Table 1. Multiple ordinal logistic regression analysis on the effect of loneliness on pain intensity.

Variable		n	Pain Intensity Score
			Standardized Coefficient	Standard Error	Wald χ2	OR (95% CI)	P
Loneliness score		603	0.196	0.097	4.14	1.22 (1.01,1.47)	0.042
Gender	Male	412	0.045	0.188	0.057	1.05 (0.72,1.51)	0.812
	Female	191	1
Age(year)#	< 39	300	−0.071	0.192	0.137	0.93 (0.64,1.36)	0.712
	≥ 39	303	1
Length of Education#	< 9	140	−0.785	0.209	14.129	0.46 (0.30,0.69)	< 0.001
	≥ 9	463	1
Marital Status	Never-married	154	0.324	0.215	2.26	1.38 (0.91,2.11)	0.133
	Others*	154	0.154	0.235	0.431	1.17 (0.74,1.85)	0.512
	Married	295	1
Route of past heroin use	Injection	507	0.003	0.233	0.001	1.00 (0.64,1.58)	0.991
	Smoking	96	1
Duration of past heroin use (year)#	< 10	230	−0.237	0.181	1.721	0.79 (0.55,1.12)	0.190
	≥ 10	373	1
MMT dose (mg/d)#	< 70	273	−0.324	0.178	3.318	0.72 (0.51,1.03)	0.069
	≥ 70	330	1
MMT duration (months)#	< 24	240	0.578	0.185	9.811	1.78 (1.24,2.56)	0.002
	≥ 24	363	1
Depressive symptoms	Yes	204	0.939	0.212	19.659	2.56 (1.69,3.87)	< 0.001
	No	399	1
Anxiety symptoms	Yes	219	1.404	0.246	15.454	4.07 (2.51,6.59)	< 0.001
	No	384	1

#Continuous variables were dichotomized via the median split procedure.

*Others include remarried, divorced, separated, and widowed.