Table 1.

Model Parameters and Assumptions

Variable	Base Case		Range	Source
Baseline characteristics
Age structure of infected population presenting to care				Badri[8], Dorrington[28], IDB[29]
15-25 years old	34%
25-35 years old	39%
35-50 years old	27%
CD4 count at presentation, cells/μl (mean ± SD)	144 ± 121			ART-LINC[9]
Viral load at presentation, log copies/ml (mean ± SD)	5.0 ± 0.8			Badri[6]
Disease Progression Variables
Decline in CD4 (cells/μl/mo), viral load 10³-10⁶				Holmes[21], Mellors[30], Rodriguez[31], PLATO[32]
Baseline CD4 >500 cells/μl	3.9-5.9		± 50%
Baseline CD4 351-500 cells/μl	2.6-3.8		± 50%
Baseline CD4 201-350 cells/μl	1.7-2.6		± 50%
Baseline CD4 <200 cells/μl	1.3-2.0		± 50%
Monthly probability of developing severe opportunistic diseases (%), by CD4	<50 cells/μl	51-200 cells/μl	201-350 cells/μl	>350 cells/μl	Holmes[21]
Oral candidiasis	3.50%	2.04%	1.26%	0.57%
Chronic diarrhea	2.00%	0.49%	0.18%	0.00%
Esophageal candidiasis	1.46%	0.34%	0.09%	0.06%
Wasting syndrome	1.29%	0.23%	0.02%	0.00%
Severe bacterial	1.15%	0.04%	0.03%	0.00%
Pulmonary TB	1.15%	0.71%	0.47%	0.11%
Extrapulmonary TB	0.98%	0.47%	0.18%	0.05%
PCP	0.67%	0.05%	0.02%	0.00%
CMV	0.52%	0.07%	0.02%	0.00%
Cryptococcal meningitis	0.52%	0.05%	0.00%	0.00%
Risk of HIV death by CD4 cell count				Badri[7], ART-LINC[9]
CD4 <50 cells/μl	2.1%/mo		± 10%
CD4 51-200 cells/μl	1.7%/mo		± 10%
CD4 201-350 cells/μl	1.1%/mo		± 10%
CD4 >350 cells/μl	0.8%/mo		± 10%
Cumulative risks of toxicity and failure	Year 1		Year 3	Range	Source
tenofovir + lamivudine + efavirenz
Virologic failure	12%		24%	± 4%	Gallant, Arribas[10, 33]
Lipoatrophy	6%		17%	± 3%	Haubrich[11]
Renal failure	1%		1%	± 1%	Gallant[11]
Myocardial infarction	0.1%		0.1%	± 0.1%	Gallant[12, 33, 34]
tenofovir + lamivudine + nevirapine	Year 1		Year 3	Range	Source
Virologic failure	18%		31%	± 6%	Gallant, Nachega, Smith[15, 33, 35]
Lipoatrophy	6%		17%	± 3%	Haubrich[11]
Renal failure	1%		1%	± 1%	Gallant[11]
Hepatotoxicity	6.3%		6.3%	± 5%	Amoroso[14]
zidovudine + lamivudine + efavirenz	Year 1		Year 3	Range	Source
Virologic failure	17%		31%	± 7%	Gallant[33], Arribas[10]
Lipoatrophy	23%		54%	± 15%	Arribas, Haubrich[10, 11]
Anemia	6%		6%	± 3%	Gallant[33]
Myocardial infarction	0.2%		0.2%	± 0.2%	Gallant[12, 33, 34]
zidovudine + lamivudine + nevirapine	Year 1		Year 3	Range	Source
Virologic failure	25%		46%	± 12%	Gallant, Arriba, Nachega, Smith [10, 15, 33, 35]
Lipoatrophy	23%		54%	± 15%	Arribas, Haubrich[10, 11]
Anemia	6%		6%	± 3%	Gallant[33]
Myocardial infarction	0.1%		0.1%	± 0.1%	Gallant[12, 33, 34]
Hepatotoxicity	6.3%		6.3%	± 5%	Amoroso[14]
stavudine + lamivudine + nevirapine	Year 1		Year 3	Range	Source
Virologic failure	18%		31%	± 6%	Gallant, Nachega, Smith[15, 33, 35]
Lipoatrophy	30%		66%	± 20%	Haubrich[11]
Neuropathy	25%		25%	± 10%	Gallant[11]
Myocardial infarction	0.3%		0.3%	± 0.3%	Gallant[12, 33, 34]
Hepatotoxicity	6.3%		6.3%	± 5%	Amoroso[14]
Lactic acidosis	0.5%		0.5%	± 0.2%	John, Boubaker [36, 37]
Quality of life weights and duration of toxicities
HIV without HAART	0.84			0.84-1	Cleary[38]
HIV with HAART	0.91			0.91-1	Cleary[38]
Lipoatrophy	0.87	Irreversible		0.8-0.95	Rosen[23, 39]
Anemia	0.58	4 mo		0.5-0.66	Kimel[40]
Renal failure	0.7	4 mo		0.6-0.8	Rosen[23, 39]
Neuropathy	0.87	Irreversible after 1 year		0.8-0.95	Gallant[12]
Lactic acidosis	0.5	3 mo		0.4-0.6	Rosen[23, 39]
MI	0.6	2 mo		0.4-0.8	Assumption
Hepatotoxicity	0.7	2 mo		0.5-0.9	Assumption
Utilization and cost variables
Annual number of inpatient days without a severe opportunistic disease				Badri et al[6, 41]
CD4>350 (on/off HAART)	0.14 / 1.9		± 50%
CD4 201-350 (on/off HAART)	0.39 / 3		± 50%
CD4<=200 (on/off HAART)	0.26 / 7.7		± 50%
Annual number of inpatient days with a severe opportunistic disease				Badri et al[6, 41]
CD4>350 (on/off HAART)	0.37 / 5.7		± 50%
CD4 201-350 (on/off HAART)	0.52 / 10.8		± 50%
CD4<=200 (on/off HAART)	1.8 / 17.7		± 50%
Annual number of outpatient visits				Badri et al[6, 41]
CD4>350 (on/off HAART)	4.3 / 4.1		± 50%
CD4 201-350 (on/off HAART)	3.9 / 5.0		± 50%
CD4<=200 (on/off HAART)	4.7 / 6.6		± 50%
Monitoring Costs (2009 USD)
Inpatient Day	$182		± 50%	Badri; Cleary[6, 38]
Outpatient visit	$26		± 50%	Badri; Cleary[6, 38]
Cost per CD4 test	$15		± 50%	Badri, Zijeneh[6, 42]
HAART Costs (2009 USD)				WHO[43]
tenofovir + lamivudine + efavirenz	$675		$100-675
tenofovir + lamivudine + nevirapine	$538		$100-538
zidovudine + lamivudine + efavirenz	$384		$100-384
zidovudine + lamivudine + nevirapine	$247		$100-247
stavudine + lamivudine + nevirapine	$121		$100-121
Second line HAART	$769		$100-769
Toxicity costs
Lipoatrophy	$121		$60-242	Rosen[23]
Anemia	$136		$68-272	Cantor[44]
Renal failure	$213		$106-8,477	Rosen[23]
Neuropathy	$130		$65-260	Rosen[23]
Lactic acidosis	$192		$96-7,999	Rosen[23]
MI	$300		$150-600	Assumption
Hepatotoxicity	$300		$150-600	Assumption