Clinical Characteristics of Influenza-Associated Pneumonia of Adults: Clinical Features and Factors Contributing to Severity and Mortality.

: Pneumonia is a major complication of influenza that contributes to mortality. Clinical characteristics and factors of influenza virus contributing to the severity and mortality of pneumonia have not been fully elucidated. : The objective was to clarify clinical characteristics and factors contributing to the severity and mortality of influenza-associated pneumonia (). : We retrospectively analyzed patients with . : From December 1999 to March 2016, 210 patients with a median age of 69 (range, 17 to 92) years with based on positive rapid antigen tests, increased antibody titers of paired sera, or positive results of reverse transcription polymerase chain reaction were admitted to our institution. A multivariate analysis found that advanced age (≥ 65 years), pneumonia subtypes (unclassified), diabetes mellitus, and acute kidney injury complicated with were independent factors associated with disease severity, whereas pneumonia subtypes (mixed viral and bacterial pneumonia and unclassified), healthcare-associated pneumonia, acute kidney injury complicated with , and severity on admission (severe) were independent factors associated with non-survival. : The clinical characteristics of are varied, and the contribution of several factors to the severity and mortality of suggest their importance in either preventing or managing after it develops.