were in palliative care (not clearly cancer); a few studies were based on program implementation (process), so no specific caregiver outcomes were reported.

• A total number of 33 studies were included in the review. 
• Sample range of subjects across studies was 2–2,000+ (less than 25 [n = 10]; 25–100 [n = 10]; more than 100 [n = 13]).
• Interventions were dyad (n = 16) or caregiver only (n = 17).

• End-of-life phase
• Palliative care

Group interventions were studied most often, although only two of the studies included reported a statistically significant benefit compared to controls. The next largest group of studies investigated one-on-one psychological interventions. Two of these showed a positive effect for patient/carer dyads. Overall findings were equivocal, with about the same number of studies showing significant improvement with the intervention as those showing no change or difference between groups. The nature and timing of interventions varied greatly across studies included.

The authors identified seven categories of interventions: (a) one-on-one psychological, (b) dyad psychological, (c) palliative care/hospice (delivery), (d) informational/training, (e) respite, (f) group intervention, and (g) physical.

Given the limitations, differences in the nature of interventions reviewed, and inconsistencies of findings across studies, this review does not provide strong support for any particular type of intervention.

This summary has limited guidance due to lack of synthesis to actually guide practice. There were also inconsistencies between the inclusion and exclusion criteria and the studies reported; not all have clear implications to cancer, affect active information caregivers, or measure caregiver outcomes.