Cost–effectiveness of adding ezetimibe to atorvastatin vs switching to rosuvastatin therapy in Portugal

Figures & data

Table 1. Patient profiles.

	Atorvastatin (n = 37)*
Demographics
Age (mean, SD)	65.73 (10.22)
Male gender	18 (49%)
Hypertension
DBP (mean, SD)	77.35 (10.43)
SBP (mean, SD)	134.46 (18.43)
Medications for hypertension	21 (57%)
Cholesterol (mean, SD)
LDL-C	132.33 (27.30)
HDL-C	49.19 (8.69)
Triglycerides	168.65 (117.32)
Total cholesterol	219.32 (40.99)
CHD risk factors
History of CHD	18 (49%)
Diabetes	30 (81%)
Smoking (yes)	13 (35%)
Treatment regimen
Atorvastatin 10 mg	16 (43%)
Atorvastatin 20 mg	21 (57%)

*Values are presented as n (%) unless indicated otherwise.

DBP, diastolic blood pressure; SBP, systolic blood pressure. LDL-C, low-density lipoprotein cholesterol; HDL-C, high-density lipoprotein cholesterol; CHD, coronary heart disease.

Figure 1. Decision tree model structure.

Table 2. Non-CHD death rates per 100,000 inhabitants by age and gender.

Age range	Non-CHD death rates
	Male	Female
20–24	58.3	24.4
25–29	58.3	24.4
30–34	58.3	24.4
35–39	207.6	95.8
40–44	207.6	95.8
45–49	483.8	210.5
50–54	483.8	210.5
55–59	929.4	409.0
60–64	929.4	409.0
65–69	2130.6	1075.3
70–74	2130.6	1075.3
75–79	8229.8	6588.0
80–84	8229.8	6588.0
85+	8229.8	6588.0

Data source: Instituto Nacional de Estatistica, Statistics Portugal. Portuguese Life Table 2007–2009. http://www.ine.pt/ [Accessed October 1, 2013].

Table 3. Summary of efficacy data (% change).

Treatment change	Lipid parameter	% change (SE)	Notes
Addition of ezetimibe	TC	−17.3 (0.6)	Derived from Stein et al.7
	HDL-C	2.1	Derived from Stein et al.7
Switching from atorvastatin to rosuvastatin	TC	−8.0 (0.6)	Approximated from Schuster et al.8 and Ballantyne et al.9
	HDL-C	1.0	Rosuvastatin assumed to have the same variability as adding ezetimibe

HDL-C, high-density lipoprotein cholesterol; TC, total cholesterol.

Table 4. Summary of health state utilities.

Health state	Utility value	Notes
Healthy primary prevention	1	No previous history of CHD.
Non-fatal MI	0.76	Derived from Cook et al.16, van Nooten et al.17, Reiner et al.19
Angina pectoris	0.77	Derived from Cook et al.16, van Nooten et al.17, Reiner et al.19
Subsequent year CHD	0.808	Derived from NCEP18 and assumed to be the same as someone with stable angina
Healthy secondary prevention	0.808	Derived from NCEP18 and assumed to be the same as someone with stable angina.
Fatal MI	0
Non-CHD death	0

CHD, coronary heart disease; MI, myocardial infarction.

Table 5. Health states and medication costs.

Resource	Cost (€)
Events (annual cost)
Healthy primary prevention	141.40
Non-fatal MI	8010.01
Angina pectoris	4180.94
Fatal MI	6632.87
Subsequent year CHD	1790.49
Non-CHD death in primary state*	70.70
Non-CHD death in secondary state†	1087.98
Medication (daily cost)
Rosuvastatin 10 mg	0.80
Rosuvastatin 20 mg	1.23
Ezetimibe 10 mg	1.53

*Half the annual cost of primary prevention.

†Half the annual cost of the subsequent CHD year.

Table 6. Base-case results for the addition of ezetimibe to atorvastatin vs switching to rosuvastatin.

	A10/20	Switch to R10/20	A10/20 +  EZ10
Costs (€)
Discounted	11,131	14,511	16,572
Undiscounted	17,146	22,518	25,894
Life-years (LYs)
Discounted	9.55	9.67	9.80
Undiscounted	14.84	15.11	15.42
Quality-adjusted life-years (QALYs)
Discounted	8.70	8.81	8.93
Undiscounted	13.56	13.81	14.09
Incremental cost-effectiveness ratio (€/QALYs)	16,465

A10/20, atorvastatin 10 mg or 20 mg; R10/20, rosuvastatin 10 mg or 20 mg; EZ10, ezetimibe 10 mg.

Table 7. Sensitivity analysis results.

Variable	ICER (€/QALY)	% Change
Base case	16,465
Discount rate
0%	11,886	−28%
7%	18,566	13%
Annual CHD risk
−10%	17,826	8%
10%	15,349	−7%
Event costs
−20%	16,505	0.24%
20%	16,424	−0.25%
QALY estimates
−10%	17,102	4%
10%	15,873	−4%
Efficacy for TC
Switching to rosuvastatin
Lower 95% CI	14,829	−10%
Upper 95% CI	18,530	13%
Ezetimibe Addition
Lower 95% CI	18,588	13%
Upper 95% CI	14,778	−10%
Patient sub-group
Diabetes only	19,977	21%
CHD only	19,312	17%
CHD and diabetes	11,820	−28%

CHD, coronary heart disease; CI, confidence interval; ICER, incremental cost-effectiveness ratio; QALY, quality-adjusted life-year; TC, total cholesterol.

Stein E, Stender S, Mata P, et al. Achieving lipoprotein goals in patients at high risk with severe hypercholesterolemia: efficacy and safety of ezetimibe co-administered with atorvastatin. Am Heart J 2004;148:447-55

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