Patients infected outside of Sweden - sensitivity analysis of year of HIV-1 diagnosis and the trends in subtype pattern during 1983–2012, using subtype B (HIV-1B) as reference.

<p>An univariate multinomial logistic regression model <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0099390#pone.0099390-Lee1" target="_blank">[17]</a> was used. The outcome (the HIV-1 subtypes) was grouped into HIV-1B (reference group), HIV-1C, recombinants, and other pure subtypes. Relative risk ratio and 95% confidence intervals were determined. RRR represents relative risk ratio.