Pre-registration v1.6: Intracranial pressure trajectory directionality and 28-day all-cause mortality (MIMIC-IV)

Pre-registration archive (frozen analysis plan) for an observational study of intracranial pressure (ICP) burden trajectory directionality and 28-day all-cause mortality in neurocritically ill adults (MIMIC-IV v3.1). Contents: the registrable pre-registration text v1.6 (Markdown + print PDF) and a README with the freeze timestamp, file checksums and the registration anchors fixed in advance. Status at archive time: no outcome association had been estimated for the exposure of interest. Outcome numbers present in the text are limited to cohort event counts and to the all-cause vs in-hospital death counts that fix the outcome definition; no coefficient, odds ratio, confidence interval, p-value or direction of effect existed, and the main analysis script did not exist. Design: retrospective cohort, pre-specified exposure (per-stay ICP slope), pre-specified outcome (28-day all-cause mortality), pre-specified model and decision rules including downgrade criteria and a deviation-logging rule. Data are not redistributed (MIMIC data use agreement).