Table 3.

Results From Univariable Meta-regression on Log Odds of Sustained Virologic Response^a,b

Variable	No. ofStudies	CoefficientEstimate	95% CI	P Valuec	PearsonCorrelationCoefficient	HeterogeneityParameter (I2)d	PValue
Treatment of addiction during HCV therapy	26	−0.0426	−.9784, .8932	.9289	−0.0468	0.2014 (0.7020)	<.0001
Genotype 1 or 4	26	−1.7062	−2.7413, −.6712	.0012*	−0.7058	0.1349 (0.7031)	<.0001
Human immunodeficiency virus	22	−1.5767	−2.8753, −.2781	.0173*	−0.5921	0.1418 (0.6794)	<.0001
Location in United States	32	−0.5847	−1.1294, −.0401	.0354*	−0.4929	0.2077 (0.7777)	<.0001
Support services offered	31	−0.0245	−.4556, .4067	.9114	−0.0967	0.2343 (0.7909)	<.0001
Multidisciplinary team involved	32	0.0626	−.3506, .4759	.7665	0.0830	0.2265 (0.7800)	<.0001
Methadone maintenance during HCV treatment	20	−0.4157	−1.1916, .3602	.2937	−0.4871	0.163 (0.6029)	.0002
Study design (randomized or matched control vs other)	32	−0.1484	−.7701, .4733	.6399	0.0747	0.2133 (0.7847)	<.0001
Age	20	−0.0088	−.0486, .0311	.6656	−0.3288	0.1191 (0.5187)	.0025
Male	22	0.1513	−1.3726, 1.6752	.8457	0.0123	0.2541 (0.7993)	<.0001
Caucasians from US studies	6	0.0424	−1.1812, 1.2659	.9459	0.0987	0.1405	.1386
African American from US studies	4	−4.8407	−11.1615, 1.4801	.1333	−0.8544	0.039	.2711
Psychiatric comorbidities	14	−0.151	−1.1111, .8092	.758	−0.3007	0.1704 (0.7117)	<.0001
Substitution therapy at baselinee	24	−0.246	−1.2266, .7345	.6229	−0.1652	0.2163 (0.7224)	<.0001
Drug use during HCV treatment	15	0.346	−.1833, .8754	.2001	0.3777	0.0462	.0887
Biopsy performed	14	−0.2575	−.9557, .4407	.4697	−0.1952	0.071 (0.4498)	.0228

Abbreviations: CI, confidence interval; HCV, hepatitis C virus.

^a Results listed in order as presented in the text.

^b Results from the univariable meta-regression expressed as , where θ_i is the log odds for achieving a sustained virologic response from study i, β₀ is intercept, b_i is random effect for study i, x_i is the value of the covariate from study i, and ε_i is the within study error. The covariates are expressed either as proportions (treatment of addiction during HCV therapy, substitution therapy at baseline, drug use during HCV treatment, genotype 1 or 4, human immunodeficiency virus infection, male, African American from US studies, Caucasians from US studies, psychiatric comorbidities, biopsy performed, methadone maintenance during HCV treatment), as categorical variables (study design, location in United States, multidisciplinary team involved, support services offered) or as continuous variables (median/mean age).

^c Significant P values are indicated with an asterisk.

^d I² added if heterogeneity is present.

^e Substitution therapy included patients on either methadone or buprenorphine.