Table 1. Characteristics of included studies.

Source	Study Type	Surgery	Frailty Instrument	Control (n)	Intervention (n)	Mean age	Intervention
Bakker et al, 201427	CBA	Mixed	Geriatric examination	191	195	77	Enhanced care protocol
Binder et al, 200433	RCT	Hip Fracture	mPPT score and ADLs	44	46	80	Post-operative exercise
Chen et al, 201426	CBA	General	Fried’s frailty phenotype	52	52	73	Enhanced care protocol
Gorelik et al, 201524	Unclear	General	Geriatric examination	35	36	82	Enhanced care protocol
Gregersen et al, 201535−37	RCT	Hip Fracture	Comprehensive Geriatric Assessment	140	144	86	Blood transfusion trigger
Hempenius et al, 201329	RCT	Solid tumor	Groningen Frailty Indicator	149	148	77	Enhanced care protocol
Hoogeboom et al, 201030	RCT	Hip replacement	Clinical Frailty Scale	11	10	77	Pre-operative exercise
Indrakusuma et al, 201425	CBA	General	ISAR	50	50	81	Enhanced care protocol
Molino-Lova et al, 201134	RCT	Cardiac	SPPB score	48	51	75	Post-operative exercise
Oosting et al, 201231	RCT	Hip replacement	ISAR	15	15	77	Pre-operative exercise
Opasich et al, 201032	CBA	Cardiac	BPOMA	74	150	75	Post-operative exercise

BPOMA: Balance Performance Oriented Mobility Assessment; CBA: controlled before after; ISAR: Identification of Seniors At Risk; mPPT: modified version of the Physical Performance Test; RCT: randomized controlled study; SPPB: Short Physical Performance Battery score