Archive for the ‘global respiratory health’ Category

Farm exposure and childhood atopy, wheeze, lung function, and exhaled nitric oxide

Some interesting new results from the GABRIEL study examining children living on farms and the development of wheeze and other objective markers of asthma and allergies today.

The project, which involved nearly 9,000 children, reported in the Journal of Allergy and Clinical Immunology that children living on farms are protected against wheeze independently of atopy.

Nor is the so-called farm effect attributable to improved airway size or lung mechanics; the team found no farm-related effect on lung function or exhaled nitric oxide.

I’ll admit that these kind of findings – which “imply as yet unknown protective mechanisms” – are exactly what makes asthma so continually intriguing to me. We’re gradually, unevenly, unravelling a very complicated relationship between patterns of squarely cultural human behavior and ecology, the human immune response over time, and the development of chronic respiratory disease. And maybe viruses are involved too. 

The article is here.

 

Parents misperceive asthma control in kids

The rise of asthma control and impairment as the main indicators of management has renewed interest in a longstanding challenge: Variability in the perception and experience of asthma symptoms. Parents and children have been shown to differ in their assessments of the existence of asthma, let alone the presence or severity of specific symptoms. And the meaning of symptoms, and the ties to medication taking, are other matters entirely.

A new report from a large interview study suggests that worldwide, few children and adolescents achieve control of their asthma and experience frequent symptoms. A significant portion (11 percent) reported mild asthma attacks at least weekly, while 35 percent required oral corticosteroids or hospitalization at least annually.

The team interviewed 1,284 parents of children with asthma in six countries (Canada, Greece, Hungary, the Netherlands, South Africa and the UK) and 943 of the children themselves. The results highlight the impact of frequent morbidity on daily life: Asthma restricted the child’s activities in 39 percent of families and caused 70 percent to change their lifestyle. The article was published in the European Respiratory Journal.

One reason for the significant morbidity may be parental misperception of asthma control. Parents in the study tended to underestimate the severity of their child’s asthma while overestimating the level of control. While 73 percent of parents described their child’s asthma as mild or intermittent, 40 percent of children/adolescents had C-ACT scores ≤19, indicating inadequate control. In addition, even fewer (14.7%) achieved complete control as defined by the more stringent Global Initiative for Asthma (GINA) guidelines.

Parent misperception of control in childhood/adolescent asthma: the Room to Breathe survey

W.D. Carroll, J Wildhaber and PLP Brand

Global Asthma Report 2011

Worldwide, 235 million people have asthma. Although effective treatment is available, many people with asthma, especially in low- and middle-income countries, are unable to access or afford it.

A new report, and accompanying website, released today by the International Union Against Tuberculosis and Lung Disease (The Union) and the International Study of Asthma and Allergies in Childhood (ISAAC) highlights the issues surrounding asthma in the global context.

The report, authored by some of the leading asthma experts around the world, is described as an atlas of known “causes and triggers of the disease, the global prevalence, the progress being made and the significant challenges today and for the future.”

I expect to be posting more as I read through the report, but the key findings highlighted by the press release are the following:

  • ISAAC data show that asthma in children is increasing in low- and middle-income countries, where it is more severe than in high-income countries.
  • The World Health Survey found an 8.2% prevalence of diagnosed asthma among adults in low-income countries and 9.4% in the richest countries. Middle-income countries had the lowest prevalence at 5.2%.
  • Smoking and secondhand smoke are two of the strongest risk factors — and triggers — for asthma.
  • Although asthma is frequently thought of as an allergic disease, this does not apply to all cases, and the non-allergic mechanisms need to be the focus of more research.
  • Surveys around the world found asthma treatment falling short, with few patients consistently using the inhaled corticosteroids that effectively manage the disease.  For example, the Asthma in America survey found only 26.2% of patients with persistent asthma used these medicines.
  • While many countries now have asthma management guidelines, many health workers do not know how to diagnose or treat asthma and health systems are not organised to handle this type of long-term, chronic disease.
  • A 2011 Union survey of the pricing, affordability and availability of essential asthma medicines in 50 countries found dramatic variations. For example, one generic Beclometasone 100µg inhaler in a private pharmacy cost the equivalent of nearly 14 days’ wages — and a patient with severe asthma requires about 16 of these inhalers per year.
  • The Asthma Drug Facility established by The Union has been able to bring down the cost of treating a patient with severe asthma to approximately US$ 40 per year.
  • When people do not have access to ongoing care, they often end up in emergency rooms and hospitals — a costly and unnecessarily disruptive process for all involved.
  • Although economic data are unavailable for almost all low-income countries, a 2009 systematic review found annual national costs (in 2008 US dollars) ranging from $8,256 million in the United States to $4,430 million in Germany.
  • Success stories from five high- and low-income countries that have implemented asthma management activities show that well-managed asthma saves money – and enables people to get on with their active lives. For example, in Finland, the mortality, number of hospital days and disability due to asthma fell 70–90% between 1994 and 2010 and a conservative estimate of the savings was $300 million in 2007 alone.

