General Medicine & Vital Signs

LACE Index Calculator – Hospital Readmission and Mortality Risk

Clinical calculation support · Verify results before clinical use

LACE Index Calculator

Estimate 30-day risk of death or unplanned readmission after hospital discharge.

—Score / 19

Length of Stay

Total length of the index hospital admission, in days.

0–7 points

Length of stay (days) Enter 0 for a stay shorter than 1 day. Use a whole number.

Acuity of Admission

Was the index hospital admission acute (emergent) or planned?

0–3 points

Elective / planned0 points

Acute / emergent3 points

Charlson Comorbidity Index

Enter the patient's total Charlson Comorbidity Index score, not the number of diagnoses.

0–5 points

Charlson Comorbidity Index score LACE assigns 5 points for a Charlson score of 4 or higher.

Emergency Department Visits

Number of ED visits during the 6 months before the index admission.

0–4 points

ED visits in the previous 6 months

—LACE

Estimated 30-day composite outcome risk

Complete all fields to calculate

The score and expected risk will appear here.

Clinical interpretation Complete all four components. A higher LACE score indicates a higher expected risk of death or unplanned readmission within 30 days after discharge.

The expected probabilities are from the original Canadian derivation cohort. They may not be calibrated to other healthcare systems or patient populations.

About the LACE Index

The LACE index is a prognostic score developed to estimate the risk of early death or unplanned readmission within 30 days after discharge from hospital to the community. It combines four routinely available variables: length of stay, acuity of admission, comorbidity burden, and prior emergency department use.

The total score ranges from 0 to 19. The expected probability displayed by this calculator corresponds to the original model's score-specific estimates, not a locally recalibrated prediction.

Scoring Components

Component	Patient value	Points
Length of stay	<1 day	0
	1 day	1
	2 days	2
	3 days	3
	4–6 days	4
	7–13 days	5
	≥14 days	7
Acuity	Elective / planned	0
	Acute / emergent	3
Charlson score	0 / 1 / 2 / 3 / ≥4	0 / 1 / 2 / 3 / 5
Prior ED visits	0 / 1 / 2 / 3 / ≥4	0 / 1 / 2 / 3 / 4

Expected 30-Day Risk in the Original Model

These are expected probabilities of death or unplanned readmission reported by van Walraven et al. (2010). They are not standalone readmission probabilities.

LACE score	Expected risk	LACE score	Expected risk
0	2.0%	10	12.2%
1	2.5%	11	14.4%
2	3.0%	12	17.0%
3	3.5%	13	19.8%
4	4.3%	14	23.0%
5	5.1%	15	26.6%
6	6.1%	16	30.4%
7	7.3%	17	34.6%
8	8.7%	18	39.1%
9	10.3%	19	43.7%

References

van Walraven C, Dhalla IA, Bell C, et al. Derivation and validation of an index to predict early death or unplanned readmission after discharge from hospital to the community. CMAJ. 2010;182(6):551–557. DOI: 10.1503/cmaj.091117.

Staples JA, Wiksyk B, Liu G, et al. External validation of the modified LACE+, LACE+, and LACE scores to predict readmission or death after hospital discharge. J Eval Clin Pract. 2021;27(6):1390–1397. DOI: 10.1111/jep.13579.

Rajaguru V, Han W, Kim TH, Shin J, Lee SG. LACE Index to Predict the High Risk of 30-Day Readmission: A Systematic Review and Meta-Analysis. J Pers Med. 2022;12(4):545. DOI: 10.3390/jpm12040545.

Important Limitations

The original derivation population consisted of cognitively intact adult medical or surgical patients discharged to the community.
Predictive performance may vary across populations, hospitals, and healthcare systems.
The original study reported moderate discrimination (external validation C-statistic 0.684).
The score does not identify the specific cause of a potential readmission and does not establish an individual patient's outcome.
Local validation and recalibration are needed before using the expected probabilities for operational decisions in a different population.

Clinical disclaimer: The LACE index is a prognostic risk-stratification instrument and should not be used as the sole basis for clinical decisions, discharge timing, level-of-care decisions, or allocation of services. Interpret the result alongside clinical assessment, functional status, social circumstances, discharge readiness, and local care pathways. The displayed expected probability is derived from the original study population and may not represent the actual risk in an individual patient or another healthcare setting.