Ecologic analysis of asthma-related events and dispensing of inhaled corticosteroid- and salmeterol-containing products

Trends in international asthma mortality: analysis of data from the WHO Mortality Database from 46 countries (1993-2012)

BACKGROUND

International time trends in asthma mortality have been strongly affected by changes in management and in particular drug treatments. However, little is known about how asthma mortality has changed over the past decade. In this study, we assessed these international trends.

METHODS

We collated age-standardised country-specific asthma mortality rates in the 5-34 year age group from the online WHO Mortality Database for 46 countries. To be included in the analysis, we specified that a country must have 10 years of complete data in the WHO Mortality Database between 1993 and 2012. In the absence of consistent and accurate asthma prevalence and prescribing data, we chose to use a locally weighted scatter plot smoother (LOESS) curve, weighted by the individual country population in the 5-34-year age group to show the global trends in asthma mortality rates with time.

FINDINGS

Of the 46 countries included in the analysis of asthma mortality, 36 were high-income countries, and 10 were middle-income countries. The LOESS estimate of the global asthma mortality rate was 0·44 deaths per 100 000 people (90% CI 0·39-0·48) in 1993 and 0·19 deaths per 100 000 people (0·18-0·21) in 2006. Despite apparent further reductions in some countries and regions of the world, there was no appreciable change in global asthma mortality rates from 2006 through to 2012, when the LOESS estimate was also 0·19 deaths per 100 000 people (0·16-0·21).

INTERPRETATION

The trend for reduction in global asthma mortality observed since the late 1980s might have stalled, with no appreciable difference in a smoothed LOESS curve of asthma mortality from 2006 to 2012. Although better implementation of established management strategies that have been shown to reduce mortality risk is needed, to achieve a further substantive reduction in global asthma mortality novel strategies will also be required.

FUNDING

The Medical Research Institute of New Zealand, which is supported by Health Research Council of New Zealand Independent Research Organisation.

Pharmacoepidemiological Study of Long-Acting β-agonist/Inhaled Corticosteroid Therapy and Asthma Mortality: Clinical Implications

RATIONALE

The increased risk of asthma mortality in association with long-acting β₂-agonist (LABA) monotherapy is well documented but the risk associated with LABA plus inhaled corticosteroid (ICS) therapy remains unclear.

OBJECTIVE

We assessed the feasibility of a large pharmacoepidemiological study to compare the effect of combined LABA + ICS therapy with non-LABA maintenance therapy on the risk of asthma mortality.

METHODS

This observational retrospective study used electronic data from ten US data partners to construct a cohort of patients with persistent asthma (defined as: four or more asthma maintenance medication dispensings in 12 months and a code diagnosis of asthma). Asthma deaths were determined by linking patient data with the National Death Index.

RESULTS

From 5,881,438 asthma patients, a cohort of 994,627 met the criteria for persistent asthma and provided 2.4 million person-years of follow-up. The total number of deaths was 278 with only three of these occurring after incident exposure to an asthma maintenance medication. The overall pooled asthma mortality rate, standardized by age and data partner, was 1.16 [95 % confidence interval (CI) 0.98-1.34] per 10,000 person-years; crude mortality rates (per 10,000 person-years) increased with age and were higher in female individuals (1.34; 95 % CI 1.15-1.55) than in male individuals (0.92; 95 % CI 0.74-1.12).

CONCLUSIONS

Despite a cohort size of almost 1 million asthma patients, the asthma mortality risk associated with combined LABA + ICS therapy could not be determined. This study showed that very few patients with persistent asthma have asthma-related deaths, and confirmed that those who die are more likely to be older and female.

Are inhaled longacting β2 agonists detrimental to asthma?

Possible adverse effects of adrenergic bronchodilators in asthma have been the subject of discussion for more than half a century, with recent intense debate about the safety of longacting β agonists (LABAs). In this Debate, we consider the issues of bronchodilator and bronchoprotective tolerance resulting from the frequent use of bronchodilators, which is noted particularly with shortacting drugs, but has also been shown to occur quicker and to a greater extent with LABAs. Increased allergen responsiveness and masking allowing inflammation to increase, while symptoms and lung function remain apparently controlled, have also been observed. Studies in which LABAs were used as monotherapy were associated with increased mortality. However, several studies have shown the benefits of adding LABAs to inhaled corticosteroids (ICS). Meta-analyses of asthma clinical trials involving LABAs showed that, when given with mandatory ICS, LABAs were not associated with an increased risk of death, intubations, or hospital admission for exacerbations when compared with use of the same dose of ICS only. Withdrawal of LABA therapy once symptom control is achieved is often associated with subsequent loss of symptom control. When used for appropriate indications, LABAs should be combined with ICS in one inhaler so that monotherapy is not possible.

An update on the safety of long-acting beta-agonists in asthma patients using inhaled corticosteroids

IMPORTANCE OF THE FIELD

Pooled trial data have shown that long-acting beta-agonists increase the risk for asthma hospitalizations and deaths by two to fourfold compared with placebo. Until recently, it was unclear whether concomitant inhaled corticosteroids (ICSs) could eliminate this risk.

AREAS COVERED IN THIS REVIEW

This review summarizes the available data on the safety of long-acting beta-agonist use in asthma, with and without concomitant ICSs. The results from an updated meta-analysis are presented, with data through December 2008.

WHAT THE READER WILL GAIN

In pooled trial data, catastrophic asthma events (defined as asthma-related intubation or death) were increased fourfold for concomitant treatment with long-acting beta-agonists and ICSs compared with corticosteroids alone (odds ratio 3.7; 95% CI 1.4 - 9.6). It is estimated that the addition of long-acting beta-agonists to ICS therapy is associated with an absolute increase of one catastrophic event per 1500 patient-years.

