Table 3.

Construct Validity Across Categories of Baseline HIV Viral Load and CD4

HIV RNA	Obs	Mean SDS	Std. Dev.	Min	Max	p-value∫
0–499	1,944 (35.2%)	25.9	19.4	0	100	< 0.001
500–4,999	620 (11.2%)	30.2	21.3	0	87.5
5,000–49,999	681 (12.3%)	30.9	22.0	0	100
50,000–499,999	421 (7.6%)	34.3	22.4	0	100
500,001+	42 (0.8%)	41.3	23.5	2.5	87.5
Missing	1,813 (32.8%)	-	-	-	-

CD4 cells/μl	Obs	Mean SDS	Std. Dev.	Min	Max	p-value∫
<100	263 (4.8%)	41.6	22.7	0	95	< 0.001
100–199	368 (6.7%)	34.7	21.6	0	87.5
200–299	583 (10.6%)	31.0	20.8	0	93.75
300–500	1,334 (24.2%)	29.1	20.8	0	100
>=501+	1,675 (30.3%)	25.1	19.5	0	100
Missing	1,298 (23.5%)

^∫A test for trend across the ordered groups.