This is supplementary material for submission AHEA-D-14-00025 and is for online publication only. The below table provides further detail on the inputs used in the economic model and the distributions used for sensitivity analysis.
Journal of Applied Health Economics and Health Policy: Cost effectiveness of renal denervation therapy for the treatment of resistant hypertension in the UK
Daniel Gladwell, MSc, BresMed, North Church House, Sheffield, S1 2DW
Thea Henry, BSc, BresMed, North Church House, Sheffield, S1 2DW
Mark Cook, Medtronic Ltd, Croxley Green Business Park, Watford, WD18 8WW
Ron Akehurst, BSc, Hon MFPHM, BresMed, North Church House, Sheffield, S1 2DW
Thea Henry:
Tel: +44 (0) 114 309 4372
Fax: +44 (0) 114 270 0422
Table 6: Parameters and distributions used for sensitivity analysis
Description / Distribution / Base Case value * / SourceStarting age / Normal / 58 (1.664) / [11]
Proportion of females / Beta / 0.43 (0.285,0.571) / [11]
Proportion of current smokers / Beta / 0.16 (0.074,0.271) / TreeAge Model*
Alcohol oz/week / Normal / 8 (1.609)
Baseline systolic blood pressure / Normal / 178 (2.496) / [11]
HDL / Normal / 53 (2.496) / [11]
LDL / Normal / 108 (4.438) / [11]
Heart rate / Normal / 73 (1.525) / TreeAge Model**
Vital capacity for men / Normal / 4.6 (0.055) / TreeAge Model**
Vital capacity for women / Normal / 3.6 (0.194) / TreeAge Model**
Triglycerides / Normal / 187.5 (8.321) / TreeAge Model**
GGT females / Normal / 16 (1.941) / TreeAge Model**
GGT males / Normal / 31 (4.715) / TreeAge Model**
SBP reduction in treatment arm / Normal / 14.13 (3.561) / TreeAge Model**
Proportion of women in menopause / Normal / 0.8 (0.011) / TreeAge Model**
% of patients on anti-hypertensive meds / Normal / 1 (0.014) / TreeAge Model**
Total cholesterol / Normal / 198.5 (2.753) / TreeAge Model**
Proportion of patients with diabetes mellitus / Beta / 0.34 (0.218,0.473) / TreeAge Model**
Proportion of patients with valve disease / Beta / 0.019 (0.001,0.066) / TreeAge Model**
Proportion of patients with cardiomegaly / Beta / 0.208 (0.11,0.328) / TreeAge Model**
Proportion of patients with family history of MI / Beta / 0.165 (0.139,0.193) / TreeAge Model**
Proportion of patients with LVH / Normal / 0.208 (0.003) / TreeAge Model**
Proportion of patients with atrial fibrillation / Normal / 0.037 (0.001) / TreeAge Model**
Relative risk of death following stroke-CHF / Normal / 2.189 (0.219) / [14,36]
Relative risk of death following stroke-MI / Normal / 2.99 (0.321) / [15]
Relative risk of death following stroke- first 30 days following MI / Normal / 2.27 (0.449) / [15]
Probability of HF in first 30 days in MI health state / Beta / 0.231 (0.009,0.363) / [48]
Probability of death in first 30 days following stroke / Beta / 0.126 (0.009,0.363) / [13]
Probability of having an unstable AP / Beta / 0.15 (0.016,0.392) / [33,34]
Relative risk of ESRD (cons, SBP) / Normal / [35]
Constant / Normal / -3.11 (0.311)
SBP / Normal / 0.039 (0.004)
Relative risk of a stroke following ESRD / Normal / [49]
%female*%africanamerican females / Normal / 6.2 (0.714)
%female(1-%africanamerican females) / Normal / 9.7 (0.765)
(1-%female)*%africanamerican males / Normal / 4.4 (0.561)
(1-%female)(1-%africanamerican males) / Normal / 6.1 (0.765)
CHD Incidence in women: Weibull (SBP, age, sex, menopausal status,TC, HDL,TG, DM, smoking, medications, alcohol) / [33,34]
Constant / Normal / 20.972 (2.097)
LN(SBP) / Normal / -2.245 (0.224)
Age / Normal / -0.062 (0.006)
Menopause / Normal / -3.852 (0.385)
Age*menopause / Normal / 0.073 (0.007)
LN(Total Cholesterol/HDL) / Normal / -0.626 (0.063)
