Table 2

Characteristics of included studies.

Study	Study Type and Data Source	Country	Mean Age, y		n		Follow-up, mo	Diagnosis	Surgery Type
Study	Study Type and Data Source	Country	MIS	Open	MIS	Open	Follow-up, mo	Diagnosis	Surgery Type
Slotman 199812	RC cost analysis from hospital charges database	USA	37	42	40	31	34	DDD and LS	Open vs lap discectomy
VD Akker 201113	CEA using Euro QOL 5D from randomized controlled trial	Holland	NR	NR	155	159	12	DDD and LS	Open vs MIS discectomy
Lucio 201214	PNRC cost analysis from hospital charges database	USA	64	58	109	101	60	DDD, LS, and DLS	1- and 2-level MIS-TLIF vs open TLIF
Parker 201215	PNRC CEA using Euro QOL 5D	USA	50.8	49.75	9	8	24	DDD, LS, and DLS	Single-level MIS-TLIF vs open TLIF
Wang 201216	RC cost analysis	USA	52	56	52	22	NR	DDD, LS, and DLS	1- and 2-level MIS vs open posterior lumbar interbody fusion
Pelton 201217	PNRC cost analysis	USA	51.6	49.8	33	33	24	DDD, LS, and DLS	Open vs MIS single-level TLIF
Udeh 201218	Cost-utility analysis using Euro QOL 5D and decision model analysis	USA	NR	NR	301	292	24	DDD and LS	Open vs MIS laminectomy
Cahill 201319	RC cost analysis from hospital charges database	USA	45	50	48	33	36	DDD and LS	Open vs MIS discectomy
Parker 201320	RC CEA	USA	59.5	54	27	27	24	DDD and LS	Open vs MIS laminectomy
Singh 201321	PNRC cost analysis from hospital costs database	USA	51.6	49.8	33	33	NR	DDD, LS, and DLS	Open vs MIS single-level TLIF
Parker 201422	CEA using Euro QOL 5D from PNRC	USA	53.5	52.6	50	50	24	DDD, LS, and DLS	Single-level open vs MIS-TLIF
Sulaiman 201423	RC cost analysis from hospital charges database	USA	61	56	57	11	12	DDD, LS, and DLS	Open vs MIS-TLIF
Maillard 201424	RC cost-minimization study (cost-effectiveness measured by hospital cost vs reimbursement)	France	50	59	24	22	12	DDD, LS, and DLS	1- and 2-level open vs MIS-TLIF
R’saud 201525	RC CEA using Euro QOL 5D	Canada	57	55	37	41	24	DDD, LS, and DLS	1- and 2-level open vs MIS-TLIF
Vertuani 201526	CEA using Euro QOL 5D and decision model analysis	UK/Italy	NR	NR	NR	NR	NR	DDD, LS, and DLS	1- and 2-level open vs MIS-TLIF
G’hoke 201627	RC CEA using Euro QOL 5D	USA	57	58	29	45	24	DDD and LS	1-level open vs MIS-TLIF
Djurasovic 201928	PNRC using EQ-5D and SF-6D	USA	57.6	57.0	33	33	12	DLS and DDD	1- and 2-level open vs MIS-TLIF

Abbreviations: CEA, cost-effectiveness analysis; DDD, degenerative disc disease; DLS, degenerative lumbar spondylolisthesis; LS, Lumbar stenosis; MIS, minimally invasive surgery; NR, not recorded/reported; PNRC, prospective nonrandomized cohort study; RC, retrospective cohort study; TLIF, transforaminal lumbar interbody fusion.