Age- and Sex-Specific TMS Reference Intervals (Kazakhstan): code and de-identified data

Reproducible analysis pipeline (Python 3.11+, R 4.6.1) and de-identified, aggregate results for an indirect (data-mining) study establishing age- and sex-specific reference intervals for amino acids and acylcarnitines measured by FIA-MS/MS from dried blood spots in a Kazakhstani paediatric population (data freeze 2026-07-20). Contents: code/ (extraction, cohort building, CLSI EP28-A3c reference intervals with bootstrap CIs, canonical refineR cross-validation, figure/table generation); data_derived/ (per-stratum reference intervals, cohort-flow counts, inter-site Kruskal–Wallis, sex analysis) and figures/. Only de-identified aggregate statistics are included; raw individual-level records and database credentials are withheld.