Risk factors for community-acquired pneumonia in pre-school-aged children.

Aim: To identify risk factors for children developing and being hospitalised with community-acquired pneumonia.

Methods: Children <5 years old residing in urban Auckland, New Zealand were enrolled from 2002 to 2004. To assess the risk of developing pneumonia, children hospitalised with pneumonia (n= 289) plus children with pneumonia discharged from the Emergency Department (n= 139) were compared with a random community sample of children without pneumonia (n= 351). To assess risk of hospitalisation, children hospitalised with pneumonia were compared with the children discharged from the Emergency Department. Adjusted odds ratio (OR) with 95% confidence intervals (CIs) were used to estimate the risk of pneumonia and hospitalisation with pneumonia.

Results: After adjustment for season, age and ethnicity there was an increased risk of pneumonia associated with lower weight for height (OR 1.28, 95% CI 1.10-1.51), spending less time outside (1.96, 1.11-3.47), previous chest infections (2.31, 1.55-3.43) and mould in the child's bedroom (1.93, 1.24-3.02). There was an increased risk of pneumonia hospitalisation associated with maternal history of pneumonia (4.03, 1.25-16.18), living in a more crowded household (2.87, 1.33-6.41) and one with cigarette smokers (1.99, 1.05-3.81), and mould in the child's bedroom (2.39, 1.25-4.72).

Conclusions: Lower quality living environments increase the risk of pneumonia and hospitalisation with pneumonia in New Zealand. Poorer nutritional status may also increase the risk of pneumonia. Improving housing quality, decreased cigarette smoke exposure and early childhood nutrition may reduce pneumonia disease burden in New Zealand.