Latest News - Part 5
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. Continue reading this post…
Reconcilable Differences: Discussion
Although there was no association between age, gender, or genotype and SA P-agonist use, we identified a strong and significant association between SES and the amount of SA P-agonist medications used by asthmatics, independent of asthma severity. This association was consistent across all proximate and contextual measures of SES, with gradients identified in the expected directions. This study provides the first evidence suggesting that poorer outcomes in lower SES asthmatics may not be associated solely with greater asthma severity as previously postulated, but rather also to poorer asthma control, despite universal access to health care. Continue reading this post…
Reconcilable Differences: SA
Both annual household income and level of education completed were negatively and significantly associated with the magnitude of SA (3-agonist used, with a consistent gradient across social classes (Fig 2). Adjustment for family size based on the lowincome cutoff did not affect the results. Although the gradient based on education was consistent and the overall associations were significant (p 4 canisters of SA P-agonist in the previous year, and approximately a 35% reduction in the OR for having used > 12 canisters. Continue reading this post…
Reconcilable Differences: CLDSI
This sample was well distributed across all levels of asthma severity (Table 2). All three severity scores were normally distributed across the entire range of the score, with the Ng Score encompassing its entire range, while the CLDSI and ASS ranged from 5 and 6 to 28, respectively. Table 2 also illustrates the construct validity of each severity score. According to the Canadian Asthma Guidelines, patients with moderate and severe asthma were significantly more likely to have used a greater amounts of SA P-agonists, whereas those with higher asthma severity scores (ie, less severe disease) were less likely to have used greater amounts of SA P-agonist. Furthermore, as postulated, having visited an emergency department or been hospitalized were also positively associated with SA P-agonist use, and the better one’s pulmonary function, the less likely they were to use greater amounts of SA P-agonist.
There was no significant association between age, gender, or genotype and the amount of a SA P-agonist used. Corticosteroid use, all indexes and dimensions of asthma severity, except having been hospitalized for asthma in the previous year, and all proximate and contextual measures of SES were significantly associated with SA P-agonist use. Continue reading this post…
Reconcilable Differences: Results
The proportional odds assumption was tested for each model using a Score test. If the hypothesis of proportional odds was rejected (p 4 canisters, or 12 canisters) are reported for each association. Continue reading this post…
Reconcilable Differences: Statistical Analysis
Three interval score measures of asthma severity, each based on different dimensions of asthma severity, were also used. The asthma symptom sum (ASS) is a summed score of patient-rated severity of wheeze, shortness of breath, cough, and chest tight-ness. The chronic lung disease severity index (CLDSI) is a validated summed score proposed for use in asthma, emphysema, and chronic bronchitis derived from the frequency ofshortness of breath, wheeze, cough, and sputum production. Each component of the ASS and CLDSI is included in the AQLQ(S). Therefore, these scores were derived from the corresponding AQLQ(S) questions, resulting in final severity scores ranging from 4 to 28, with higher scores representing less severe disease.
Ng proposed a score (referred to as the Ng Score) ranging from 3 (least severe) to 10 based on the frequency of daytime and nocturnal symptoms, and the percentage of predicted FEV1. Final scores were reverse coded to correspond with the direction of the ASS and CLDSI. Continue reading this post…
Reconcilable Differences: Asthma Severity
Both individual (proximate) and population (contextual) measures of SES were used. Proximate measures were based on self-reported annual household income ($20,000, $20,000 to $50,000, and >$50,000, expressed in Canadian dollars), education (years of postsecondary education and highest level completed), and the receipt of social assistance. Exploratory analysis accounting for family size based on the low-income cutoff was also performed. Contextual socioeconomic factors, ie, neighborhood median household income, unemployment rate, and the proportion of residents having received a bachelor’s degree, were derived from the linkage of the postal code of each subject’s current residence with the 1996 BC census data.
Blood was collected from each subject for DNA extraction from leukocytes. Genotyping for P2-adrenergic receptor polymorphisms at positions 16 and 27 was done using polymerase chain reaction amplification of the region containing the two polymorphisms followed by restriction endonuclease digestion. The associations between genotype and the amount of SA P-agonist used were compared separately for each locus. Homozygotes for arginine and glycine at position 16 and glutamine at position 27 were compared separately to all other individuals. Continue reading this post…