Arie Rahadi, Rizki Tsalatshita Khair Mahardya, Putri Listiani, Eva Herlinawaty, Ryan Rachmad Nugraha, Dani Ramdhani Budiman, Christian Suharlim
{"title":"Calibration of transition probabilities to model survival of adjuvant trastuzumab for early breast cancer in Indonesia.","authors":"Arie Rahadi, Rizki Tsalatshita Khair Mahardya, Putri Listiani, Eva Herlinawaty, Ryan Rachmad Nugraha, Dani Ramdhani Budiman, Christian Suharlim","doi":"10.1017/S0266462325000157","DOIUrl":null,"url":null,"abstract":"<p><strong>Objectives: </strong>Cost-effectiveness models fully informed by real-world epidemiological parameters yield the best results, but they are costly to obtain. Model calibration using real-world data/evidence (RWD/E) on routine health indicators can provide an alternative to improve the validity and acceptability of the results. We calibrated the transition probabilities of the reference chemotherapy treatment using RWE on patient overall survival (OS) to model the survival benefit of adjuvant trastuzumab in Indonesia.</p><p><strong>Methods: </strong>A Markov model comprising four health states was initially parameterized using the reference-treatment transition probabilities, obtained from published international evidence. We then calibrated these probabilities, targeting a 2-year OS of 86.11 percent from the RWE sourced from hospital registries. We compared projected OS duration and life-years gained (LYG) before and after calibration for the Nelder-Mead, Bound Optimization BY Quadratic Approximation, and generalized reduced gradient (GRG) nonlinear optimization methods.</p><p><strong>Results: </strong>The pre-calibrated transition probabilities overestimated the 2-year OS (92.25 percent). GRG nonlinear performed best and had the smallest difference with the RWD/E OS. After calibration, the projected OS duration was significantly lower than their pre-calibrated estimates across all optimization methods for both standard chemotherapy (~7.50 vs. 11.00 years) and adjuvant trastuzumab (~9.50 vs. 12.94 years). LYG measures were, however, similar (~2 years) for the pre-calibrated and calibrated models.</p><p><strong>Conclusions: </strong>RWD/E calibration resulted in realistically lower survival estimates. Despite the little difference in LYG, calibration is useful to adapt external evidence commonly used to derive transition probabilities to the policy context, thereby enhancing the validity and acceptability of the modeling results.</p>","PeriodicalId":14467,"journal":{"name":"International Journal of Technology Assessment in Health Care","volume":"41 1","pages":"e18"},"PeriodicalIF":2.6000,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11955306/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"International Journal of Technology Assessment in Health Care","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1017/S0266462325000157","RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"HEALTH CARE SCIENCES & SERVICES","Score":null,"Total":0}
引用次数: 0
Abstract
Objectives: Cost-effectiveness models fully informed by real-world epidemiological parameters yield the best results, but they are costly to obtain. Model calibration using real-world data/evidence (RWD/E) on routine health indicators can provide an alternative to improve the validity and acceptability of the results. We calibrated the transition probabilities of the reference chemotherapy treatment using RWE on patient overall survival (OS) to model the survival benefit of adjuvant trastuzumab in Indonesia.
Methods: A Markov model comprising four health states was initially parameterized using the reference-treatment transition probabilities, obtained from published international evidence. We then calibrated these probabilities, targeting a 2-year OS of 86.11 percent from the RWE sourced from hospital registries. We compared projected OS duration and life-years gained (LYG) before and after calibration for the Nelder-Mead, Bound Optimization BY Quadratic Approximation, and generalized reduced gradient (GRG) nonlinear optimization methods.
Results: The pre-calibrated transition probabilities overestimated the 2-year OS (92.25 percent). GRG nonlinear performed best and had the smallest difference with the RWD/E OS. After calibration, the projected OS duration was significantly lower than their pre-calibrated estimates across all optimization methods for both standard chemotherapy (~7.50 vs. 11.00 years) and adjuvant trastuzumab (~9.50 vs. 12.94 years). LYG measures were, however, similar (~2 years) for the pre-calibrated and calibrated models.
Conclusions: RWD/E calibration resulted in realistically lower survival estimates. Despite the little difference in LYG, calibration is useful to adapt external evidence commonly used to derive transition probabilities to the policy context, thereby enhancing the validity and acceptability of the modeling results.
期刊介绍:
International Journal of Technology Assessment in Health Care serves as a forum for the wide range of health policy makers and professionals interested in the economic, social, ethical, medical and public health implications of health technology. It covers the development, evaluation, diffusion and use of health technology, as well as its impact on the organization and management of health care systems and public health. In addition to general essays and research reports, regular columns on technology assessment reports and thematic sections are published.