Performance of severity scores for home care-based patients suffering from pneumonia

The Pneumonia Severity Index (PSI) is used to determine the prognosis of community-acquired pneumonia (CAP). The concept of nursing- and healthcare-associated pneumonia (NHCAP) has recently been established in Japan. The present study aims to examine whether the PSI can predict the prognosis of home care-based patients diagnosed with NHCAP.

We retrospectively sampled 97 home care-based patients diagnosed with pneumonia in 2011 at Aozora Clinic in Kamihongo. Each case was scored using the PSI, the A-DROP and the CURB-65, and the severity of each case was evaluated. We also modified the PSI to obtain the score on the site of the home visits by omitting the scores related to the radiographic and laboratory findings. We call this new score the modified PSI for home care-based patients (PSI-HC). We assessed how well each score predicted mortality.

The correlation efficiency of the PSI and the PSI-HC before categorization was 0.89. All the four scores well predicted the mortality, with the area under the curve of the receiver operating characteristic curves of the PSI, the PSI-HC, the A-DROP and the CURB-65 being 0.859, 0.856, 0.778, and 0.806, respectively. These scores also predicted the hospitalization rate, but more than two-thirds of high-scoring patients received therapy at home contrary to the recommendations of guidelines.

All four scores for CAP well predicted the prognosis of pneumonia of the home care-based patients, which was categorized in NHCAP. The decision of hospitalization was made not only by considering the severity of the pneumonia.