Using simple linear regression with each study weighted by their sample size, HIV+ individuals in the US had a higher mean age (B = 10.0, P = 0.001), were more likely non-white (B = 27.3, P = 0.005), had viral loads < 1000 copies (B = 5.05, P = 0.001), hepatitis C (B = 24.33, P = 0.01) or higher CD4 counts (B = 48.1, P = 0.01) than their European counterparts. Here, CD4 is linked to hepatitis C virus infection.