ShannonB validation

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External Validation

Comparison of the model structure with other models

  • Comparison of the structures of published diabetes models with Shannon B (incl. purpose of a model)
CDC Diabetes Cost- Effectiveness Group, 2002
071217 structure CDC Diabetes Cost Effectiveness Group 2002.jpg

Reference: CDC Diabetes Cost-effectiveness Group Cost-effectiveness of intensive glycemic control, intensified hypertension control, and serum cholesterol level reduction for type 2 diabetes.JAMA. 2002 May 15;287(19):2542-51.

The model by the CDC Diabetes Cost- Effectiveness Group shows the following differences:

  • The model by CDC doesn't include Macroalbuminuria
  • The CDC model doesn't offer the possibility for regression from Microalbuminuria to normal and from Macroalbiminuria to Microalbuminuria, as the Shannon A model does.
  • The second state of the CDC model "Clinical Nephropaty" is not taken into account in the Shannon B model.


Palmer et al, 2000
080327 structure Palmer et al Switzerland.jpg

Reference: The cost-effectiveness of different management strategies for type I diabetes: a Swiss perspective.Diabetologia. 2000 Jan;43(1):13-26.

The model by Palmer et al. includes many states the Shannon B model doesn't. The following shows the comparable differences between Shannon B and the model by Palmer et al.:

  • The model by Palmer et al. distinguishes two types of Dialysis: Haemodialysis and Peritoneal Dialysis.
  • It also distinguishes the states of non-specific mortality and ESRD- specific mortality, whereas the Shannon A model combines those two states.
  • The Palmer model takes Kidneytransplantation into account.
  • Another included state in the Palmer model ist "Graft failure".
  • The Palmer model doesn't allow for regression from "Macroalbuminuria" to "Microalbuminuria" and from "Microalbuminuria" to "No Nephropathy".


Palmer et al, 2003
071217 structure Palmer et al 2003.jpg

Reference: Palmer AJ, Annemans L, Roze S, Lamotte M, Rodby RA, Cordonnier DJ.An economic evaluation ofirbesartan in the treatment of patients with type 2 diabetes, hypertension and nephropathy:cost-effectiveness of Irbesartan in Diabetic Nephropathy Trial (IDNT) in the Belgian and French settings.Nephrol Dial Transplant. 2003 Oct;18(10):2059-66

  • The structure of this model is a little different from the Shannon A model. The following points are distinguishable:
    • This model regards ESRD with transplantation and dialysis whereas the Shannon A model takes only dialysis into acccount.
    • Also compared to the Shannon A model the state "doubling of serum creatinine" is taken into account.
    • Regression from ESRD with Transplant to ESRD with dialysis is possible
    • Direct transitions from the normal state, which means "no Nephropathy" to any other state are possible.


Palmer et al, 2006
071219 structure Palmer et al 2005.jpg

Reference: Palmer AJ, Chen R, Valentine WJ, Roze S, Bregman B, Mehin N, Gabriel S.Cost-consequence analysis in a French setting of screening and optimal treatment of nephropathy in hypertensive patients with type 2 diabetes.Diabetes Metab. 2006 Feb;32(1):69-76

The structure of the model by Palmer at al. shows the following differences to the structure of the Shannon A model:

  • The model by Palmer includes serveral states, which are not supported by the Shannon A model.
    • "early overt Nephropathy"
    • "advanced overt Nephropathy"
    • "doubling of serum creatinine"
    • "ESRD treated with Transplant"
  • This model doesn't allow regression, whereas the Shannon A model allows this.


Zhou et al, Diabetes Care, 2005
071206 structure Zhou et al.jpg

Reference: Zhou H, Isaman DJ, Messinger S, Brown MB, Klein R, Brandle M, Herman WH. A computer simulation model of diabetes progression, quality of life, and cost.Diabetes Care. 2005 Dec;28(12):2856-63.

The model by Zhou et al. has a very similar structure compared to the Shannon A model. Several differences are obvious:

  • The Zhou model regards transplantation and dialysis whereas the Shannon A model takes only dialysis into acccount.
  • In the Zhou model the progression from "normal", i.e. diabetes without nephropathy, to ESRD is a one-way course whereas the Shannon A modell allows for regression in the states "macroalbuminuria" and "microalbuminuria".
  • The Shannon A model takes Macroalbuminuria into account, whereas in the Zhou model it is called Proteinuria
  • In the Zhou model a direct progression from "normal" to "Proteinuria" is possible. The Shannon A model requires a progression to the state "Microalbuminuria" first.


