Validation of the kidney failure risk equation and its impact on referral strategies for chronic kidney disease: protocol for a retrospective cohort study using national claims and laboratory data in Thailand
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
Introduction: Chronic kidney disease (CKD) is highly prevalent in Thailand and imposes a growing burden on the health system driven by limited nephrology capacity and high rates of unplanned dialysis. The Kidney Failure Risk Equation (KFRE) estimates the risk of progression to kidney failure on age, sex, estimated glomerular filtration rate (eGFR), and urine albumin-to-creatinine ratio. This study aims to validate and, if required, recalibrate the 4-variable KFRE for the Thai population and to assess its potential impact of KFRE-guided referral strategies on clinical care and health system performance.
Methods and Analysis: We will conduct a retrospective cohort study using linked, de-identified national health databases covering approximately 70% of the Thai population. Adult patients with CKD stages 3–5 will be included. KFRE performance will be evaluated at 2 and 5 years for discrimination and calibration. If miscalibration is identified, the model will be recalibrated using Cox-based methods. Simulations (1,000 iterations) indicated that approximately 920 kidney failure events by 5 years would be required to achieve target standard errors for the calibration slope. A subsequent impact analysis will compare KFRE-guided referral with current Thai CKD guideline criteria and real-world practice using a decision-tree and Markov modelling framework.
Ethics and Dissemination: Ethical approval was obtained from the Ethics Committee of the Institute for the Development of Human Research Protections, Thailand (COA No. IHRP2025110), Imperial College London, and the London School of Hygiene and Tropical Medicine. The requirement for informed consent was waived due to the use of anonymised secondary data. Findings will be disseminated through peer-reviewed publications, conferences, and policy briefs to supplement evidence-based referral strategies and health system planning.
Methods and Analysis: We will conduct a retrospective cohort study using linked, de-identified national health databases covering approximately 70% of the Thai population. Adult patients with CKD stages 3–5 will be included. KFRE performance will be evaluated at 2 and 5 years for discrimination and calibration. If miscalibration is identified, the model will be recalibrated using Cox-based methods. Simulations (1,000 iterations) indicated that approximately 920 kidney failure events by 5 years would be required to achieve target standard errors for the calibration slope. A subsequent impact analysis will compare KFRE-guided referral with current Thai CKD guideline criteria and real-world practice using a decision-tree and Markov modelling framework.
Ethics and Dissemination: Ethical approval was obtained from the Ethics Committee of the Institute for the Development of Human Research Protections, Thailand (COA No. IHRP2025110), Imperial College London, and the London School of Hygiene and Tropical Medicine. The requirement for informed consent was waived due to the use of anonymised secondary data. Findings will be disseminated through peer-reviewed publications, conferences, and policy briefs to supplement evidence-based referral strategies and health system planning.
Date Issued
2026-05-01
Date Acceptance
2026-04-28
Citation
BMJ Open, 2026, 16 (5)
ISSN
2044-6055
Publisher
BMJ Publishing Group
Journal / Book Title
BMJ Open
Volume
16
Issue
5
Copyright Statement
© Author(s) (or their employer(s)) 2026. Re-use permitted under CC BY. Published by BMJ Group. https://creativecommons.org/licenses/by/4.0/This is an open access article distributed in accordance with the Creative Commons Attribution 4.0 Unported (CC BY 4.0) license, which permits others to copy, redistribute, remix, transform and build upon this work for any purpose, provided the original work is properly cited, a link to the licence is given, and indication of whether changes were made. See: https://creativecommons.org/licenses/by/4.0/.
License URL
Identifier
10.1136/bmjopen-2025-114382
Publication Status
Published
Article Number
ARTN e114382
Date Publish Online
2026-05-15