Reconcilable Differences: Asthma control
Connolly et al reported poorer asthma control based on a greater reversibility of airway disease in men in lower social classes. The only studies to assess differential pharmacologic management are two US studies done in children and adolescents, both of which concluded that asthma management may be inadequate in lower social classes. The likelihood that different factors impact asthma control in children and adults prevents the direct extrapolation of these results to adult asthmatics. Furthermore, if access to health care is an important etiologic factor, class differences in access to health care between the US and Canada may mean a lesser likelihood of a social gradient in a Canadian population. The persistence of the association in individuals in our study receiving social assistance suggests that barriers to health care are not the primary etiologic factor in poorer management, given their receipt of essentially all asthma medications and health-care services at no charge. my canadian pharmacy
Previous studies have shown that specific mutations at amino acid positions 16 and 27 render these individuals prone to P-adrenergic receptor down-regulation with persistent use of SA P-agonists. Because this would result in asthmatic patients with these genotypes being less responsive to the bronchodilatory effects of SA P-agonists, we hypothesized that asthmatics homozygous for glycine at position 16 or glutamine at position 27 would be more likely to use greater amounts of SA P-agonists. However, there was no association between excessive use of SA P-agonist and genotype at either locus, suggesting that other factors (eg, social or environmental) play a more predominant role in determining the magnitude of SA P-agonist use clinically.
By design, this sample was very heterogeneous for asthma severity, SES, and drug utilization. Although the distributions of these variables are not representative of the population distributions, this methodology facilitated the recruitment of a smaller sample size to test our hypothesis. This does raise concerns of a potential volunteer bias if uncontrolled asthmatics from either extreme of SES were more likely to participate. Evidence of differential health beliefs, health management strategies, and perceptions of ability to control one’s disease suggest that uncontrolled asthmatics of higher SES would be more likely to participate in an attempt to increase their knowledge and achieve better control, which would result in conservative estimates of all ORs. The potential for the misclassification of SES to bias the results must also be considered; however, this most commonly manifests as upward misclassifica-tion of lower social classes, which would also result in conservatively biased estimates of the magnitude of the associations.