It is very uncertain whether telephone quitline referral changes quitline referral vs control compared with no treatment or usual care (very low certainty).
It is very uncertain whether telephone quitline referral changes health system telephone counselling vs quitline compared with no treatment or usual care (very low certainty).
Exercise‐based cardiac rehabilitation showed no clear difference in all‐cause mortality compared with usual care (low certainty).
Exercise‐based cardiac rehabilitation probably leads to lower all‐cause hospital admissions compared with usual care (moderate certainty).
Exercise‐based cardiac rehabilitation showed no clear difference in HF‐related hospital admissions compared with usual care (moderate certainty).
It is very uncertain whether preoperative parenteral nutrition changes non‐infectious complications compared with usual care or control (very low certainty).
Immune‐enhancing supplements (oral or enteral) showed no clear difference in infectious complications recorded up to 30 days postdischarge compared with usual care or control (low certainty).
Oral nutritional supplements showed no clear difference in non‐infectious complications recorded up to 30 days postdischarge compared with usual care or control (low certainty).
It is very uncertain whether oral nutritional supplements changes infectious complications recorded up to 30 days postdischarge compared with usual care or control (very low certainty).
It is very uncertain whether preoperative parenteral nutrition changes infectious complications compared with usual care or control (very low certainty).
The review found no eligible studies for this question.
It is very uncertain whether preoperative enteral nutrition (standard formula) changes infectious complications compared with usual care or control (very low certainty).