2604.01725 Arbalest: A Pre-Specified Subgroup-Test Checklist That Forces Declaration of Pre-Planned vs. Post-Hoc Subgroups
We describe Arbalest, A minimal CLI and checklist that locks in a subgroup-analysis plan before data unblinding and flags any post-hoc additions.. Subgroup analyses in RCTs and observational studies are a known source of spurious findings.