| sthma treatment is challenging in older adults. To date, there is no evidence from research with older adults to support choosing the most appropriate add-on treatment for inadequately controlled asthma, despite using inhaled corticosteroids (ICS). We retrospectively investigated the comparative effectiveness, cardiovascular (CV) safety and costs associated with ICS + leukotriene receptor antagonists (ICS+LTRA) versus ICS + long acting beta agonists (ICS+LABA) treatments. We included asthmatic Medicare beneficiaries aged 66 and older, who continuously enrolled in Fee for Service Medicare with Part D coverage, and treated with ICS+LABA or ICS+LTRA in an exclusive manner.;This dissertation work was organized into two major studies. Firstly, effectiveness and CV safety outcomes were compared between the two treatments. The augmented inverse propensity weighted estimator was used to determine the effect of LABA vs. LTRA add-on therapy on asthma exacerbations requiring inpatient, emergency, or outpatient care as well as CV events, adjusting for several co-variables. Our results showed that LTRA add-on treatment was associated with increased odds of asthma-related hospitalizations/emergency department visits (OR=1.4, p<0.001), and outpatient exacerbations requiring oral corticosteroids or antibiotics (OR=1.41, p<0.001) compared to LABA treatment. LTRA add-on therapy also showed lower effectiveness in controlling symptoms as indicated by greater utilization of short-acting beta agonists (RR=1.58, p<0.001). On the other hand, LTRA add-on treatment was associated with lower odds of experiencing a CV event compared to LABA (OR=0.86, p=0.006).;Secondly, multivariable regression models with nonparametric bootstrapped standard errors were employed to compare all-cause and asthma-related costs between the two treatment groups. The results showed that ICS+LTRA treatment was associated with increased asthmarelated costs compared to ICS+LABA. With a mean of 1.06 person-years follow up, adjusted asthma-related costs were... |
