Children with asthma are more likely to have breathing problems and be hospitalized if they live with someone who smokes. This is the finding from a review of several previous studies.
The team performed what is called a meta-analysis of data from 25 studies of asthmatic children. Those studies included a total of more than 430,000 children. The review found that children with asthma who were also exposed to second-hand smoke were 66% more likely to need emergency health care and 85% more likely to be hospitalized than other children with asthma who did not spend time around smokers.
Breathing in second-hand smoke was also linked to a greater than tripled risk of having poor lung function and to a 32% higher risk of experiencing wheezing.
That exposure to tobacco smoke makes asthma symptoms worse is well known, but parents who smoke may still be doing so around their children. The new findings may be the nudge they need to get them to stop smoking.
"There is hope that smoking cessation will help improve asthma symptoms and health care utilization even after any duration or extent of second-hand tobacco exposure," said lead author Dr. Avni Joshi, an allergist and immunologist with the Mayo Clinic Children's Center in Rochester, MN. "In addition, children learn from parental behavior and they are less likely to start smoking themselves if they do not observe parental tobacco use," he said in an email interview with Reuters Health.
Most of the data used in this review came from studies conducted in more affluent countries, which means that the findings may not apply to developing countries. Researchers also lacked data on how the amount of second-hand smoke exposure affected the odds of hospitalization or complications.
The meta-analysis study was published in Annals of Allergy, Asthma and Immunology.