Epidemiology and Infection

Original Papers

Pneumonia and pneumococcus

Risk of pneumonia in relation to body mass index in Australian Aboriginal people

D. T. PHUNGa1a2 c1 and Z. WANGa1

a1 Centre for Chronic Disease, School of Medicine, University of Queensland, Queensland, Australia

a2 Centre for Environment and Population Health, Griffith University, Queensland, Australia


This study examined the relationship between body mass index (BMI) and the risk of pneumonia in Aboriginal Australians. A total of 677 adults aged 20–60 years were followed up from the baseline examination during 1992–1995 to June 2012. The pneumonia events were identified through hospital records. Pneumonia incident rates were calculated according to BMI groups. Hazard ratios were computed using Cox regression adjusting for age, smoking and alcohol consumption status. The incident rate of pneumonia was 13·3/1000 person-years, and this rate was significantly higher in females than males (hazard ratio = 1·5). Compared to males with normal BMI (18·5–24·9 kg/m2), the adjusted hazard ratio was 3·5 for males with lowest BMI (P < 0·01). Low BMI was significantly associated with a higher risk of hospitalized pneumonia for Aboriginal males. However, the U-shaped trend of this association indicates that the risk of pneumonia is likely to be associated with both low and high BMI.

(Received December 06 2012)

(Revised January 29 2013)

(Accepted February 19 2013)

(Online publication March 18 2013)

Key words

  • Aboriginal people;
  • body mass index;
  • pneumonia;
  • risk


c1 Author for correspondence: Dr D. T. Phung, 7 Angelina Street, Macgregor, Brisbane, QLD 4109, Queensland, Australia. (Email: d.phung@griffith.edu.au)