Prehabilitation in elective abdominal cancer surgery in older patients: systematic review and meta-analysis.

Prehabilitation has emerged as a strategy to prepare patients for elective abdominal cancer surgery with documented improvements in postoperative outcomes. The aim of this study was to assess the evidence for prehabilitation interventions of relevance to the older adult. Systematic searches were conducted using MEDLINE, Web of Science, Scopus, CINAHL and PsychINFO. Studies of preoperative intervention (prehabilitation) in patients undergoing abdominal cancer surgery reporting postoperative outcomes were included. Age limits were not set as preliminary searches revealed this would be too restrictive. Articles were screened and selected based on PRISMA guidelines, and assessment of bias was performed. Qualitative, quantitative and meta-analyses of data were conducted as appropriate. Thirty-three studies (3962 patients) were included. Interventions included exercise, nutrition, psychological input, comprehensive geriatric assessment and optimization, smoking cessation and multimodal (two or more interventions). Nine studies purposely selected high-risk, frail or older patients. Thirty studies were at moderate or high risk of bias. Ten studies individually reported benefits in complication rates, with meta-analyses for overall complications demonstrating significant benefit: multimodal (risk difference -0·1 (95 per cent c.i. -0·18 to -0·02); P = 0·01, I2  = 18 per cent) and nutrition (risk difference -0·18 (-0·26 to -0·10); P