Adjusting for use of HAART, history of AIDS, years since entering the DHCS, CCI score, age, and current CD4+ cell count, the relative mortality during the first 90 days after an initial hospitalization for pneumonia, compared to those with no previous hospitalization for this indication, was 5.38 (adjusted mortality rate ratio [MRRadj], 95% CI: 4.27–6.78). The gene discussed is CD4; the disease is susceptibility to pneumonia measurement.