3.2 Causes of hospitalization
Table 2 indicates the causes of hospitalization for all patients.
Pneumonia was the most common cause representing 55% of all cases. The
breakdown of pneumonia category was community-acquired (44.3%), nursing
and healthcare-associated (10.2%), and hospital-acquired (0.5%). The
second-most common cause (27.3%) was a poor general condition due to
the influenza infection itself. Other causes include exacerbation of
underlying chronic respiratory disease (chronic obstructive pulmonary
disease [COPD], interstitial pneumonia, bronchial asthma, and so
on), heart failure, renal failure, and miscellaneous. Rhabdomyolysis and
encephalopathy were recognized in 1.0% and 0.6%, respectively.
Thirty-nine patients (4.2%) were admitted due to social indication (the
very elderly, those living alone, or those unable to reach medical
facilities easily).