Obviously the economic data on costs in the US needs to be updated. A recent CDC report calculated direct economic costs nearly six times higher. Nevertheless the main message remains valid. There is an urgent need to overcome the frustrating gap between what we should be able to do, and what we’ve so far been able to accomplish. As articulated by Nils Billo, Executive Director of The Union:

The tools to treat asthma are already available – there is no reason to delay. Moreover, when asthma is not diagnosed, not treated or poorly managed, and when people can not access or afford treatment, they regularly end up having to miss school or work, they are unable to contribute fully to their families, communities and societies, they may require expensive emergency care, and everyone loses.  The obstacles to well-managed asthma can be overcome.  Asthma is a public health problem that can – and should be addressed now.

 

Disease labels in national surveys – the case of COPD

The new CDC Framework for COPD Prevention, much better thought of as a well developed agenda for applied public health, estimates that half of the people with COPD in the US have not been diagnosed.

The report – developed by a group of experts during a workshop in 2010 – proposes first among its four goals that the US improve the collection, analysis, dissemination, and reporting of COPD-related public health data. In particular, it highlights the need to develop and initiate new data collection within existing surveys, an obviously efficient and valuable objective. It recommends:

Refining the definition of COPD in existing surveillance systems by adding the terms ‘COPD,’ and ‘chronic obstructive pulmonary disease’ to the currently used ‘emphysema’ and ‘chronic bronchitis’ terms.

This sentence brought me to a stop, frustrated that this change still needs to be made.

Our public health agencies must soon recognize some basic limitations of our surveillance systems: If they attempt to assess prevalence by asking people to report a physician diagnosis of some disease, they have no choice but to coevolve with diagnostic and popular nomenclature.

In this case, COPD has now been the dominant label for several years. Changes in awareness and labeling have been driven by many forces, including an improved understanding of the pathophysiology and natural history of the disease. But also by:

  • the rise of national organizations with names like the COPD Foundation, which was founded way back in 2004,
  • the marketing and education efforts of our own federal agencies (see the NHLBI page for example, or, well, the title of the report, which one downloads from the COPD page at CDC),
  • an increase in direct to consumer marketing of pharmaceuticals for the disease (such as this page for a branded formulation of tiotropium).

If we expect accurate and reliable prevalence estimates, we need to require that national surveys such as BRFSS, NHANES, and NHIS match the terminology in circulation. It is no longer acceptable to field surveys characterized by diverging epidemiological measures and popular labels.

A quick look at search frequency for COPD and emphysema (via Google Trends) shows that, in the US, search for COPD is more than twice as frequent compared to that for emphysema, and has been since about 2007. The dramatic, transient increases in search frequency for emphysema, which followed highly-publicized celebrity deaths attributed to emphysema (Johnny Carson in January of 2004) and mis-attributed to emphysema (Amy Winehouse in 2008), underscore the dynamic popular landscape of disease labels but also show the resilience of the longer-term trend.

Moreover, there are not large regional variations here; search for COPD (in blue) dominates that for emphysema (in red) across all regions of the country.

Inertia in the methods of our national surveys undermines the utility and value of their resulting estimates and, while it may make for more stable measures, assures that they are steadily providing information about an increasingly inappropriate category.

Public health, population health, and mHealth

The stabilizing prevalence of asthma and the origins of the disease

Statistics Canada recently reported that the prevalence of asthma among 2-7 year old children had declined to its lowest level in more than 10 years, from 13.2 percent in 2000-01 to 9.8 percent in 2008-09, the most recent year for which data are available.

