Economic and health-related quality-of-life (HRQoL) comparison of lopinavir/ritonavir (LPV/r) and atazanavir plus ritonavir (ATV+RTV) based regimens for antiretroviral therapy (ART)-naïve and -experienced United Kingdom patients in 2011

Figures & data

     Figure 1.  Markov model structure with health states defined by CD4+ T-cell count, viral load categories, AIDS event, or death7.

Table 1.  Model cohorts at 48 weeks per respective literature results.

Characteristic	LPV/r cohort	ATV+RTV cohort
CASTLE study of ART-naïve patients
CD4+ T-cell^a increase at 48 weeks	219	203
VL response rate (% with < 400 RNA copies/mL) at 48 weeks	82%	86%
VL response rate (% with < 50 RNA copies/mL) at 48 weeks	76%	78%
10-year risk of a CHD event at baseline	4.6%	4.6%
10-year risk of a CHD event at 48 weeks	5.6%	4.7%
Percent treated on lipid-lowering drugs after 48 weeks	18%	7%
BMS-045 study of ART-experienced patients
CD4+ T-cell^a increase at 48 weeks	121	110
VL response rate (% with < 400 RNA copies/mL) at 48 weeks	58%	56%
VL response rate (% with < 50 RNA copies/mL) at 48 weeks	46%	38%
10-year risk of a CHD event at baseline	4.6%	4.6%
10-year risk of a CHD event at 48 weeks	5%	4.2%
Percent treated on lipid-lowering drugs after 48 weeks	19%	8%

^aNumber of CD4+ T-cells cells/µL

LPV/r, lopinavir/ritonavir; ATV+RTV, atazanavir plus ritonavir; ART, antiretroviral therapy; VL, viral load; RNA, ribonucleic acid; CHD, coronary heart disease.

Table 2.  Health states populating model with their associated QALY weights and corresponding AIDS event costs for the United Kingdom (UK; 2011 totals per quarter).

Health state	CD4+ T-cell range^a	VL range^b	QALY weight applied*	HIV treatment costs applied^c
1	>500	<400	0.954	£1577
2	>500	≥400	0.938	£2011
3	351–500	<400	0.934	£1662
4	351–500	≥400	0.931	£2119
5	201–350	<400	0.929	£1662
6	201–350	400–19,999	0.931	£1936
7	201–350	≥20,000	0.933	£2486
8	50–200	<400	0.863	£5607
9	50–200	400–19,999	0.865	£6123
10	50–200	20,000–100,000	0.826	£10,743
11	50–200	>100,000	0.876	£15,878
12	<50	Any level	0.781	£10,969

^aNumber of CD4+ T-cells per microliter; ^bRNA copies/mL; ^ccosts exclude ART drugs.

*The utility weight in this table is adjusted by a decrement of 0.400 for patients with CHD. Thus, a patient in HS 12 with CHD would have a utility weight of 0.381.

QALY, quality-adjusted life-year; AIDS, acquired immune deficiency syndrome; HIV, human immunodeficiency virus.

Table 3.  Model drug and treatment switching cost in 2011.

Cost factor description	Costs	Source
ATV 300 mg/day	£10.11	MIMS 2011
RTV boost 100 mg/day	£0.65	MIMS 2011
NRTI backbone^a per day	£10.03	MIMS 2011
LPV/r 800/200 mg/day	£9.51	MIMS 2011
Pravastatin 40 mg/day	£0.18	MIMS 2011
Cost of switching ART regimen, including genotypic resistance testing	£804*
Myocardial infarction (per event)	£3400*	Castiel et al.13
Myocardial infarction (per event)	£3841**	2011 NHS tariff

^aThe model assumes that patients will receive 200 mg emtricitabine and 300 mg tenofovir once daily as a combination tablet.

*Inflated to 2011 prices.

**This value was used in the sensitivity analysis.

NRTI, nucleoside reverse transcriptase inhibitor; MIMS, Monthly Index of Medical Specialties; NHS, National Health Services.

Table 4.  ATV+RTV regimen incremental cost-effectiveness ratios and LPV/r regimen savings estimates for the UK, 2011.

Population	ATV+RTV cost/QALY	LPV/r 5-year savings	LPV/r 10-year savings	LPV/r lifetime savings	LPV/r discounted lifetime savings
ART-naïve	£149,270	£2133	£3409	£4070	£3558
ART-experienced	LPV/r is modestly dominant	£5538	£7623	£1604	£1445

Table 5.  Sensitivity analysis assumption changes and resulting ICERs.

