Table 5. Subgroup analyses.

	Number of studies	OR (95% CI)	p-value
Mortality
Clinical settings
Community	7	3.39 (2.65–4.33)	0.63
Hospital	3	4.73 (2.46–9.12)
Nursing home	2	3.32 (1.84–5.98)
Age
≤ 79 years	6	3.09 (2.49–3.84)	0.02
> 79 years	6	4.42 (3.60–5.42)
Length of follow-up
≤ 36 months	6	3.31 (2.17–5.07)	0.23
> 36 months	6	3.72 (3.02–4.60)
NOS score
≤ 7 points	5	4.06 (3.06–5.38)	0.16
> 7 points	7	3.05 (2.32–4.01)
Tool used for muscle mass measure
BIA	4	4.84 (3.47–6.74)	0.06
DXA	4	3.58 (2.73–4.63)
Anthropometric measures	4	2.67 (1.84–3.87)
Functional decline
Age
≤ 75 years	3	3.79 (1.36 -10-6)	0.52
> 75 years	3	2.52 (1.26–5.03)
Length of follow-up
≤ 51.5 months	3	3.31 (0.87–12.55)	0.79
> 51.5 months	3	2.75 (1.75–4.31)
Tool used for muscle mass measure
BIA	3	4.24 (2.87–6.27)	0.29
DXA	3	2.18 (1.74–2.74)

Nb. Subgroup analyses for clinical settings and NOS score could not be performed for functional decline given the limited number of studies for these groups (one unique study with a NOS score ≤ 7 and one unique study performed with hospitalized subjects).