Table 1.

Baseline factors predicting global outcome (0 = poor, 1 = good) at 12 months’ follow-up

Variable	12 Months postop
	Individual indicators			Multiple regression
	OR	95 % CI	p value	OR	95 % CI	p value
Age (years)	1.000	0.965; 1.035	0.979
Gender (0 = F, 1 = M)	1.127	0.518; 2.450	0.763
Number of levels to be operated (1–5)	1.043	0.681; 1.598	0.846
Currently employed (0 = N, 1 = Y part or full time)	2.073	0.864; 4.976	0.103
Claim for disability (0 = N, 1 = Y considering, applied or received)	0.333	0.126; 0.878	0.026
Time in treatment for back problem (months, log transformed)	0.905	0.704; 1.162	0.434
Previous spine surgery (0 = N, 1 = Y)	0.745	0.264; 2.100	0.577
LBP frequency in the past 6 months	0.341	0.146; 0.792	0.012	0.340	0.141; 0.818	0.016
Use of painkillers in the previous 6 months	0.811	0.579; 1.135	0.222
LBP intensity, in the last week	0.818	0.704; 0.950	0.009
Leg pain intensity, in the last week	0.850	0.716; 1.009	0.063
Average of all pain scales	0.728	0.585; 0.906	0.005
Painkillers today	0.462	0.212; 1.003	0.051
Other joint problems (0 = N, 1 = Y)	0.448	0.192; 1.048	0.064
Systemic diseases/co-morbidity	0.974	0.446; 2.127	0.947
General medication for systemic diseases	1.028	0.450; 2.348	0.948
Sleep disturbance	0.884	0.520; 1.505	0.651
General health	1.100	0.920; 1.314	0.295
Smoker (0 = N, 1 = Y)	0.403	0.162; 1.006	0.051
Psychological distress, sum of MSPQ + ZUNG	0.970	0.938; 1.003	0.078
Roland Morris Disability (range 0–24)	0.923	0.851; 1.001	0.054
FABQ-physical activity (range 0–28)	0.879	0.815; 0.949	0.001	0.877	0.809; 0.949	0.001
Pain catastrophising (range 0–36)	0.949	0.901; 0.999	0.046

LBP low back pain, MSPQ Modified Somatic Perception Questionnaire (enquires about the frequency of somatic symptoms experienced in the last week), ZUNG ZUNG self-rated depression, FABQ-physical activity Fear-Avoidance Beliefs about physical activity

p values marked in bold are p < 0.10 for the individual indicators (selected for multivariable model) and p < 0.05 for the multivariable model