Multicenter survey on hospital-acquired pneumonia and the clinical efficacy of first-line antibiotics in Japan

Objective: The aim of this study was to investigate the pathophysiology of hospital-acquired pneumonia (HAP) and the clinical efficacy of its first-line treatment and to examine the validity of "the Japanese Respiratory Society (JRS) Guidelines for management of HAP". Methodology: The observational survey was conducted during the period of June 2002-May 2004 and patients with HAP were prospectively surveyed using the consecutive enrollment method. A total of 1,356 patients from 254 hospitals nationwide were analyzed. Clinical response to first-line antibiotics was evaluated at the end of the medication. Results: The 30-day mortality rate was 19.8%. Patients were classified into four groups according to the JRS guideline criteria. There were remarkable variances in the number of cases of each group. Mild/moderate pneumonia with no risk factors (group I) accounted for 0.3% of all cases. The mortality rate tended to be higher, as clinical conditions became more serious (group II < III < IV). Alternatively, though categorized in the same group (group III), there was a difference in the mortality rate by the severity of pneumonia (severe cases 32.2% vs. moderate cases 11.0%). First-line medication using carbapenems accounted for 61.7% of total cases. The efficacy rate of guideline-concordant therapy was significantly higher than that of guideline-discordant therapy (54.2% vs. 41.7%). Conclusions: This is the first nationwide study on HAP in Japan. The clinical characteristics and prognosis of HAP were elucidated. Review of the current classification of the disease is required and these results provide valuable information for the next revision of the guidelines.