Clinical characteristics of extremely elderly patients with community-acquired and healthcare-associated pneumonia in Japan

Background Clinical characteristics of extremely elderly people with pneumonia have scarcely been reported. Japan is now facing rapid population aging. Objective To elucidate clinical characteristics of elderly patients with community-acquired or healthcare-associated pneumonia (CAP or HCAP). Methods The study was conducted as a sub-study of the prospective multicentre surveillance for pneumonia including 4 community hospitals in Japan (Adult Pneumonia Study-Japan), which started in September 2011. Clinical information was collected from patients and medical records using a standardised data collection form. Sputum samples were examined by conventional bacterial cultures and multiplex-PCR assays. The data collected at one of participating hospitals was used for this sub-analysis. Results From January to October 2012, 156 patients were enrolled. Among them, 53(34%) were aged ≥85 years, 54(35%) 75-84 years, and 49(31%) <75 years. The extremely elderly patients aged ≥85 years had a significantly lower heart rate, respiratory rate, and sputum culture positive rate than younger patients. Patients aged ≥75 years were more likely to have comorbidities, to be diagnosed with HCAP, and to receive prehospital care. Cough, sputum, chest pain, fever, chill/shaking and headache were less commonly seen, and hematocrit was lower, and major pathogens of pneumonia ( Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis ) were less common and gram negative bacteria were more common in this age group. Conclusions Older pneumonia patients are less likely to have major symptoms, appropriate responses in typical warning vital signs, and common causative pathogens.