Days Alive and at Home at 30 Days (DAH30)

A simple, patient-centred way to measure recovery after treatment.

DAH30 is the number of days a patient is alive and at home in the first 30 days after treatment.

It combines survival, time in hospital, and recovery into a single, patient-centred outcome.

WHY DAH30 MATTERS

Most medical outcomes focus on technical success or complications.

But for patients, an important question is often:
“How quickly will I get home and recover?”

DAH30 answers this directly.

It reflects:

• Recovery after treatment
• Time spent in hospital
• Complications and readmissions
• Early survival

DAH30 aligns clinical outcomes with what matters most to patients: time at home.

DAH30 is already used in surgery and healthcare systems and is designed for real-world data and clinical registries.

HOW DAH30 IS DEFINED

Core Definition

DAH30 = Number of days alive and at home within 30 days after treatment

How it is calculated

Start with 30 days, then subtract:

• Days in hospital after treatment
• Days in rehabilitation
• Days from unplanned readmissions Death within 30 days means DAH30 = 0.

Key rules

• Day 0 is the date of treatment (days before treatment are not included)
• Patient death within 30-days means DAH30 = 0
• Unplanned re-admissions DO reduce DAH30
• Planned readmissions (e.g. staged procedures) DO NOT reduce DAH30
• Emergency department visits without admission DO NOT reduce DAH30

Simple Formula

DAH30 = 30 − (hospital days + rehab days + unplanned readmission days)

SIMPLE EXAMPLES

Example 1 (Straightforward recovery)

• Hospital stay: 2 days
• No readmissions
• DAH30 = 28 days

Example 2 (Complication + readmission)

• Hospital stay: 5 days
• Readmission: 5 days
• DAH30 = 20 days

Example 3 (Planned second procedure)

• Hospital stay: 2 days
• Planned readmission later
• DAH30 = 28 days (planned care does not reduce DAH30)

QUICK START (FOR RESEARCHERS)

Use the following formatted excel sheet and practice running through this rmarkdown document.
minimum_dataset.xlsx
workbook_minimum.Rmd

The code should create the following output file in your working directory with calculated DAH30 scores.
30days.xlsx

If the above steps work for you, you can try editing the minimum_dataset to include your own data with the same formatting.
For interrogatability, the output 30days.xlsx will show you which date intervals have been subtracted from the 30 post-op days under the column “merged_intervals”, as well as counts for those days under “overlap_days”.

WHAT OUR RESEARCH SHOWS

DAH30 has been evaluated in 614 unruptured brain aneurysm treatments at a major neurovascular centre in Melbourne (Monash Health).

• The typical patient spent 27 out of 30 days at home after treatment
• Most patients were discharged home quickly and remained at home
• Patients undergoing endovascular treatment spent more time at home than those undergoing surgery, reflecting the less invasive nature and faster recovery
• Longer or more complex procedures were associated with slower recovery
• Patient factors such as frailty and overall health also influenced time at home

Overall, DAH30 provides a simple and reliable way to measure real-world recovery after unruptured brain aneurysm treatment.

REFERENCE

Chandra RV, Taylor F, Gall S, et al.
30-day home time as a patient-centered outcome after treatment of unruptured intracranial aneurysms
J NeuroInterventional Surgery, 2026
https://doi.org/10.1136/jnis-2025-024914

WHY THIS METRIC IS USEFUL

For patients

• Clear understanding of recovery
• Helps guide expectations

For clinicians

• Simple and objective
• Reflects real recovery, not just technical success

For researchers and systems

• Can be calculated from administrative data
• Suitable for registries and large datasets
• Reduces bias compared to patient-reported outcomes 

COLLABORATION