This calculator is for general information and education. It is not medical advice and does not replace the judgment of a doctor, nurse or pharmacist who knows the full clinical picture.
Around one in seven patients discharged from a medical ward comes back to hospital within a month. The LACE index, developed by van Walraven and colleagues in Ontario in 2010, is a quick way to find the patients at highest risk of dying or being readmitted within 30 days of discharge, so that follow-up calls, early clinic visits and home care can be targeted.
The letters
| Letter | Item | Points |
|---|---|---|
| L | Length of stay | under 1 day 0, 1 day 1, 2 days 2, 3 days 3, 4 to 6 days 4, 7 to 13 days 5, 14 days or more 7 |
| A | Acute (emergent) admission | 3 |
| C | Charlson comorbidity index | 0 → 0, 1 → 1, 2 → 2, 3 → 3, 4 or more → 5 |
| E | Emergency department visits in the previous 6 months | 1 per visit, up to 4 |
The total runs from 0 to 19. The Charlson index counts conditions such as heart failure, diabetes with complications, chronic lung disease, kidney disease, cancer and dementia; our Charlson calculator works it out.
Example
A patient admitted through the emergency department (3), who stayed 5 days (4), has a Charlson index of 2 (2) and came to the emergency department once in the last six months (1), scores 10: high risk.
Interpretation
| Score | Risk |
|---|---|
| 0 to 4 | low |
| 5 to 9 | moderate |
| 10 or more | high |
In the original study, the expected risk of death or urgent readmission rose from about 2% at a score of 0 to over 40% at the top of the scale. A threshold of 10 is the cut-off used by most programs to flag high-risk patients.
How it is used
Hospitals calculate LACE at discharge, often automatically from the administrative record, and offer high scorers a phone call within 48 hours, a follow-up appointment within a week, medication review and help from community nurses.
Limits
LACE predicts all readmissions, including ones nobody could prevent. It does not capture social isolation, frailty, cognitive problems or medication adherence, which nurses and social workers should still assess. The HOSPITAL score is an alternative that focuses on potentially avoidable readmissions.