Cost-effectiveness of dabigatran etexilate for stroke prevention in non-valvular atrial fibrillation. Applying RE-LY to clinical practice in Denmark

Figures & data

Table 1.  List of unit cost estimates applied in the model. In Euro (€).

Item	Baseline	Notes
Ischaemic stroke
3 month cost
Initial hospitalization	18,771
Other	1701
Total	20,472
Lifelong cost	1287	(per 3 months)
Heamorrhagic stroke
3 month cost
Initial hospitalization	16,665
Other	1359
Total	18,024
Lifelong cost (dependent only)	1028	(per 3 months)
Systemic embolism	3228	DRG 114 (kidney embolism)
Transient Ischemic Attack	2253	DRG 125 (TIA)
Acute Myocardial Infarction	8629	See text
Major extracranial haemorrhage
Fatal	3223	DRG 638 (GI bleed age >17 with complication)
Non-fatal/non-GI	1765	DRG 323 (Blood loss)
Non-fatal/GI	2623	DRG 640 (Uncomplicated GI bleed age >17)
Treatment switch/discontinuation	17	GP visit
INR monitoring (per year)	513	Per year. See Table 2
Dabigatran initiation	176	First 3 months. See Table 2
Dabigatran maintenance	17	Per year. See Table 2
Dabigatran	2.63	Per day
Warfarin	0.26	Per day (assume 2 × 2.5 mg dose of warfarin)
Aspirin	0.09	Per day (assume 75 mg)

Table 2.  Calculation of annual patient management cost on dabigatran and warfarin (Euro).

				Frequency	Contacts per year	Description	Annual cost (€)
Warfarin
GP (60%)	3rd party lab (50%)			4 weeks		Visit, test and shipment, follow-up^a	513
	Point of care instrument (50%)			3.5 weeks		Visit and follow-up^a	516
Hospital (40%)	Paper-based (27%)			5 weeks		Outpatient visit^b	1654
	AC clinic (70%)			5 weeks		Outpatient visit^b	1654
	Patient self-monitoring (3%)			2 weeks		Consultation by phone/internet^b	2068
Weighted average (warfarin)							975
Dabigatran
1 year	Specialist				1	Outpatient visit^b	159
	GP				3	Visit^a	52
	Total						211
2+ years	GP				1	Visit^a	17

AC, Anti-coagulation; GP, general practitioner.

^aUnit cost (€): visit 17.38, blood test and shipment 8.94, INR (PoC) 14.63, phone consultation 3.41, mail follow-up 5.47. Assumes 50% of follow-up is done face-to-face and 50% via phone/mail.

^bUnit cost (€): Outpatient visit 159.05, phone contact 79.52.

Table 3.  Baseline cost and quality-adjusted life-years per patient (life-long projection) by treatment strategy. Incremental cost-effectiveness ratio (warfarin compared to dabigatran).

	Sequential^a Dabigatran use	Warfarin
Direct costs/Patient
Drug costs and Monitoring (€)	8232	4935
Event costs (€)	8787	9727
Follow-up costs (€)	1733	2224
Total (€)	18,752	16,886
Incremental costs (€)	1866
Benefits/Patient (discounted at 2% per annum)
Expected number of events^b	0.47	0.55
Expected survival (years)	11.61	11.34
QALYs	8.59	8.32
Incremental QALY	0.27
ICER (Dabigatran vs warfarin)
Direct Costs (€) per QALY gained	6950

QALY, Quality adjusted life years; ICER, incremental cost effectiveness ratio.

^a150 mg b.i.d. for age below 80 then 110 mg b.i.d.

^bStroke, systemic embolism, and intracranial haemorrhage.

Table 4.  Univariate sensitivity analyses. Net present value of incremental cost and outcomes (dabigatran minus warfarin).

	Incremental costs (€)	Incremental QALY	ICER €/QALY
Baseline	1866	0.268	6950
INR monitoring
Variable cost estimate	2633	0.268	9806
Tariff based estimate	−1704	0.268	–
Centres achieving TTR < 57.1%	1760	0.288	6115
Centres achieving TTR 57.1–65.5%	1601	0.309	5175
Centres achieving TTR 65.5–72.6%	2434	0.188	12,923
Centres achieving TTR > 72.6%	2952	0.102	29,019
Cost of stroke
20% lower	2188	0.268	8149
20% higher	1544	0.268	5752
Cost of bleeding
20% lower	1854	0.268	6905
20% higher	1899	0.268	7075
20% higher (dabigatran only)	2016	0.268	7510
Discounting of future cost and outcomes (baseline 2% p.a.)
No discounting of future cost and outcomes	2114	0.263	8037
Discounting at 4% p.a.	2183	0.272	8023
Threshold analysis (annual cost of monitoring associated with equal lifetime cost of dabigatran and warfarin)
	Threshold monitoring cost (€/year)
Baseline (all centres)	744
Centres achieving TTR < 57.1%	731
Centres achieving TTR 57.1–65.5%	712
Centres achieving TTR 65.5–72.6%	815
Centres achieving TTR > 72.6%	879

p.a., per annum; QALY, Quality-adjusted life years; TTR, Time in therapeutic interval.

*Incremental cost per QALY gained (dabigatran compared to warfarin).

Figure 1.  Incremental cost and quality-adjusted life-years at varying level of thrombo-embologic and intra-cranial haemorrhage risk. Note: Each cluster represents a level of ICH risk from 0.4 to 1.6 events per 100 patient years. Each point represents a level of CHADS₂ from 0 (0.62 events/100 patient years) to 5–6 (2.77 event/100 patient years).