Table 2.

Clinical and inflammatory characteristics of comorbid pain: a multivariable logistic regression model (n=235)

Covariates	Odds ratio	95% Confidence interval	P-value
Age (years)	1.03	0.99, 1.06	0.08
Sex	1.08	0.56, 2.07	0.82
Response to MMT (% positive opioid urine tests)	1.02	1.00, 1.03	0.01
Infectious disease status	1.40	0.65, 3.00	0.38
Methadone dose (mg/d)	1.00	0.99, 1.01	0.94
Presence of inflammatory medications	1.26	0.41, 3.92	0.69
TNF-α	0.69	0.37, 1.30	0.25
IFN-γ	2.02	1.17, 3.50	0.01
IL-6	1.18	0.60, 2.32	0.63
IL-1ra	0.84	0.51, 1.37	0.49
CCL2	1.60	0.88, 2.88	0.12
IL-8	0.73	0.43, 1.21	0.22
IL-10	1.01	0.69, 1.48	0.97

Notes: Sex is interpreted as female, in reference to males. Infectious disease status was a binary measure of the presence of HIV and/or hepatitis. All cytokine measurements have been log-transformed, and the original measurements were in picograms per milliliter.

Abbreviations: MMT, methadone maintenance treatment; IL, interleukin; IL-1ra, interleukin 1 receptor antagonist; TNF, tumor necrosis factor; CCL2, chemokine (C–C motif) ligand 2; HIV, human immunodeficiency virus; IFN, interferon.