Table 2

Multivariate logistic regression model of factors associated with complications (including reoperation within 30 days) due to lumbar spine surgery in Norway from 1999 to 2013 (n=67 855)

Complications
(n=977)
ORLower 95% CIUpper 95% CI
Age (years)
 18-39250Ref
 40-594600.970.831.13
 60-751980.610.500.74
 > 75690.510.390.67
 Missing152
Gender
 Male510Ref
 Female4670.900.791.02
 Missing152
Length of stay (days)1.021.011.02
Type of surgery
 Simple659Ref
 Complex3182.342.042.69
Year of operation
 199924Ref
 2000290.980.571.71
 2001291.030.601.77
 2002331.310.772.22
 2003441.520.922.50
 2004411.460.882.43
 2005672.231.393.57
 2006602.251.403.63
 2007582.251.393.64
 2008562.291.423.71
 2009803.121.974.94
 2010893.031.934.78
 2011933.031.934.77
 20121404.312.794.67
 20131344.162.686.44
 Missing134