Number of hypertensive medications / Normal / -0.01 (0.001)
Diabetes mellitus / Normal / -0.524 (0.052)
Smoker / Normal / -0.378 (0.038)
LN(Triglycerides) / Normal / -0.269 (0.027)
Units of alcohol / Normal / 0.053 (0.005)
Scale parameter for chdweibull survival model for women / Normal / 0.747 (0.075)
CHD Incidence in men: Weibull (SBP, age, sex,TC, HDL, DM, smoking, medications, alcohol) / [33,34]
Constant / Normal / 12.787 (1.279)
LN(SBP) / Normal / -1.016 (0.102)
Age / Normal / -0.041 (0.004)
LN(total cholesterol/HDL) / Normal / -0.949 (0.095)
Number of hypertensive medications / Normal / -0.016 (0.002)
Diabetes mellitus / Normal / -0.441 (0.044)
Smoker / Normal / -0.604 (0.06)
Scale parameter for chdweibull survival model for men / Normal / 0.776 (0.078)
MI Incidence: Exponential (SBP, age, TG, HDL, LDL, DM, γ-GT, smoking) / [46]
Constant / Normal / -31.688 (3.169)
age / Normal / 0.098 (0.01)
Triglycerides / Normal / -0.023 (0.002)
LN(Triglycerides) / Normal / 5.753 (0.575)
HDL / Normal / -0.411 (0.041)
LDL / Normal / 0.015 (0.002)
SBP / Normal / 0.014 (0.001)
GGT / Normal / -0.026 (0.003)
Smoker / Normal / 0.755 (0.075)
Diabetes mellitus / Normal / 0.583 (0.058)
Family history of MI / Normal / 0.415 (0.042)
HDL*LN(HDL) / Normal / 0.09 (0.009)
Triglycerides*HDL / Normal / -0.0004 (0.00004)
Triglycerides*GGT / Normal / 0.0001 (0.00001)
Stroke incidence in women: Exponential (SBP, age, CVD, LVH, DM, smoking, AF) / [47]
SBP / Normal / 0.016 (0.002)
SBP adjustment** / Normal / 0.0003 (0.00003)
Age / Normal / 0.07 (0.007)
CVD / Normal / 0.44 (0.044)
LVH / Normal / 0.806 (0.081)
Smoker / Normal / 0.542 (0.054)
Atrial fibrillation / Normal / 1.117 (0.112)
Diabetes mellitus / Normal / 0.56 (0.056)
m value for stroke for women*** / Normal / 7.69 (0.769) / [50]
Stroke incidence in men: Exponential (SBP, age, CVD, LVH, DM, smoking, AF)
Normal / [47]
SBP / Normal / 0.015 (0.002)
SBP adjustment** / Normal / 0.0002 (0.00002)
age / Normal / 0.049 (0.005)
CVD / Normal / 0.546 (0.055)
LVH / Normal / 0.786 (0.079)
smoker / Normal / 0.522 (0.052)
Atrial fibrillation / Normal / 0.6 (0.06)
Diabetes mellitus / Normal / 0.343 (0.034)
m value for stroke for men*** / Normal / 6.025 (0.603) / [50]
Primary HF Incidence in women: Exponential (SBP, age, sex, DM, LVH, cardiomegaly, vital capacity, heart rate, CHD, valve disease) / [51]
Constant / Normal / -5.5 (0.55)
SBP / Normal / 0.003 (0)
Age / Normal / 0.022 (0.002)
LVH / Normal / 1.007 (0.101)
Vital capacity in women*100 / Normal / -0.009 (0.001)
MI / Normal / 1.536 (0.154)
Valve disease / Normal / 1.245 (0.125)
Diabetes mellitus / Normal / 1.428 (0.143)
Cardiomegaly / Normal / 0.479 (0.048)
Valve disease*diabetes mellitus / Normal / -0.929 (0.093)
Heart rate / Normal / 0.009 (0.001)
Primary HF Incidence in men: Exponential (SBP, age, sex, DM, LVH, cardiomegaly, vital capacity, heart rate, CHD, valve disease) / [51]
Constant / Normal / -7.361 (0.736)
SBP / Normal / 0.007 (0.001)
Age / Normal / 0.031 (0.003)
LVH / Normal / 0.843 (0.084)
Vital capacity in men * 100 / Normal / 0.003 (0.0003)
MI / Normal / 1.533 (0.153)
Valve disease / Normal / 0.887 (0.089)
Diabetes mellitus / Normal / 0.238 (0.024)
Cardiomegaly / Normal / 0.797 (0.08)
Heart rate / Normal / 0.014 (0.001)
Costs
AP
Stable AP / Gamma / £5.724 (0.572) / NHS Reference Costs (2011-12) HRG code: PA22Z [28]
Initial unstable AP / Gamma / £535.69 (53.569)
Unstable AP / Gamma / £5.724 (0.572)
ESRD / NHS Reference Costs (2011-12) [28], NHS BT: Fact Sheet 7 (2009)[30]
ESRD patient without diabetes / Gamma / £2983.333 (298.333)
