Is the clinical course of HIV infection changing? Exclusion of people not followed up for 12 months may have biased results.
Law
M G
MG
Kaldor
J M
JM
D015982:Bias; D018791:CD4 Lymphocyte Count; D018450:Disease Progression; D005500:Follow-Up Studies; D015658:HIV Infections / Q000401:mortality*; D006801:Humans