Regarding the availability of 28-day mortality in MIMIC-IV V2.0

Prerequisites

• Put an X between the brackets on this line if you have done all of the following:
  • Checked the online documentation: https://mimic.mit.edu/
  • Checked that your issue isn't already addressed: https://github.com/MIT-LCP/mimic-code/issues/1199

Description

MIMIC-IV V2.0 was released on June 12, 2022. The date of death is available within the 'dod' column of the 'patients' table since V2.0, and the maximum follow-up time for each patient is exactly one year after their last hospital discharge. With out-of-hospital follow-up mortality(stop getting death from Social Security Death Index, but purchasing the data from the CDC), MIMIC-IV V2.0 provides a basis for calculating 28-day mortality(same as 30-day, 60-day, 90-day, and even up to 1-year mortality, etc.). Some scholars have used 28-day mortality as clinical outcome in their studies with MIMIC-IV V2.0.

Zhu, Z., Zhou, M., Wei, Y. et al. Time-varying intensity of oxygen exposure is associated with mortality in critically ill patients with mechanical ventilation. Crit Care 26, 239 (2022). https://doi.org/10.1186/s13054-022-04114-w

However, I noticed that the source of out-of-hospital mortality was from 'state records’, and I‘m confused with the data source(I'm an ICU physician in China mainland, I am not familiar with the US government institutions), I mean whether the data was from the state CDC(Massachusetts) or the national CDC？

If the survival data come from the CDC of Massachusetts, for after discharge of Non-Massachusetts patients(who come from other states and even from other countries), their follow-up information can be tracked and recorded by the CDC of Massachusetts? I know the vast majority of patients in MIMIC-IV should be local residents, and only a very small percentage of patients may fall into the category I mentioned above. If out-of-hospital survival data for non-Massachusetts patients could not be tracked, could I exclude this part of non-Massachusetts patients based on certain fields(for example, insurance from admissions or other fields)?

As it's important for the clinical outcome of our project, I am interested in whether metrics such as 28-day mortality can be used in MIMIC-IV V2.0. In other words, I would like to ask whether the state(Massachusetts?) CDC data cover the vast majority of patients for out-of-hospital survival information enough. If there are only a few are not covered, the impact of those few can be ignored?

In summary, 28-day mortality as the clinical outcome can be used in MIMIC-IV V2.0?

@alistairewj

Start with the MIMIC-IV 2.0 documentation and the linked issue #1199, then review the description of the patients.dod column and the stated source of out-of-hospital mortality as state records. Done means documenting whether 28-day mortality is supported and how coverage of non-Massachusetts patients should be interpreted.