Table 3.

Spearman rank-order correlations of outcome variables with patient satisfaction, EQ-5D, and K6 scores

Outcome score	FBSS			Patient satisfaction			EQ-5D			K6
	Correlation (Q)	P-value	n	Correlation (Q)	P-value	n	Correlation (Q)	P-value	n	Correlation (Q)	P-value	n
Low back pain	−0.407	<0.001	1739	0.537	<0.001	1739	0.420	<0.001	1739	−0.240	<0.001	1739
Dull ache	−0.351	<0.001	1317	0.464	<0.001	1317	0.410	<0.001	1317	−0.271	<0.001	1317
Numbness	−0.380	<0.001	1313	0.448	<0.001	1313	0.379	<0.001	1313	−0.223	<0.001	1313
Coldness	−0.304	<0.001	834	0.373	<0.001	834	0.313	<0.001	834	−0.200	<0.001	834
Paresthesia	−0.364	<0.001	691	0.427	<0.001	691	0.324	<0.001	691	−0.119	<0.001	691

Notes: Whole sample, N=1842. We excluded participants with outcome scores of 0. Connections between abnormal sensory symptoms (i.e., pain, dull ache, numbness, coldness, and paresthesia) and patient satisfaction, as well as EQ-5D and K6 scores were calculated using Spearman’s rank correlations.

Abbreviations: EQ-5D, EuroQol-5 dimensions; FBSS, failed back surgery syndrome; K6, Kessler psychological distress scale.