Identification and prediction of patients who are at risk of hospital 
readmission is a critical step towards the reduction of the potential avoidable 
costs for healthcare organisations. This research was focused on the evaluation 
of LACE Index for Readmission - Length of stay (days), Acute (emergent) 
admission, Charlson Comorbidity Index and number of ED visits within six months 
(LACE) and Patients At Risk of Hospital Readmission (PARR) using New Zealand 
hospital admissions. This research estimates the risk for all readmissions 
rather than only those in a subset of referenced conditions. In total, 213,440 
admissions between 1 Jan 2015 and 31 Dec 2016 were selected after appropriate 
ethics approvals and permissions from the three hospitals. The evaluation method 
used is the Receiver Operating Characteristics (ROC) analysis to evaluate the 
accuracy of both the LACE and PARR models. As a result, The LACE index achieved 
an Area Under the Curve (AUC) score of 0.658 in predicting 30-day readmissions. 
The optimal cut-off for the LACE index is a score of 7 or more with sensitivity 
of 0.752 and specificity of 0.564. Whereas, the PARR algorithm achieved an AUC 
score of 0.628 in predicting 30-day readmissions. The optimal cut-off for the 
PARR index is a score of 0.34 or more with sensitivity of 0.714 and specificity 
of 0.542.