Pulmonary function results were not available in this cohort

The surveys used for this analysis were returned by only 20% of eligible patients. As previously reported, responders differed from nonresponders in several ways, but it is not clear whether these differences would affect the generalizability of the relationships observed in this study. Pulmonary function results were not available in this cohort, and prior studies have shown that FEV_: is independently associated with future asthma exacerbations, even after accounting for other significant demographic, environmental, allergic, and asthma severity risk factors. This study only considered patients with persistent asthma and would not apply to patients with intermittent asthma, who may also experience severe exacerbations. Finally, this study included only adults and mostly women, and generalizability of the results to children or adult males would need to be demonstrated.

In summary, we showed that asthma impairment as reflected by validated asthma control and quality-of-life instruments is significantly related to the risk of future asthma exacerbations, above and beyond a prior exacerbation history. In addition, our study shows that interference with activities is the primary subjective component of asthma impairment that is related to the risk of future exacerbations, further emphasizing the need to capture and improve this aspect of the impact of asthma on patients. These tools could be used to identify high-risk patients in clinical practice and population management. It is hoped that interventions in these high-risk patients would reduce their risk of future asthma exacerbations, but further studies will be necessary to confirm that hypothesis.

The US Food and Drug Administration (FDA) drug approval and over-the-counter drug monograph processes play an essential role in ensuring that all drugs are both safe and effective for their intended uses. Manufacturers of drugs that lack required approval have not provided the FDA with evidence demonstrating that their products are safe and effective. Some of these prescription drugs have been marketed for many years and have remained on the market despite changes to the Federal Food, Drug, and Cosmetic Act, which requires approval for safety and efficacy purposes.