Table 3.

Univariate Analysis of Baseline

Predictors of Pain Improvement11	Column1	Column2	Column3
Variable (units)	R2	F	Significance
Age (years)	0.005	0.26	0.61
Gender (female, male)	0.001	0.06	0.82
Work status (yes, no, retired)	0.014	0.23	0.87
Marital status (yes, no)	0.001	0.07	0.8
Taking opioids at baseline (yes, no)	0.09	4.7	0.04*
Baseline pain (0-10)	0	0.01	0.91
Pain duration (years)	0.01	0.57	0.46
Radicular pain (yes, no)1	0.009	0.24	0.79
Neuropathic pain (yes, no)2	0.04	0.94	0.4
Pain interference (0-10)3	0.12	7.2	.01*
Function (0-100%)4	0.003	0.16	0.67
Opioid misuse risk score (0-96)5	0.17	9.9	.003*
Substance abuse history (yes, no)	0.015	0.78	0.38
Pain catastrophizing (0-52)7	0.05	0.12	0.74
Neuroticism (T score)11	0.02	1.2	0.28

¹Intermittent only per history (not constant or daily)

²Composite measure of burning, shooting, and sensitivity to touch symptoms, assessed with the Neuropathic Pain Questionnaire

³Average of the pain interfence items on the Brief Pain Inventory

⁴Oswestry Disability Index

⁵Screener for Opioid Assessment in Patients with Pain, Revised (SOAPP-R). Score >14 predicts a high likihood of future opioid misuse

⁶ Results of the MINI neuropsychiatric structured interview

⁷Pain Catastrophizing Scale

⁸Neuroticism Subscale of the NEO Personality Inventory ‘T’ scores above 60= >85th percentile for neuroticism

⁹ Depression subscale of the HADS

¹⁰ Anxiety subscale of the HADS

¹¹Average weekly percent improvement in pain during the opioid continuation period

^*Continued to ANCOVA stage of testing