Comparison of severity predictive rules for hospitalised nursing home-acquired pneumonia in Korea: a retrospective observational study

BACKGROUND: Nursing home-acquired pneumonia (NHAP) is the leading cause of death among long-term care residents. AIMS: To compare current scoring indices (NHAP model score, Pneumonia Severity Index (PSI), CURB-65 (confusion, urea nitrogen, respiratory rate, blood pressure, age >65 years) and SOAR (systolic blood pressure, oxygenation, age, respiratory rate)) in predicting mortality and admission to the intensive care unit (ICU) in patients with NHAP. METHODS: This retrospective observational study was conducted between July 2008 and June 2011 using data from the Korean Nursing Home Networks. Two hundred and eight nursing home residents were hospitalised with pneumonia in one general hospital. The primary outcome measure was 30-day all-cause mortality. Secondary outcome measures were intensive respiratory or vasopressor support (IRVS), and severe pneumonia (ICU admission or IRVS). RESULTS: PSI class V showed the highest Youden index (0.45), specificity (66.7%), positive predictive value (PPV, 40.0%), negative predictive value (NPV, 91.5%), and area under the curve (AUC, 0.73) for 30-day mortality. For severe pneumonia, PSI class V showed the highest Youden index (0.40), specificity (72.8%), PPV (62.2%), NPV (77.1%), and AUC (0.70). Similarly, PSI class V showed the highest Youden index (0.35), specificity (68.3%), PPV (51.1%), NPV (80.5%), and AUC (0.69) for IRVS. CONCLUSIONS: The PSI has superior discriminatory power in predicting all three clinical outcomes (30-day mortality, severe pneumonia, and IVRS) compared with the NHAP model score, CURB-65 and SOAR.