LACE index predicts age-specific unplanned readmissions and mortality after hospital discharge.

BACKGROUND: The LACE index scoring tool (Length of stay, Acuity of admission, Co-morbidities and Emergency department visits) has been designed to predict hospital readmissions. We evaluated the ability of the LACE index to predict age-specific frequent admissions and mortality. METHODS: Analysis of prospectively collected data of alive-discharge episodes between 01/04/2017 and 31/03/2019 in an NHS hospital. Data on 14,878 men and 17,392 women of mean age 64.0 years, SD = 20.5, range 18.0-106.7 years were analysed. The association of the LACE index with frequency of all-cause readmissions within 28 days of discharge and over a 2-year period, and with all-cause mortality within 30 days or within 6 months after discharge from hospital were evaluated. RESULTS: Within LACE index scores of 0-4, 5-9 or ≥ 10, the proportions of readmission ≥ 2 times within 28 days of discharge were 0.1, 1.3 and 9.2% (χ2 = 3070, p < 0.001) and over a 2-year period were 1.7, 4.8 and 19.1% (χ2 = 3364, p < 0.001). Compared with a LACE index score of 0-4, a score ≥ 10 increased the risk (adjusted for age, sex and frequency of admissions) of death within 6 months of discharge by 6.8-fold (5.1-9.0, p < 0.001) among all ages, and most strongly in youngest individuals (18.0-49.9 years): adjusted odds ratio = 16.1 (5.7-45.8, p < 0.001). For those aged 50-59.9, 60-69.9, 70-79.9 and ≥ 80 years, odds ratios reduced progressively to 9.6, 7.7, 5.1 and 2.3, respectively. Similar patterns were observed for the association of LACE index with mortality within 30 days of hospital discharge. CONCLUSIONS: The LACE index predicts short-term and long-term frequent admissions and short-term and medium-term mortality, most pronounced among younger individuals, after hospital discharge.

Derivation of age-adjusted LACE index thresholds in the prediction of mortality and frequent hospital readmissions in adults.

The LACE index has been shown to predict hospital readmissions and death with variable accuracy. A LACE index ≥ 10 is considered as high risk in the existing literature. We aimed to derive age-specific LACE index thresholds in the prediction of mortality and frequent readmissions. Analysis of prospectively collected data of consecutive alive-discharge episodes between 01/04/2017 and 31/03/2019 to a single hospital was conducted. The derivation of LACE index thresholds for predicting all-cause mortality within 6 months of hospital discharge or frequent readmissions (≥ 2 times within 28 days) was examined by receiver operating characteristics (ROC) in 32270 patients (14878 men, 17392 women) aged 18-107 year (mean = 64.0 years, SD = 20.5). For all patients with a LACE index ≥ 10, the area under the curve (AUC) for predicting mortality was 80.5% (95% CI 79.7-81.3) and for frequent readmissions was 84.0% (83.0-85.1). Two-graph ROC plots showed that the LACE index threshold where sensitivity equates specificity was 9.5 (95% intermediate range = 5.6-13.5) for predicting mortality and 10.3 (95% intermediate range = 6.6-13.6) for frequent readmissions. These thresholds were lowest among youngest individuals and rose progressively with age for mortality prediction: 18-49 years = 5.0, 50-59 years = 6.5, 60-69 years = 8.0, 70-79 years = 9.8 and ≥ 80 years = 11.6, and similarly for frequent readmissions: 18-49 years = 5.1, 50-59 years = 7.5, 60-69 years = 9.1, 70-79 years = 10.6 and ≥ 80 years = 12.0. Positive and negative likelihood ratios (LRs) ranged 1.5-3.3 and 0.4-0.6 for predicting mortality, and 2.5-4.4 and 0.3-0.6 for frequent readmissions, respectively, with stronger evidence in younger than in older individuals (LRs further from unity). In conclusion, the LACE index predicts mortality and frequent readmissions at lower thresholds and stronger in younger than in older individuals. Age should be taken into account when using the LACE index for identifying patients at high risk.