# Table 4 Result of individual variable meta-regression models for each stratified meta-analysis

Stratified meta-analyses
Study Characteristic HIV prevalence HCV prevalence HIV-HCV co-infection prevalence
Pooled estimate Meta-regression Pooled estimate Meta-regression Pooled estimate Meta-regression
% (95% CI), n , p-value) % (95% CI), n , p-value) % (95% CI), n , p-value)
Language of article:
Chinese 6.0 (4.7-7.6), n = 70 0.060 60.1 (52.6-67.2), n = 69 0.018 4.2 (2.5-6.8), n = 18 0.402
English 8.4 (2.7-23.0), n = 2 p = 0.956 57.9 (35.9-77.1), n = 2 p = 0.964 13.5 (10.9-16.6), n = 1 p = 0.823
Sample size:
<500 4.8 (3.4-6.7), n = 50 0.178 59.8 (54.6-64.9), n = 53 -0.189 2.2 (1.2-4.1), n = 11 1.367
≥500 8.2 (5.6-11.8), n = 22 p = 0.561 60.3 (42.3-75.8), n = 18 p = 0.191 9.8 (5.7-16.2), n = 8 p= 0.029
Study locations*:
HTA 17.5 (14.0-21.6), n = 27 -1.811 70.2 (62.6-76.8), n = 21 -0.335 8.0 (4.8-12.9), n = 10 -0.831
LTA 2.4 (1.6-3.5), n = 45 p< 0.001 55.5 (46.4-64.2), n = 50 p= 0.017 2.5 (1.4-4.4), n = 9 p = 0.139
Sampling method:
Cross-sectional 5.7 (4.3-7.4), n = 580 0.148 62.4 (54.2-69.9), n = 60 -0.275 4.6 (2.9-7.2), n = 19 -
Others 8.3 (5.1-13.2), n = 14 p = 0.686 46.2 (36.3-56.5), n = 11 p = 0.112 - -
Time period:
2004–2006 8.0 (5.2-12.2), n = 16 -0.268 56.7 (47.0-65.8), n = 13 0.026 4.5 (0.3-40.4), n = 2 0.353
2007–2010 5.5 (4.1-7.3), n = 56 p = 0.458 60.9 (52.1-69.0), n = 58 p = 0.879 4.4 (2.7-7.2), n = 17 p = 0.803
1. Table showing the pool estimate (%), 95% confidence interval (CI), number of studies (n), meta-regression coefficient (β) and significance of β (p-value). p-values in bold print represent significant associations (p < 0.10).
2. * Study locations were categorized into two regions. HTA (high HIV transmission areas among DUs): Yunnan, Guizhou, Sichuan, Guangxi and Xinjiang; LTA (low HIV transmission areas among DUs): all provinces except above in Chinese mainland. 