Table 2.

Relative risk of progression to an AIDS-defining event or AIDS related death per 0.3, 0.5, and 1.0 log₁₀ increment of plasma HIV RNA concentration.

					Risk ratio per log₁₀ Δ HIV RNA
Reference	No. of Events	CD4⁺ cells/μl^a	Primary Outcome	Viral assay	0.3	0.5	1.0
Welles et al. [35]	187	139	AIDS, Death	bDNA	1.36 (1.12, 1.66)	1.67 (1.20, 2.32)	2.79 (1.44, 5.38)
Coombs et al. [36]	97	85	AIDS, Death	bDNA	1.26 (1.03, 1.54)	1.47 (1.05, 2.05)	2.26 (1.10, 5.13)
Sterling et al. [37]	202	659	AIDS, Death	RT-PCR	1.14 (0.98, 1.32)	1.24 (0.97, 1.59)	1.55 (0.95, 2.52)
Phillips et al. [38]	219	NP	AIDS	Combination^b	1.24 (1.17, 1.31)	1.42 (1.30, 1.57)	2.03 (1.68, 2.46)
Lavreys et al. [39]	40	498	Death	Gen-Probe	1.28 (1.10, 1.47)	1.51 (1.17, 1.89)	2.28 (1.36, 3.59)

Weighted mean					1.25 (1.08, 1.44)	1.44 (1.14, 1.84)	2.13 (1.33, 3.62)

bDNA, branched DNA signal-amplification assay (Chiron, Emeryville, CA, USA.); RT-PCR, reverse transcriptase – polymerase chain reaction (Amplicor HIV monitor test, Roche Diagnostic Systems, Inc., Branchburg, NJ, USA.); NASBA, nucleic acid sequence based amplification technique (Organon Teknika, Boxtel, Holland); Gen-Probe (Gen-Probe HIV-1 viral load assay; Gen-Probe, Inc., San Diego, CA, USA); NP, not provided.

Values reflect median CD4⁺ T lymphocyte count/μl among infected persons at baseline.

55% of viral loads was measured by RT-PCR, 17.9% by an unknown method, 14.6% by NASBA, 7.8% by bDNA, and 4.8% by another method.