Modeling the economic impact of medication adherence in type 2 diabetes: a theoretical approach

Figures & data

Figure 1 Base case model of fundamental T2D health states.

Notes: *Death = All-cause mortality adjusted for T2D/CVD severity.
Abbreviations: IDM, injectable diabetes medication; OAD, oral antidiabetic drug; CVD, cardiovascular disease; CAD, coronary artery disease; ESRD, end-stage renal disease.

Figure 2 Adherence-adjusted approach at modeling T2D.

Notes: *Death = All-cause mortality adjusted for T2D/CVD severity.
Abbreviations: IDM, injectable diabetes medication; OAD, oral antidiabetic drug; CVD, cardiovascular disease; CAD, coronary artery disease; ESRD, end-stage renal disease; MPR, medication possession ratios.

Table 1 Summary of modeled results: IDM vs OADs*

IDM vs OADs	IDM	OADs	Difference
Analysis 1
Clinical outcomes, years
Life expectancy (discounted)	16.376 (0.18)	15.815 (0.17)	0.561 (0.01)
Quality-adjusted life expectancy	10.554 (0.10)	9.631 (0.09)	0.923 (0.01)
Complication rates, cumulative incidence, % (SD)
End-stage renal disease	17.6 (1.1)	18.1 (1.2)	0.5 (0.1)
Amputation	13.4 (1.1)	13.8 (1.0)	0.4 (0.1)
CVD/CAD	22.1 (1.3)	22.7 (1.5)	0.6 (0.2)
Nephropathy	36.3 (1.6)	37.2 (1.6)	0.9 (0.0)
Stroke	9.1 (0.9)	9.4 (1.0)	0.3 (0.1)
Neuropathy	46.3 (1.6)	47.8 (1.5)	1.5 (0.1)
Retinopathy	19.9 (1.3)	19.8 (1.3)	0.1 (0.0)
Major hypoglycemia	63.8 (1.9)	55.5 (1.8)	8.3 (0.1)
Cost outcomes, US$
Direct medical costs	241,304 (8122)	238,906 (8218)	2,398 (96)
Pharmacy costs	60,551 (2231)	51,783 (2004)	8,768 (227)
Total lifetime costs	301,855 (8933)	290,689 (8690)	11,166 (243)
$/QALY (IDM vs OADs)	12,097
Analysis 2
Clinical outcomes, years
Life expectancy (discounted)	16.562 (0.18)	16.231 (0.17)	0.331 (0.01)
Quality-adjusted life expectancy	10.848 (0.10)	10.173 (0.01)	0.675 (0.09)
Complication rates, cumulative incidence, % (SD)
End-stage renal disease	17.0 (1.1)	17.3 (1.0)	0.3 (0.1)
Amputation	13.3 (1.0)	13.6 (1.2)	0.3 (0.2)
CVD/CAD	21.9 (1.4)	22.1 (1.3)	0.2 (0.1)
Nephropathy	34.7 (1.4)	35.0 (1.4)	0.3 (0.0)
Stroke	8.8 (0.8)	8.9 (0.8)	0.1 (0.0)
Neuropathy	45.8 (1.7)	46.6 (1.7)	0.8 (0.0)
Retinopathy	18.5 (1.2)	18.2 (1.1)	0.3 (0.1)
Major hypoglycemia	59.8 (1.8)	48.4 (1.6)	11.4 (0.2)
Cost outcomes, US$
Direct medical costs	244,112 (8034)	241,037 (8026)	3,075 (8)
Pharmacy costs	62,788 (2319)	54,900 (1996)	7,888 (323)
Total lifetime costs	306,900 (9155)	295,937 (8716)	10,963 (439)
$/QALY (IDM vs OADs)	16,241

Abbreviations: IDM, injectable diabetes medication; OAD, oral antidiabetic drug; CVD, cardiovascular disease; CAD, coronary artery disease; QALY, quality-adjusted life-year.

* Means with standard deviations (SD) from 1000 patients in each of 1000 cohort simulations are provided.