Parameter varied	ART-naïve model ICER for ATV+RTV	ART-experienced model ICER
Baseline model	£149,270	LPV/r Dominant
Cost of CHD £3841	£149,230	LPV/r Dominant
Cost of CHD £8000	£144,661	LPV/r Dominant
Cost of lipid-lowering drug cost increased by 50%	£147,375	LPV/r Dominant
Cost of lipid-lowering drug cost decreased by 50%	£151,165	LPV/r Dominant
Daily cost of RTV £1.12	£192,999	LPV/r Dominant
Second and 3rd ARV regimen cost increased by 50%	£152,564	LPV/r Dominant
Second and 3rd ARV regimen cost decreased by 50%	£145,976	LPV/r Dominant
Very high CHD risk: All patients in model assumed to smoke and have elevated systolic BP controlled by medication to a mean of 140 mmHg	£53,906	LPV/r Dominant
Cost of AIDS events increased by 50%	£161,056	LPV/r Dominant
Cost of AIDS events decreased by 50%	£137,484	LPV/r Dominant

Viral Suppression, or Death by Health State for ARV-naïve Patients Over a Three Month Model Cycle.

	State 1	State 2	State 3	State 4	State 5	State 6	State 7	State 8	State 9	State 10	State 11	State 12	Died	Check
HS 1	0.8257	0.046	0.1009	0.0183	0	0.0092	0	0	0	0	0	0		1.0000000
HS2	0.6667	0.222	0	0.1111	0	0	0	0	0	0	0	0		1.0000000
HS3	0.3214	0.036	0.4954	0.0893	0.0536	0	0	0	0	0	0	0	0.00460	1.0000000
HS4	0.125	0	0.5	0.2454	0	0.125	0	0	0	0	0	0	0.00460	1.0000000
HS5	0	0	0.3571	0	0.5666	0.0476	0	0.0238	0	0	0	0	0.00490	1.0000000
HS6	0	0	0	0.1667	0.3333	0.162	0.1667	0.1667	0	0	0	0	0.00460	1.0000000
HS7	0	0	0	0	0	0	0.3288	0	0.3333	0	0.3333	0	0.00460	1.0000000
HS8	0	0	0	0	0.3871	0	0	0.5761	0	0.0323	0	0	0.00450	1.0000000
HS9	0	0	0	0	0	0.5	0	0	0	0.489	0	0	0.011240	1.0000000
HS 10	0	0	0	0	0	0	0	0	0.5	0.482	0	0	0.01786	1.0000000
HS 11	0	0	0	0	0		0	0	0	0.5	0.477	0	0.02308	1.0000000
HS12	0	0	0	0	0	0	0	0	0	0	0	0.95	0.05350	1.0000000
Died		1.000											1.000

Viral Suppression, or Death by Health State for ARV-Experienced Patients Over a Three Month Model Cycle.

	Undetect	Detectab	Undetect	Detectab	Undetect	<10,000	=>10,000	Undetect	<10,000	10–100,000	>100,000	Any VL
	>500	>500	351–500	351–500	201–350	201–350	201–350	50–200	50–200	50–200	50–200	<50
	State 1	State 2	State 3	State 4	State 5	State 6	State 7	State 8	State 9	State 10	State 11	State 12	Died
HS 1	0.599	0.324	0.035	0.038		0.004							0.00000
HS2		0.848		0.139		0.007	0.003			0.003			0.00000
HS3			0.454	0.337	0.076	0.076	0.016		0.033		0.0018	0.0017	0.00450
HS4				0.730	0.040	0.090	0.087		0.0057		0.0210	0.02173	0.00457
HS5					0.438	0.243	0.160	0.070	0.076	0.0081	0.0000	0.000	0.00490
HS6					0.009	0.772	0.110		0.049	0.042	0.0034	0.010	0.00460
HS 7							0.623		0.040	0.116	0.1310	0.085	0.00457
HS8		0.006		0.019		0.026	0.013	0.424	0.335	0.086	0.057	0.0295	0.00450
HS9								0.024	0.723	0.122	0.072	0.048	0.01124
HS 10									0.019	0.609	0.232	0.123	0.01786
HS 11									0.012	0.000	0.645	0.320	0.02308
HS 12									0.006	0.010	0.006	0.9245	0.05350

Simpson KN, Luo M, Chumney ECG, et al. Cost-effectiveness of lopinavir/ritonavir compared to atazanavir in antiretroviral-naïve patients: modeling the combined effects of HIV and heart disease. Clin Drug Investig 2007;27:67-74

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