Background The impact of clinically assisted hydration on quality of life or survival in the last days of life is not known. A previous systematic review evaluated only trial data, mostly from studies focusing on patients in the last weeks of life, and found insufficient evidence to draw firm conclusions. This issue is often highly emotive. Practice varies significantly worldwide.

Aim To review the published evidence concerning assisted hydration in the final days of life, focusing on symptoms, side effects, survival, quality of life, and the views of patients and families.

Design Systematic literature review and narrative synthesis of studies using a range of methods. Databases were searched up to September 2019 alongside reference and journal hand searches. Research quality was appraised using Gough’s ‘Weight of Evidence’ framework.

Results The search yielded 4053 studies. Of the 27 papers included in the synthesis, only one study was judged to be of high quality and relevance. Most studies demonstrated little or no impact of clinically assisted hydration on quality of life, symptoms, or survival: many were poorly designed or underpowered. Of the ten studies investigating delirium, four (including the only high quality study) suggested an association between clinically assisted hydration and lower rates or delayed onset of delirium.

Conclusion There is insufficient evidence to draw conclusions on the impact of clinically assisted hydration on quality of life in the last days of life. Further research should focus on populations who are in the very final days of life. There is a lack of studies in non-cancer populations, and a lack of evidence relating to communication with patients and families about this uncertain area of clinical practice.