Comprehensive analysis of prognostic factors in hospitalized patients with pneumonia occurring outside hospital: Serum albumin is not less important than pneumonia severity assessment scale.

PURPOSE: This study aimed to elucidate factors related to 30-day mortality of pneumonia occurring outside hospital by comprehensively analyzing data considered relevant to prognosis.

METHODS: Data considered relevant to prognosis were retrospectively examined from clinical charts and chest X-ray images of all patients with pneumonia occurring outside hospital admitted to our hospital from 2010 to 2016. The primary outcome was 30-day mortality.

RESULTS: Data were collected from 534 patients (317 community-acquired pneumonia and 217 nursing- and healthcare associated pneumonia patients; 338 men (63.3%); mean age, 76.2 years-old). Eighty-three patients (9.9%) died from pneumonia within 30 days from the date of admission. The numbers of patients with pneumonia severity index (PSI) classes of I/II/III/IV/V and age, dehydration, respiratory failure, orientation disturbance, pressure (A-DROP) scores of 0/1/2/3/4/5 were 29/66/127/229/83, and 71/107/187/132/30/7, respectively. Mean (standard deviation) body mass index (BMI), serum albumin, blood procalcitonin, white blood cell and C-reactive protein were 20.00 (4.12) kg/m2 , 3.16 (0.60) g/dL, 3.69 (13.15) ng/mL, 11559.4 (5656.9)/mm3 , and 10.92 (8.75) mg/dL, respectively. Chest X-ray images from 152 patients exhibited a pneumonia shadow over a quarter of total lung field. Logistic regression analysis revealed that PSI class or A-DROP score, BMI, serum albumin, and extent of pneumonia shadow were related to 30-day mortality. Receiver operating characteristics curve analysis revealed that serum albumin was superior to PSI class or A-DROP score for predicting 30-day mortality.

CONCLUSION: Serum albumin is not less important than PSI class or A-DROP score for predicting 30-day mortality in hospitalized patients with pneumonia occurring outside hospital.