The findings, drawn from the National Longitudinal Survey of Children and Youth, echo many others that have previously pointed to a plateau and decline in asthma prevalence in the last decade in many high-income countries. Reports in respiratory journals began to appear as early as 2000 suggesting that the number of cases of asthma appeared to be stabilizing in some countries and even subsiding in others. These data imply that in Canada, exposure to the cause(s) of the epidemic is no longer increasing, and could even be declining.

The changing trends in asthma prevalence highlight fundamental shortcomings in our current epidemiological theories. Just when it appeared that we finally had the evidence and theoretical framework to explain the increasing prevalence of asthma worldwide, we now rather suddenly have to account for an inexplicable and unanticipated decline.

The hygiene hypothesis, for example, emerged as a predominant explanation for the epidemic of asthma. It suggested that lifestyle changes accompanying westernization and modernization had reduced exposure to microbes that had previously played a valuable role in training the immune system during childhood. It proved to be a useful explanation that made sense of important findings of lower rates of asthma among children raised on farms, for example. But the hygiene hypotheses could never really adequately account for rising rates of asthma in inner cities, and now, of course, it lacks the power to explain the decline in asthma.

Official reports announcing the declining prevalence of asthma in Canada pin it on reductions in the rates of tobacco smoking and improvements in other environmental exposures. In the report, Eleanor Thomas from Statistics Canada writes:

“A number of environmental factors may be related to the recent declines in childhood…asthma: changes in the population structure; changes in diagnostic practices; decreases in the prevalence of respiratory allergies; improvements in air quality; changes in hygiene practices (particularly, in child care settings); and reductions in children’s exposure to cigarette smoke at home….[R]educed exposure to tobacco smoke may be contributing to the decreased prevalence of…asthma among young children.”

But the situation in asthma epidemiology is actually quite a bit more complex. Statistics Canada has it mostly wrong about the environmental exposures it scrutinizes. And they have it wrong in a way that productively highlights an important difference between public health and population health.

Primary and secondary risk factors in asthma epidemiology

The key difference hinges on the distinction between primary and secondary risk factors. Statistics Canada, and much of asthma related public health at the moment, is focused on tracking secondary risk factors for asthma. Secondary risk factors are those inputs that influence which individuals in a population will develop asthma. By contrast, primary risk factors are those that determine the overall level of asthma in the population.

Tobacco smoke exposure offers a useful example. Over the years, research has repeatedly established that tobacco smoke exposure increases the odds that a given child will develop asthma. However, we also know that tobacco smoke exposure cannot, in and of itself, be responsible for the increase in asthma cases in the latter half of the twentieth century. The asthma epidemic occurred in populations at a time when rates of tobacco smoking were declining. Tobacco smoke exposure and asthma prevalence, in other words, demonstrate counter trends at the population level.

Statistics Canada’s own evidence on tobacco use bears this out. Here is a figure showing the prevalence of cigarette smoking between 1985 and 2001.

Cigarette smoking (above) declined from 35.1% in 1985 to 21.7% in 2001 while asthma prevalence (below) rose from approximately 3% in 1984 to more than 13% in 2000-01.

In addition to tobacco smoking, Statistics Canada highlighted improving environmental factors — improvements in air quality specifically — as potential contributors to the recent decline in asthma rates. But again we have evidence that atmospheric pollutants cannot be responsible for the epidemic of asthma because exposure to these risk factors has been reduced at the population level over the same time period. The following figure illustrates changes in the mean concentration of particulate matter (2.5 microns) as measured by Canadian National Air Pollution Surveillance network between 1990 and 2001.

The story is the same whether you look at mean annual concentrations of particulate matter (PM2.5 concentration in 2001 was 27% lower than in 1990, while the PM10 level was 34% lower), carbon monoxide (34% lower in 2001) sulfur dioxide (32% lower in 2001), or nitrogen oxides (NO in 2001 21% lower, while NO2 concentration15% lower). [For the full report see Environmental Protection Series National Air Pollution Surveillance (NAPS) Network. Air Quality in Canada: 2001 Summary and 1990-2001 Trend Analysis. Report EPS 7/AP/36 May 2004.]

