Dynamic Magnesium Replacement Strategies and 28-Day Mortality in Non-Cardiac Critically Ill Patients With Hypomagnesemia: A Target Trial Emulation

This is a target trial emulation (a type of observational study that mimics a clinical trial) using data from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database (2008-2019).

Inclusion criteria

Adults (≥18 years) admitted to the ICU, with serum magnesium <1.7 mg/dL within 72 hours of admission, and no history of heart disease or cardiac surgery.

Sample size: 12,887 patients. Interventions (simulated): Three magnesium replacement strategies (Never Treat, Always Treat, Dynamic Treat).

Outcome: 28-day all-cause mortality (death from any cause). Analysis methods: We will use the G-formula (to handle time-varying factors that could affect results) and sensitivity analyses to check if findings are reliable.

Inclusion criteria

• Age ≥ 18 years.
• Admitted to the Intensive Care Unit (ICU).
• Developed hypomagnesemia (Serum Magnesium < 1.7 mg/dL) within the first 72 hours of ICU admission.

Exclusion criteria

• Admitted due to cardiac or cardiosurgical causes (e.g., Cardiac Surgery Recovery Unit, CCU, CVICU).
• Underwent cardiac surgery during hospitalization (identified by ICD-9/10 procedure codes).
• Primary discharge diagnosis of major cardiac conditions (e.g., myocardial infarction, heart failure, arrhythmias).