N W Johnston

..Predictable peaks of asthma exacerbation requiring hospital treatment, of greatest magnitude in children and of uncertain etiology, occur globally after school returns...

..A recurring epidemic of asthma exacerbations in children occurs annually in September in North America when school resumes after summer vacation...

..Mixture models are employed for regression analysis of zero-inflated data. Moreover, for repeated measures zero-inflated data the clustering structure should also be modeled for an adequate analysis...

..Viral infections are associated with the majority of asthma exacerbations in children and adults. Increased asthma hospitalization rates of children and adults, particularly in the early fall, have been observed to follow school vacations...

..Epidemiologically, the degree of asthma control achieved by asthmatics is an important predictor of the likelihood of disease exacerbation including respiratory failure, death, and health service consumption...

..The differences between age and disease exacerbation patterns after school return and at Christmas suggest that either different agents are involved or that the response to a common agent is different between the two signal events...

..Low use of asthma medications during summer may fuel the epidemic, which may be attenuated by the short-term addition of an effective controller therapy...