Risk Factors for the Persistence of Respiratory Symptoms in Childhood Asthma

Abstract

We studied the prognosis of childhood asthma in a cohort of 406 children 8 to 12 yr of age when enrolled. Subjects were followed for a mean of 14.8 yr after their initial evaluation, with a follow-up rate of 86%. The mean age at follow-up was 24.7 yr. We assessed the predictive value of sex and various childhood variables on the outcome of symptoms and medication use in adulthood. Although only 19% of subjects were still under a physician's supervision at the time of follow-up, 76% had respiratory symptoms, 32% used maintenance medication, and 22% used medication intermittently. The incidence of cigarette smoking was disturbingly high (33%). In adulthood, women were more likely than men to have symptoms (85 versus 72%, respectively). The childhood symptom severity and the childhood degree of bronchial responsiveness in combination with a low %FEV1 were also related to the outcome of asthma in adulthood. The high prevalence of symptoms in adults at follow-up coupled with the low rate of physician supervision and medication usage suggest that more aggressive treatment may be indicated in asthmatic children.

Incidence and Remission of Asthma in Schoolchildren: Report From the Obstructive Lung Disease in Northern Sweden Studies

“…The high remission rate is in accordance with other studies, which have shown that ϳ50% of childhood asthma may remit. 26,27 Among teenagers a remission rate of 5.7% per year has been reported, 24 whereas in a follow-up study from 8 to 25 years of age, 24% became free from respiratory symptoms. 27 In another follow-up study from 15 to 23 years of age, 16% of the participants were free from asthma medicines and wheezing.…”

Asthma: from childhood to adulthood

“…Seven of these studies did not find a are asymptomatic subjects who have bronchial difference in outcome (1,28,47,50,(58)(59)(60), another responsiveness, but do not perceive induced bronone found women to have a better prognosis than chial obstruction during histamine provocation men (41), and two found female sex to be associ- (64). The same is true of asthmatic subjects, some ated with a poor outcome (32,55). reporting little discomfort with severe airway In the Melbourne study, which started in 1964, obstruction, whereas others experience marked 401 children were randomly selected from 30 000 (55) could not support this hypothesis.…”

“…Most follow-up studies from childhood to adulthood have shown that roughly 50% of children do "outgrow" their asthma (18, 41,47,55,56). One aspect related to outcome is age at onset of respiratory symptoms.…”

“…Other investigators, however, found no effect of age at onset of wheeze on the outcome of asthma (32,47,54), or even an association with a positive outcome (38,49,61). One reason for these contradictions is that most of the follow-up studies recruited their subjects at the age of 7 years or older (28,39,45,47,55,56,59) and are therefore susceptible to "recall bias", even if they were prospective in nature. By the time the children were 7 years old, some parents might have forgotten minor episodes of wheeze; therefore, studies may have underestimated the percentage of children with an early onset of wheezing who continued to wheeze as adults.…”

“…Research into a link between eczema as a risk factor for the progression of asthma is complicated by the fact that eczema is generally defined as imprecisely as asthma itself. A further problem is that many studies did not include a physical examination to establish the presence of eczema, but based their findings on questionnaires only (28,32,41,47,55). Because eczema is a disease that changes in severity within hours or days, it is difficult to determine its role in the persistence and severity of asthma.…”