Hoerger et al, 2004
071217 structure Hoerger et al, 2004.jpg

Reference: Hoerger TJ, Harris R, Hicks KA, Donahue K, Sorensen S, Engelgau M.Screening for type 2 diabetes mellitus: a cost-effectiveness analysis.Ann Intern Med. 2004 May 4;140(9):689-99.

  • The Hoerger model has a combined state "Low Microalbuminuria or high Albuminuria".
  • The Hoerger model does not allow death in early stages
  • In the Hoerger model no regression from any state is possible, whereas the Shannon A model allows for a regression from "Microalbuminuria" and "Macroalbuminuria"


Adarkwah et al, 2011
141111 structure Adarkwah et al, 2011.png

Reference: Adarkwah CC, Gandjour A, Akkerman M, Evers SM.Cost-effectiveness of angiotensin-converting enzyme inhibitors for the prevention of diabetic nephropathy in The Netherlands-a Markov model.PLoS One. 2011 Oct 11;6(10):e26139.

  • Both model have the same states
  • Adarkwah published in 2010 another similar model, we only discuss the newer publication
  • In the Adarkwah model no regression from any state is possible, whereas the Shannon A model allows a regression from "Microalbuminuria" and "Macroalbuminuria" as well as regression from "Microalbuminuria" to "No Nephropathy"


Chen et al, 2001
141111 structure Chen et al,2001.png

Reference: Chen TH, Yen MF, Tung TH.A computer simulation model for cost-effectiveness analysis of mass screening for Type 2 diabetes mellitus.Diabetes Res Clin Pract. 2001 Nov;54 Suppl 1:S37-42.

  • The Chen model has an extra state "Cardiovascular disease"
  • The Chen model doesn't offer the possibility of regressions
  • The Shannon A model takes Macroalbuminuria into account, whereas in the Chen model it is called Proteinuria
  • The Chen model does not allow death in early stage


CORE- Model, 2004

Reference: Palmer AJ, Roze S, Valentine WJ, Minshall ME, Foos V, Lurati FM, Lammert M, Spinas GA The CORE Diabetes Model: Projecting long-term clinical outcomes, costs and cost-effectiveness of interventions in diabetes mellitus (types 1 and 2) to support clinical and reimbursement decision-making.Curr Med Res Opin. 2004 Aug;20 Suppl 1:S5-26.

  • The CORE model regards different states of End- stage renal disease:
    • Haemodialysis
    • Peritoneal Dialysis
    • Kidney transplant

The Shannon A model only takes Dialysis into account.


Eddy and Schlessinger, 2003

Reference: Eddy DM, Schlessinger L.Archimedes: a trial-validated model of diabetes.Diabetes Care. 2003 Nov;26(11):3093-101.

  • The structure of the Archimedes model is not comparable to the stucture of toe Shannon A model:
    • It doesn't define states, but rather represents progression of the disease oin terms of underlying biological variables
    • Transition probabilities depend on each person and the different biological and behavioral factors

Comparison of transition probabilities with other models

  • Literature comparison with methods and transition probabilities of other published models

Shannon B

p_NonToNon p_NonToMicro p_NonToDeath p_MicroToNon p_MicroToMicro p_MicroToMacro p_MicroToDeath p_MacroToMicro p_MacroToMacro p_MacroToRenal p_MacroToDeath p_RenalToRenal p_RenalToDeath
# Forsblom et al., 1998;
Krolewski et al., 1995;
Ruggenenti et al., 2004
Bundesamt, 2014;
Roper et al., 2002
Gaede et al., 2004;
Newman et al., 2005;
Strippoli et al., 2004;
Bentata et al., 2016
# Adler et al., 2003;
Moriya et al., 2013;
Strippoli et al., 2004
Newman et al., 2005 Hovind et al., 2001;
Bentata et al., 2016
# Adler et al., 2003;
Brenner et al., 2001;
Lewis et al., 2001
Valmadrid et al., 2000 # Van Dijk et al., 2005
# = 1.0 - sum of other transitions leaving this state

CDC Diabetes Cost- Effectiveness Group, 2002

Transition probabilities are based on data of following studies:

Palmer et al, 2000

p_NonToMicroalburia p_MacroToESRD
DCCT Research Group, 1993 Krolewski et al, 1985

Other rates taken from:

Palmer et al, 2003

p_NonToDSC p_NonToESRD p_DSCToESRD p_NonToDeath p_DSCToDeath p_ESRDToDeath p_DialysisToTransplant
Lewis et al., 2001 Lewis et al., 2001 Lewis et al., 2001; Rodby et al., 2001 Lewis et al., 2001; Leibson et al., 1997 Lewis et al., 2001; Leibson et al., 1997 Lins R. Dialyse. Kluwer Handboek Gezondheidseconomie. Kluwer; 2000; 45: 66.1–66.49.; Combe et al., 2001; USRDS 2001 Lins R. Dialyse. Kluwer Handboek Gezondheidseconomie. Kluwer; 2000; 45: 66.1–66.49.; Combe et al., 2001; USRDS 2001

Palmer et al, 2006

Transition probabilities are based on data of following studies:

Moratlity rates taken from:

Zhou et al, Diabetes Care, 2005

p_NormalToMicro p_NormalToProteinuria p_MicroToProteinuria p_ProteinuriaToESRD(Dialysis) p_ESRD(Dialysis)ToESRD(Transplant) p_ESRD(Dialysis)ToDeath p_ESRD(Transplant)ToDeath
Gall et al., 1997 Ballard et al., 1998 Ravid et al., 1993 USRDS, 2000 USRDS, 2000 USRDS, 2000 USRDS, 2000

Hoerger et al, 2004

p_NormalToMicro p_MicroToNephropathy p_NephropathyToESRD
UKPDS 38; Eastman et al., 1997; Diabetes Control and Complications Trial, 1996 UKPDS 38; Diabetes Control and Complications Trial, 1996 Eastman et al., 1997; Humphrey et al., 1989

Adarkwah et al, 2011

p_NormalToMicro p_NormalToDeath p_MicroToMacro p_MicroToDeath p_MacroToESRD p_MacroToDeath p_ESRDToDeath
Strippoli et al., 2005 ; Strippoli et al., 2006 Bertoni et al., 2002; Statline, 2009; Lewis et al., 2001 Strippoli et al., 2005 ; Strippoli et al., 2006 Bertoni et al., 2002; Statline, 2009; Lewis et al., 2001 Lewis et al., 1993; Hasslacher et al., 2000; NIV, 2006; McIntosh et al., 2002; VA/DoD, 2003 Bertoni et al., 2002; Statline, 2009; Lewis et al., 2001 Renine, 2011

Chen et al., 2001

Transition probabilities are based on data of following studies:


CORE- Model, 2004

p_ProteinuriaToESRD p_ESRDToDeath
Ravid et al., 1993 Lewis et al., 1993, USRDS, 2000


Other transition probabilities were taken from UKPDS34.

Eddy and Schlessinger, 2003

Due to the different structure of the archimedes model of diabetes no transition probabilities can be enumerated.

Cross-Testing

  • Cross-testing of diabetes disease models


Model outcomes

  • Target: Compare the results of the Shannon A model to those of clinical long-term studies

Internal Validation

Input

medicine

cohort characteristics

The model offers the following cohort characteristics input parameters:

  • initial age (in years)
  • gender
  • duration of diabetes (in years)
  • smoker/ nonsmoker
  • HbA1c level (in %)
  • blood pressure (in mmHg)
  • BMI (in kg/m2)
  • Anti-hypertensive treatment
  • ACE inhibitors

economic evidence

The model allows the user to enter the desired discounting rate for the costs per year and a discounting rate for the outcome per year. Default values are 4,0%

Model

Complete transparency of the model structure and the model itself leads to an understanding of the developement processs --> "The documentation is the model!"

Output

Correct reporting of model results is performed by showing output tables and diagrams.

Face Validity

Face validity of Inputs

Here we have checked whether all input variables are active and that the model respons adequately to changes in the input.

Test Cohort

Following table lists the validation parameters and test results.

Face validity of Interpolation

Here we have checked whether the functions WINTERPOLATION and SINTERPOLATION are active and working correctly.

Patient Characteristics

One-Way Sensitivity Analysis

Tornado Diagrams

Direct comparison of the Shannon A and the Danube B models