Epidemiology of Symptom Perception in Childhood Asthma

BACKGROUND:

The treatment of childhood asthma increasingly entails self-management as an important factor in influencing the course of the disease. The study identified subgroups of children who were at increased risk of misinterpreting, and thus mismanaging, their pulmonary function. Identification of the characteristics of these high risk children formed the basis for subsequent development of an intervention program to improve symptom self-perception, thereby enhancing the children's ability to participate effectively in self-management of their asthma.

DESIGN NARRATIVE:

The specific hypotheses tested in the cross-sectional prevalence study were: 1) greater validity of self-perceived symptoms was associated with less functional morbidity from asthma; 2) specific psychological and asthma-related determinants affected the sensitivity and specificity of symptom perception in children with asthma; 3) perception of respiratory symptoms was a measurable characteristic that could be evaluated in terms of reliability and validity; 4) perceptual accuracy in a natural or clinical setting was significantly related to perceptual ability measured in a laboratory.

Investigation of these objectives used a study of validity of self-perception of symptoms in relation to clinical status. Children aged 8-15 made subjective estimates of their asthma severity immediately prior to pulmonary function testing at multiple times while they lived either at a summer camp for children with asthma or a long-term asthma treatment center. The correspondence between subjective and objective measures of pulmonary function in the clinical environment were compared with results obtained in a laboratory using threshold detection of added resistive loads. The sensitivity and specificity of asthmatic children's self-assessment of symptom state were quantified and related retrospectively to risk of functional morbidity. Cognitive abilities, anxiety level, tendency toward repression, locus of control, and familial factors were investigated regarding their role as determinants of sensitivity and specificity of symptom self-perception as a measure of pulmonary function. The stability of individual patterns of self-perception were studied longitudinally with annual repeated evaluations among those children who returned to camp or were rehospitalized.