Nationwide trends in pneumonia hospitalization rates and mortality, Denmark 1997-2011

Respir Med. 2014 Aug;108(8):1214-22. doi: 10.1016/j.rmed.2014.05.004. Epub 2014 May 20.


Objective: To provide up-to-date population-based data on nationwide trends in pneumonia hospitalization rates and associated 30-day mortality.

Methods: Using medical databases we identified all in-hospital episodes of pneumonia between 1997 and 2011. We computed age- and sex-standardized hospitalization rates of total and first-time pneumonia-related hospitalization and adjusted 30-day mortality rates by calendar year.

Results: Among 552,528 pneumonia-related hospitalizations in Denmark between 1997 and 2011, 385,985 (69.9%) were first-time events. Total pneumonia hospitalizations increased by 63%, from 4.96 per 1000 population in 1997 to 8.09 in 2011. Rates of first-time pneumonia per 1000 population increased by 33%, from 3.99 in 1997 to 5.31 in 2011. Pneumonia rates stabilized in the mid-00s but primary pneumonia rates increased 16% from 2008 to 2011, most notably among children and young adults. In patients aged ≥80 years the rate of hospitalizations with secondary pneumonia more than doubled during the study period. Average 30-day mortality remained stable at 13%, but increased slightly over time in patients aged ≥80 years.

Conclusions: In an era of smoking cessation and vaccination efforts, pneumonia hospitalization rates are continuously increasing, largely driven by secondary diagnoses and recurrent pneumonia episodes in elderly patients. Thirty-day mortality remains persistently high.

Keywords: Age; Comorbidity; Epidemiology; Incidence; Outcome; Pneumonia.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Age Distribution
  • Aged
  • Aged, 80 and over
  • Child
  • Child, Preschool
  • Cohort Studies
  • Denmark / epidemiology
  • Female
  • Hospitalization / statistics & numerical data
  • Hospitalization / trends*
  • Humans
  • Infant
  • Infant, Newborn
  • Male
  • Middle Aged
  • Pneumonia / mortality*
  • Sex Distribution
  • Young Adult