Klemera-Doubal Biological Age (KDM) — AgeMethod data

blood-based method · published 2006 · measured from blood (routine chemistry panel; panel composition varies by implementation)

Facts

Method type	blood-based
Published	2006
Sample type	blood (routine chemistry panel; panel composition varies by implementation)
Output	Biological age (years)
Validated population	Method is a general statistical framework, not tied to one fixed population; the original paper illustrates it on a biomarker dataset, and most later implementations re-run it on NHANES data
Open or commercial	open
Formula publicly available	Yes — Klemera & Doubal 2006, Mech Ageing Dev (regression-based formula)

Required inputs

Configurable panel of clinical biomarkers (varies by implementation, commonly 7-10 NHANES-style markers)
Chronological age (years)

Original publication

Klemera P, Doubal S. A new approach to the concept and computation of biological age. Mech Ageing Dev. 2006 (volume/page range not independently confirmed beyond DOI/PMID in this pass — see note).
DOI: 10.1016/j.mad.2005.10.004 · PMID: 16318865

Limitations

Not a fixed biomarker panel — output depends on which markers the implementer chooses, so results are not directly comparable across implementations.
Original formulation predates modern omics-based clocks.
Volume/issue/page range for the original citation were not independently re-confirmed in this verification pass (DOI and PMID were); flag for a follow-up check before this citation is quoted verbatim on a page.