ESRD patients with diabetes / Gamma / £3287.033 (328.703)
HF / NHS Reference Costs (2011-12) HRG code: EB03H/EB03I [28]
Initial HF / Gamma / £1211.075 (121.108)
Initial HF with complications / Gamma / £2006.7 (200.67)
HF year 1 / Gamma / £53.814 (5.381)
HF year 2 and following / Gamma / £53.814 (5.381)
MI / NHS Reference Costs (2011-12) HRG code: EB10Z [28]
Acute MI / Gamma / £1421.789 (142.179)
Post MI / Gamma / £53.814 (5.381)
Stroke / [29]
Acute stroke / Gamma / £10726.204 (1072.62)
Post stroke Year 1 / Gamma / £191.464 (19.146)
Post stroke Year 2 and following / Gamma / £191.464 (19.146)
Hypertension –SoC / Gamma / £5.797 (0.58) / BNF63 + PSSRU Unit Costs 2012[31, 32]
Renal denervation therapy / Gamma / £4500 (450) / Data on file - Medtronic plc (2013)
Utilities
Utility for AP / Beta / 0.767 (0.077) / [26]
Utility for stable AP / Beta / 0.808 (0.081) / [23, 26]
Utility for unstable AP / Beta / 0.77 (0.038) / [24, 26]
Utility for ESRD / Beta / 0.72 (0.06) / [27]
Utility for MI (months 7+) / Beta / 0.88 (0.041) / [7]
Utility for MI (months 1-6) / Beta / 0.76 (0.018) / [23, 24]
Utility for stroke / Beta / 0.629 (0.063) / [23]
Utility for HF / Beta / 0.683 (0.01) / [25]
AP= Angina Pectoris; SoC= Standard of Care;BNF = British National Formulary; ESRD=end-stage renal disease; HDL = high density lipoprotein; HF= heart failure; HRG = Healthcare Research Group; LDL= low density lipoprotein; LVH=left Ventricular Hypertrophy; NHS, National Health Service; PSSRU = Personal Social Services Research Unit; SBP = Systolic blood pressure; GGT= gamma-glutamyltransferase; CHF=coronary heart failure; MI= myocardial infarction; tc=Total Cholesterol; tg=Triglycerides; dm=Diabetes Mellitus
* Values given in parenthesis are standard errors where a normal or gamma distribution has been applied. Where a beta distribution has been applied, values in parenthesis are alpha and beta.
** As noted in the main text, the economic model was adapted from an existing model based in TreeAge. Where the original source of the data is unclear, the source has been stated as the originating model.
***SBP adjustment in addition where 110<SBP>200; males 0.00019*(SBP-110)*(200-SBP); females 0.00026*(SBP-110)*(200-SBP).
****Wolf et al (1991) [51] m value estimated using regression equation based on mean explanatory variable values.
A multiplication factor (1+z) was used for all other transition probabilities in the PSA where z~N(0,0.1)
Additional references:
46. Voss R, Cullen P, Schulte H, Assmann G. Prediction of risk of coronary events in middle-aged men in the Prospective Cardiovascular Munster Study (PROCAM) using neural networks. International journal of epidemiology. 2002 Dec;31(6):1253-62; discussion 62-64.
47.D'Agostino RB, Wolf PA, Belanger AJ, Kannel WB. Stroke risk profile: adjustment for antihypertensive medication. The Framingham Study. Stroke; a journal of cerebral circulation. 1994 Jan;25(1):40-3.
48.Velagaleti RS, Pencina MJ, Murabito JM, Wang TJ, Parikh NI, D'Agostino RB, et al. Long-term trends in the incidence of heart failure after myocardial infarction. Circulation. 2008 Nov 11;118(20):2057-62.
49. Seliger SL, Gillen DL, Longstreth WT, Jr., Kestenbaum B, Stehman-Breen CO. Elevated risk of stroke among patients with end-stage renal disease. Kidney international. 2003;64(2):603-9.
50. Wolf PA, D'Agostino RB, Belanger AJ, Kannel WB. Probability of stroke: a risk profile from the Framingham Study. Stroke 1991;22(3):312-8.
51. Kannel WB, D'Agostino RB, Silbershatz H, Belanger AJ, Wilson PW, Levy D. Profile for estimating risk of heart failure. Archives of internal medicine. 1999;159(11):1197-204.