The cost effectiveness of rapid-acting insulin aspart compared with human insulin in type 2 diabetes patients: an analysis from the Japanese third-party payer perspective

Figures & data

Figure 1.  Data sources for event incidence over the model time horizon.

Table 1.  Baseline cohort characteristics from the NICE study.

Characteristic	Mean value (n = 325)
Age (years)	58
Proportion male	0.49
Fasting plasma glucose (mg/dl)	130
Postprandial plasma glucose (mg/dl)	200
HbA1c (%)	7.5
Systolic blood pressure (mmHg)	117
Diastolic blood pressure (mmHg)	68
Body mass index (kg/m^2)	22.7
Low-density lipoprotein (mg/dl)	108
High-density lipoprotein (mg/dl)	62
Triglycerides (mg/dl)	128
Proportion current smokers	0.5

HbA_1c, glycated haemoglobin.

Table 2.  Event and pharmacy costs used in the modelling analysis.

Item	Cost in JPY (95% confidence interval)
Unit of insulin aspart	7.62
Unit of human insulin	7.45
Unit of basal insulin (Novolin)	3.73
Myocardial infarction event	2,011,380 (1,727,710–2,295,040)
Cerebral infarction event	1,393,160 (1,386,660–1,399,656)
Coronary artery bypass graft	2,466,200 (1,316,459–3,615,950)
Percutaneous coronary intervention	3,289,040 (2,725,142–3,852,947)
Severe hypoglycaemia	40,056

Insulin cost data supplied by Novo Nordisk A/S. Event cost data supplied by the Japanese Medical Data Centre. JPY, 2008 Japanese yen.

Table 3.  Quality of life utilities.

State	Utility	Reference
Diabetes, no complications	0.814	16
MI, year of event	0.685	16
MI, years 2+ after event	0.736	16
Cerebral infarction, year of event	0.643	16
Cerebral infarction, years 2+ after event	0.545	16
CABG, year of event	0.814	Assumed
CABG, years 2+ after event	0.814	Assumed
PCI, year of event	0.814	Assumed
PCI, years 2+ after event	0.814	Assumed
Severe hypoglycaemia, year of event	0.802	16,20

MI, myocardial infarction; CABG, coronary artery bypass graft; PCI, percutaneous coronary intervention.

Figure 2.  Survival curve showing proportion of patients alive in the insulin aspart and regular human insulin arms.

Table 4.  Within-trial and post-trial cost and effectiveness outcomes.

Outcome	Within-trial outcomes			Within-trial and post-trial outcomes
	IAsp	HI	IAsp − HI	IAsp	HI	IAsp − HI
Life expectancy (years)	4.688	4.684	+0.005	8.546	8.503	+0.043
Quality-adjusted life expectancy (QALYs)	3.800	3.776	+0.023	6.942	6.879	+0.062
Mean per-patient pharmacy cost (JPY)	346,608	278,468	+68,140	638,269	506,817	+131,453
Mean per-patient adverse event cost (JPY)	134,978	316,249	−181,271	288,203	672,578	−384,376
Total cost (JPY)	481,586	594,717	−113,131	926,472	1,179,395	−252,923
ICER (JPY/QALY)	Insulin aspart dominant			Insulin aspart dominant

HI, regular human insulin; IAsp, insulin aspart; ICER, incremental cost-effectiveness ratio; JPY, 2008 Japanese yen; QALY, quality-adjusted life-year.

Figure 3.  Pharmacy and event costs in the insulin aspart and regular human insulin arms over a 10-year time horizon.

Figure 4.  Break-even analysis showing (A) incremental costs, (B) net health benefit and (C) incremental QALE over a range of the observed cardiovascular and mortality benefits of insulin aspart when compared with regular human insulin (over a 5-year time horizon).

Table 5.  Sensitivity analyses (5-year base case).

Parameter	Value	Quality-adjusted life expectancy (QALYs)			Total cost (JPY)			ICER (JPY/QALY)
		IAsp	HI	IAsp − HI	IAsp	HI	IAsp − HI
Base case	N/A	3.800	3.776	0.023	481,586	594,717	−113,131	Insulin aspart dominant
Cost and clinical discount rate	0%	4.034	4.008	0.025	514,126	638,566	−124,440	Insulin aspart dominant
Cost and clinical discount rate	6%	3.579	3.558	0.021	451,023	553,646	−102,623	Insulin aspart dominant
Pharmacy costs	JPY 0	3.800	3.776	0.023	134,978	316,249	−181,271	Insulin aspart dominant
Pharmacy costs	50% of base case	3.800	3.776	0.023	308,282	455,483	−147,201	Insulin aspart dominant
Pharmacy costs	200% of base case	3.800	3.776	0.023	828,194	873,185	−44,991	Insulin aspart dominant
All complication costs	JPY 0	3.800	3.776	0.023	346,608	278,468	68,140	2,947,310
All complication costs	50% of base case	3.800	3.776	0.023	414,097	436,592	−22,496	Insulin aspart dominant
All complication costs	200% of base case	3.800	3.776	0.023	616,564	910,965	−294,401	Insulin aspart dominant
Cost of MI, CI, CABG and PCI	Lower 95% confidence interval bound	3.800	3.776	0.023	459,275	542,581	−83,306	Insulin aspart dominant
Cost of MI, CI, CABG and PCI	Upper 95% confidence interval bound	3.800	3.776	0.023	503,896	646,852	−142.956	Insulin aspart dominant
All HRQoL utilities	0.814	3.816	3.812	0.004	481,586	594,717	−113,131	Insulin aspart dominant
CABG and PCI utilities	105% of base case	3.802	3.780	0.021	481,586	594,717	−113,131	Insulin aspart dominant
MI incidence	Same in both arms	3.794	3.776	0.017	532,529	594,717	−62,187	Insulin aspart dominant
CI incidence	Same in both arms	3.788	3.776	0.012	508,769	594,717	−85,948	Insulin aspart dominant
Incidence of mortality and all cardiovascular complications and procedures	0% of benefit*	3.777	3.776	0.001	641,695	594,717	46,978	47,253,567
	20% of benefit*	3.782	3.776	0.005	609,673	594,717	14,956	2,762,557
	40% of benefit*	3.786	3.776	0.010	577,651	594,717	−17,066	Insulin aspart dominant
	60% of benefit*	3.791	3.776	0.014	545,629	594,717	−49,088	Insulin aspart dominant
	80% of benefit*	3.795	3.776	0.019	513,607	594,717	−81,109	Insulin aspart dominant

CABG, coronary artery bypass graft; CI, cerebral infarction; HI, regular human insulin; HRQoL, health-related quality of life; IAsp, insulin aspart; ICER, incremental cost-effectiveness ratio; JPY, 2008 Japanese yen; MI, myocardial infarction; PCI, percutaneous coronary intervention; QALYs, quality-adjusted life-years. *These sensitivity analyses are also presented in Figure 4 and represent a scenario in which the cardiovascular and mortality event rates observed in the insulin aspart arm of the NICE study were increased step-wise toward those observed in the regular human insulin arm, hence reducing the modelled benefit of insulin aspart versus regular human insulin.

Takeda A. [The policy for diabetes of local government]. Nippon Rinsho 2002;60(Suppl 10):608-612

 Google Scholar

Howey DC, Bowsher RR, Brunelle RL, et al. [Lys(B28), Pro(B29)]-human insulin. A rapidly absorbed analogue of human insulin. Diabetes 1994;43:396-402

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