In short, air quality in Canada improved in many places during the time period when there was a rather uniformly increasing trend in the prevalence of asthma, and continued to do so when the rates of asthma stabilized and began to decline. One cannot attribute only the recent decline in asthma prevalence to improving air quality.

What we see in these explanations is that many clinicians, researchers and epidemiologists and public health agencies tend to focus on associations and explanations involving secondary risk factors, such as tobacco smoke or air pollution, and to develop and field interventions that address them. There are certainly valuable reasons for doing so. These kinds of exposures are more ascertainable in clinical encounters, they are often modifiable by patients, and their control and mitigation may have an important positive effect on the individual and the day-to-day manifestation of their asthma. Indeed, the evidence from Statistics Canada suggests exactly that:

“A key finding is that the percentage of children with asthma who reported an asthma attack in the past 12 months fell steadily from 53 per cent in the mid-1990s to 36 per cent last year.”

In short, children with asthma in Canada are being less frequently exposed to asthma triggers and, as a result, reporting fewer asthma attacks. Good news. Reduced tobacco smoke exposure certainly deserves credit for contributing to this decline.

It should be evident, then, that there are clear, important risk factors for asthma that play a significant role in the natural history of the disease in a given patient, but which, all the same, cannot be responsible for the epidemic.

These secondary risk factors are not (necessarily) the same things that we would choose to focus on if we were trying to change the overall rate of asthma in the population. As Jeroen Douwes and Neil Pearce, two international asthma experts, wrote in a 2006 editorial:

“Thus, the ‘established’ risk factors for asthma do not appear to explain the global prevalence patterns and time trends. These risk factors were ‘discovered’ primarily on the basis of clinical studies and case reports of exacerbations in asthma patients. It is natural for physicians and patients to assume that the factors involved in secondary causation may also be important for primary causation. However, for most of the ‘established’ risk factors, the evidence of primary causation is relatively weak, and risk factors such as allergen exposure do not appear to explain the prevalence patterns and time trends.”

The population health possibilities

In his 1985 article “Sick Individuals and Sick Populations,” Geoffrey Rose made the observation that small changes in the risk of a disease, when summed across a population, could result in dramatic shifts in the prevalence of a disease. Although he didn’t consider the concept of primary and secondary risk factors, his work demonstrated how risk factors insignificant to an individual could be meaningful to the population, and prompted a reevaluation of public health preventive strategies.

The growing evidence of a plateau and decline in asthma should have had similarly major implications for our view of the (partially understood) potential etiologic mechanisms underlying the asthma epidemic and the origins of asthma. So far, however, the signs of shift to a population health perspective have been minimal. In part, our ability to think about and understand the complex causes of the long increase in asthma and the plateau and decline has been hampered by the continuing orientation of epidemiology and public health to surveillance and analysis of secondary risk factors.

In the case of asthma, it remains a struggle to identify primary risk factors from available public health data. We are limited to retrospective and outdated data on only the most severe exacerbations (those that result in hospitalizations and, in some states, emergency room visits). Altogether, that amounts to just a tiny fraction of the daily burden of asthma morbidity.

Moreover, our surveillance system is designed to ignore potentially valuable information about where and when the attack began, whether that is at home, at school, at work, or out in the community. Typically the only geographic information available is the billing address. As a result, we cannot understand the small area variation in rates of asthma that we know exists.

New approaches to chronic disease surveillance and epidemiology are emerging that, if guided by a population health perspective, have enormous potential to advance our understanding of chronic diseases. It is already clear that these systems will be increasingly driven by participatory ethics (see the 2010 article by Freifeld et al. in PLoS Medicine) and will collect and rapidly make sense of valuable new streams of data, drawn from distributed networks of sensors and connected devices. They will bring growing numbers of people (see notes below) and their daily experiences of health, disease, medicine and the environment under increasing statistical scrutiny (cf. RWJF Project HealthDesign), with many potential benefits. It is likely that such approaches will generate new, useful clinical knowledge. A recent analysis of data volunteered by individuals using CureTogether, for example, has identified a new symptom marker that predicts negative response to a specific migraine treatment.

But the materialization of an epidemiological advance from these tools will be more complex and less certain. It will, in fact, turn on our ability to use them to marshal a new hunt for primary causes – that will complement the traditional clinical and public health focus on secondary risk factors that has dominated them so far.

