Risk factors for asthma incidence. A review of recent prospective evidence.
OBJECTIVE
The aim of this study is to determine what factors have been shown, in prospective studies, to predict the incidence of asthma.


METHODS
We performed a systematic review of peer-reviewed literature from 1994 to 2004 to determine what factors predict the development of asthma in both children and adults. This search strategy yielded 40 studies, with 36 providing some estimate of asthma incidence for the total sample and or a specific subgroup.


RESULTS
Annual estimated incidence of physician-diagnosed asthma ranged from 0.6 to 29.5 per 1000 persons. Risk factors for incident asthma among children included: male sex, atopic sensitization, parental history of asthma, early-life stressors and infections, obesity, and exposure to indoor allergens, tobacco smoke and outdoor pollutants. Risk factors for adult-onset asthma included female sex, airway hyperresponsiveness, lifestyle factors, and work-related exposures.


CONCLUSIONS
Risk factors for asthma include both modifiable and nonmodifiable ones, and they vary between children and adults. This review of prospective evidence supports tobacco and smoke avoidance as an intervention for the primary prevention of childhood asthma. During adolescence and adulthood, targeting lifestyle factors like obesity and smoking or reducing occupational exposures are the best opportunities for asthma prevention. Before specific public health recommendations can be made, however, additional longitudinal research is needed to better characterize target populations and identify appropriate settings for multifaceted asthma interventions.
King
M E
ME
Air Pollution and Respiratory Health Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA. Mking2@cdc.gov
Mannino
D M
DM
Holguin
F
F
D001249:Asthma / Q000453:epidemiology* / Q000209:etiology*; D006801:Humans; D015994:Incidence; D009765:Obesity / Q000150:complications; D011446:Prospective Studies; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects; D014481:United States / Q000453:epidemiology