Table 1.

Characteristics of 67 855 lumbar spine operations in 57 081 patients in Norway, 1999–2013

	No. of operations (%)	Length of stay, days, median (range, IQR)
Age (years)
18-39	16396 (24.2)	4.2 (724, 4.4)
40-59	28237 (41.7)	6.3 (618, 4.7)
60-75	16160 (23.9)	5.9 (250, 5.8)
> 75	6910 (10.2)	7.2 (226, 6.7)
Missing	152
Gender
Male	34902 (51.4)	4.7 (239, 4.4)
Female	32801 (48.3)	6.0 (724, 5.8)
Missing	152
Year of operation
1999	3460 (5.1)	7.1 (149.9, 6.0)
2000	3996 (5.9)	7.0 (420, 6.0)
2001	4200 (6.2)	7.0 (138, 6.0)
2002	3865 (5.7)	6.2 (202, 6.0)
2003	4557 (6.7)	6.1 (238, 5.4)
2004	4396 (6.5)	6.1 (250, 5.8)
2005	4572 (6.7)	6.0 (724, 5.3)
2006	4422 (6.5)	5.8 (138, 5.5)
2007	4255 (6.3)	5.1 (618, 5.0)
2008	4164 (6.1)	4.9 (179, 4.3)
2009	4449 (6.6)	4.2 (142, 4.9)
2010	5130 (7.6)	4.1 (183, 4.8)
2011	5241 (7.7)	4.0 (210, 4.2)
2012	5597 (8.2)	4.1 (165, 4.2)
2013	5551 (8.2)	3.8 (219, 4.1)
Missing	0	0
Type of surgery
Simple	56764 (83.7)	4.3 (724, 4.3)
Complex	11091 (16.3)	8.2 (420, 5.7)
No. of operations
1	57029 (84.0)	5.1 (724, 5.0)
2	8623 (12.7)	5.2 (618, 5.1)
3	1602 (2.4)	6.2 (205, 6.0)
≥ 4	467 (0.7)	6.9 (115, 4.4)
Missing	134	134