Validation of spatial microsimulation models: a proposal to adopt the Bland-Altman method

Model validation is recognised as crucial to microsimulation modelling. However, modellers encounter difficulty in choosing the most meaningful methods to compare simulated and actual values. The aim of this paper is to introduce and demonstrate a method employed widely in healthcare calibration stu...

Full description

Bibliographic Details
Main Authors: Timmins, Kate A., Edwards, Kimberley L.
Format: Article
Published: International Microsimulation Association 2016
Subjects:
Online Access:https://eprints.nottingham.ac.uk/41830/
_version_ 1848796362496278528
author Timmins, Kate A.
Edwards, Kimberley L.
author_facet Timmins, Kate A.
Edwards, Kimberley L.
author_sort Timmins, Kate A.
building Nottingham Research Data Repository
collection Online Access
description Model validation is recognised as crucial to microsimulation modelling. However, modellers encounter difficulty in choosing the most meaningful methods to compare simulated and actual values. The aim of this paper is to introduce and demonstrate a method employed widely in healthcare calibration studies. The ‘Bland-Altman plot’ consists of a plot of the difference between two methods against the mean (x-y versus x+y/2). A case study is presented to illustrate the method in practice for spatial microsimulation validation. The study features a deterministic combinatorial model (SimObesity), which modelled a synthetic population for England at the ward level using survey (ELSA) and Census 2011 data. Bland-Altman plots were generated, plotting simulated and census ward-level totals for each category of all constraint (benchmark) variables. Other validation metrics, such as R2, SEI, TAE and RMSE, are also presented for comparison. The case study demonstrates how the Bland-Altman plots are interpreted. The simple visualisation of both individual- (ward-) level difference and total variation gives the method an advantage over existing tools used in model validation. There still remains the question of what constitutes a valid or well-fitting model. However, the Bland Altman method can usefully be added to the canon of calibration methods.
first_indexed 2025-11-14T19:46:47Z
format Article
id nottingham-41830
institution University of Nottingham Malaysia Campus
institution_category Local University
last_indexed 2025-11-14T19:46:47Z
publishDate 2016
publisher International Microsimulation Association
recordtype eprints
repository_type Digital Repository
spelling nottingham-418302020-05-04T17:52:18Z https://eprints.nottingham.ac.uk/41830/ Validation of spatial microsimulation models: a proposal to adopt the Bland-Altman method Timmins, Kate A. Edwards, Kimberley L. Model validation is recognised as crucial to microsimulation modelling. However, modellers encounter difficulty in choosing the most meaningful methods to compare simulated and actual values. The aim of this paper is to introduce and demonstrate a method employed widely in healthcare calibration studies. The ‘Bland-Altman plot’ consists of a plot of the difference between two methods against the mean (x-y versus x+y/2). A case study is presented to illustrate the method in practice for spatial microsimulation validation. The study features a deterministic combinatorial model (SimObesity), which modelled a synthetic population for England at the ward level using survey (ELSA) and Census 2011 data. Bland-Altman plots were generated, plotting simulated and census ward-level totals for each category of all constraint (benchmark) variables. Other validation metrics, such as R2, SEI, TAE and RMSE, are also presented for comparison. The case study demonstrates how the Bland-Altman plots are interpreted. The simple visualisation of both individual- (ward-) level difference and total variation gives the method an advantage over existing tools used in model validation. There still remains the question of what constitutes a valid or well-fitting model. However, the Bland Altman method can usefully be added to the canon of calibration methods. International Microsimulation Association 2016-05-12 Article PeerReviewed Timmins, Kate A. and Edwards, Kimberley L. (2016) Validation of spatial microsimulation models: a proposal to adopt the Bland-Altman method. International Journal of Microsimulation, 9 (2). pp. 106-122. ISSN 1747-5864 Validation Bland Altman Spatial microsimulation http://www.microsimulation.org/IJM/V9_2/IJM_9_2_2016_Timmins.pdf
spellingShingle Validation
Bland Altman
Spatial microsimulation
Timmins, Kate A.
Edwards, Kimberley L.
Validation of spatial microsimulation models: a proposal to adopt the Bland-Altman method
title Validation of spatial microsimulation models: a proposal to adopt the Bland-Altman method
title_full Validation of spatial microsimulation models: a proposal to adopt the Bland-Altman method
title_fullStr Validation of spatial microsimulation models: a proposal to adopt the Bland-Altman method
title_full_unstemmed Validation of spatial microsimulation models: a proposal to adopt the Bland-Altman method
title_short Validation of spatial microsimulation models: a proposal to adopt the Bland-Altman method
title_sort validation of spatial microsimulation models: a proposal to adopt the bland-altman method
topic Validation
Bland Altman
Spatial microsimulation
url https://eprints.nottingham.ac.uk/41830/
https://eprints.nottingham.ac.uk/41830/