TAKE HOME MESSAGE

When the available trial data are pooled together, it is clear that long-acting beta-agonists significantly increase the risk for asthma-related intubations and deaths, even when used in a controlled fashion with concomitant ICSs. Clinical guidelines should readdress the role long-acting beta-agonists have in the management of asthma.

The safety of long-acting beta-agonists: more evidence is needed

There is controversy regarding the possibility that long-acting beta-agonists (LABA) may paradoxically contribute adversely to asthma mortality. While studies and meta-analyses indicate increased risk, epidemiological data indicate a slow fall in asthma mortality since the introduction of LABA. Advocates for LABA propose that mandatory simultaneous use of inhaled corticosteroids satisfactorily reduce any potential risk. In the face of lingering doubts, others propose that LABA should be withdrawn from use. In this pro-con article, Kazani et al. provide the rationale for a modified randomized controlled trial that would define the level of risk more clearly, and provide the basis for a clear judgment to be made. Sears argues that current knowledge about the risks associated with LABA, especially when prescribed as monotherapy, provides sufficient evidence for clinicians and licensing authorities alike, and that the logistics and likely outcomes for a large prospective study are unjustified.

Asthma: time to confront some inconvenient truths

Despite major advances in the understanding of the pathogenesis of asthma and improvements in management, the accompanying benefits from public health initiatives and clinical practice have arguably been less than expected. For example, there are no effective public health strategies or treatment regimes that reduce the risk of developing asthma or influence its natural history. These represent priority areas for future translational research, which would need to investigate genetic and environmental interactions and vaccine strategies. In terms of asthma management it is tempting to focus on novel drug therapies; however, a case can be made that the priority is to undertake research that leads to improvements in the use of existing treatments through public health and primary care initiatives. Guidelines represent an important component of this approach, with recommendations for asthma imbedded within respiratory guidelines that can be implemented in the developing world where other acute and chronic respiratory disorders are common. This approach offers the best opportunity to close the gap between what is currently achieved in asthma management and that which is potentially achievable.

Use and safety of long-acting β2-agonists for pediatric asthma

Asthma guidelines recommend the use of long-acting β2-agonists (LABAs) as the preferred add-on therapy for adults and children over 5 years of age when asthma is inadequately controlled by inhaled corticosteroids alone. It has been suggested that LABA use may be associated with an increased risk of morbidity and mortality; however, this view is controversial since study findings have been inconsistent. While the safety profile of LABA monotherapy has been questioned, the value of concomitant inhaled corticosteroids to eliminate possible risks remains unproven. There is a paucity of efficacy and safety data for LABA use in children, and existing evidence is not sufficiently convincing to demonstrate a clear position for LABAs in the management of childhood asthma. The main aims of this article are to place LABAs in context in the management of childhood asthma and evaluate the current evidence for safety and efficacy.

Update on the safety of long-acting beta-agonists in combination with inhaled corticosteroids for the treatment of asthma

A number of concerns were voiced in 2006 regarding the safety of the use of long-acting beta-agonists (LABAs) for treatment of asthma. These concerns included whether use of this class of drug increases the risk for hospitalization, near death, or death due to asthma, whether the increased risk was greater in African Americans, and whether individuals who are homozygous for arginine at the 16th codon of the beta2-adrenergic receptor have a poorer response or even deteriorate when prescribed LABAs. Subsequent studies have addressed each of these concerns. It is hoped that the consistently reassuring data that have been generated during the last 3 years will reduce the concerns among physicians, patients, and regulatory authorities regarding the safety of combination LABA and inhaled corticosteroid use in patients with asthma and allow the proper use of this valuable combination treatment for appropriate patients.

An observational study of fixed dose combination fluticasone propionate/salmeterol or fluticasone propionate alone on asthma-related outcomes

OBJECTIVE

To identify the relationship between resource utilization and treatment of asthma in subjects who were first time users of controller therapies, either fluticasone propionate (FP) and salmeterol delivered in a single Diskus device (FSC) or FP monotherapy.

METHODS

A retrospective, observational cohort analysis evaluated pharmacy and medical claims from subjects from a commercial managed-care database, which is similar in makeup to the US privately insured population, with a diagnosis of asthma and ≥1 prescription for FSC or FP dispensed from 1/1/2001 to 4/30/2005. Outcomes of interest were asthma-related emergency department (ED) visits, inpatient (IP) visits, and a combined outcome (IP or ED visits). Predicted rates of asthma-related and all-cause intubations were also reported for each cohort. Multivariate analysis of events was conducted using logistic regression and Cox proportional hazard regression. All outcomes were adjusted for differences in baseline characteristics.

RESULTS

There were 58 270 subjects identified (FSC, n = 42 466; FP, n = 15 804). Mean age was 37.65 years and 35.75% was female. The use of FSC was associated with lower risk of having an asthma-related ED visit (adjusted OR 0.79; 95% CI, 0.72-0.87) and an asthma-related ED/IP visit (OR 0.80; 95% CI, 0.73-0.88). Asthma-related ED and ED/IP rates were also significantly lower for FSC than for FP. There were no differences observed in post-index asthma-related intubations rates.

CONCLUSION

In this observational study using a large managed-care database, subjects treated with FSC were at significantly less risk for developing serious asthma exacerbations and had lower resource utilization than a cohort of subjects treated with FP. This is clinically meaningful despite the inherent limitations of these types of observational studies.