Even then, there may still be very difficult challenges. For example, it is worth considering the possibility that it may be too late to search for the primary cause(s) of a number of chronic diseases in the urban areas of high-income countries. In these settings, exposure to the primary causes of a given disease may already be ubiquitous across the population. Without variability in exposure to the disease’s primary causes, all that would be revealed are the effects of secondary risk factors. Similarly, repeated investigations over short periods will only be informative if they capture a dramatic, and thus unusual, change in lifestyle or environmental exposures.

In other words, our odds of making fundamental discoveries are tied to our ability to develop tools and systems that help us collectively uncover a new list of primary risk factors and hypotheses. To do this might mean we engage communities that display a broad range of prevalence (urban vs. rural areas of low income countries), or populations that abruptly change their environment and lifestyle (immigrants, refugees, adoptees, etc.) Such efforts would have a much greater probability of identifying primary causes of the chronic diseases we’re targeting, especially if the confounding role of secondary causes is also accounted for.

Our new systems should help us explain the overall rates of asthma in populations, its global gradients and time trends, and do so with some evolutionary probability. We need to pause to reflect on the u-turn that the prevalence of asthma has done and re-double our efforts to piece together the rules that underlie the surge, pause and decline in the prevalence of asthma. It will also almost certainly mean evolving our approaches to better sample experience, understand context, lifestyle and environment, and to look for connections where there may not be evidence of an effect on individuals.

Notes
In a recent article in Science on open mHealth architecture, Deborah Estrin and Ida Sim noted that if only 1 out of every 250 patients in the US taking antidepressants participated in a collaborative study of their long term efficacy, more than 100,000 patients enrolled would exceed the total number of patients enrolled in all antidepressant studies conducted worldwide since 2005.

Oxygen is an essential medicine: A call to international action (Now only $29.27)

The International Journal of Tuberculosis and Lung Disease, the journal of the International Union, just published an article I was really happy to see. It argues that while hypoxemia is a big public health problem in developing countries, a lack of access to oxygen treatment and pulse oximetry gets “little or no attention” in global health circles. From what I can gather, the article is right on target. In the abstract, the authors write:

“Improving access to oxygen and pulse oximetry has demonstrated a reduction in mortality from childhood pneumonia by up to 35% in high-burden child pneumonia settings. The cost-effectiveness of an oxygen systems strategy compares favourably with other higher profile child survival interventions, such as new vaccines. In addition to its use in treating acute respiratory illness, oxygen treatment is required for the optimal management of many other conditions in adults and children, and is essential for safe surgery, anaesthesia and obstetric care.”

Unfortunately for a self-proclaimed “call to international action,” access to the full text of the article costs $29.27. While presumably written to get the attention of the western global health community, it seems that the Union or IJTLD might be better served by seeing to it that these pieces are made freely available. I’m sure that the argument and evidence could be valuable to public health and clinical teams in low and middle income settings working to draw attention to the predicament of oxygen therapy right now. If only they could afford it.

Measuring respiratory health in longitudinal studies

The journal Biodemography and Social Biology has just published a special issue devoted to the use of biomeasures in the Panel Study of Income Dynamics (PSID), and more generally, to their value and role in longitudinal social science.

The articles focus on a variety markers (from cardiovascular to metabolic) and includes a handful of thorough reviews of the integration of these measures in panel studies in general. One article, by Edith Chen and Wei-Jun Jean Yeung, summarizes the measurement of respiratory health in longitudinal social science surveys.

It’s a detailed and useful review of pulmonary function measurements and a helpful synthesis of the important perspective – and research synergies – that such measurements add to social science surveys. The authors also summarize some of the measurement issues and the limitations that equipment cost and training pose to the widespread adoption of spirometry.

This group of articles got me thinking about the lack of longitudinal health social science surveys in global health – particularly ones conceived and fielded by local investigators and institutions. I’m sure there must be some and I’d love to learn about them if they exist. It seems to me that affordable spirometry equipment with in-built technology to assure high quality measurements is really a priority if we’re to see valuable panel data collected from low and middle-income settings anytime soon.

New AAAAI report on indoor air cleaners and filters

I think one of the most questions I was asked most often while working at the CDC was whether indoor air filters were effective at reducing symptoms of asthma and allergy.

This week the American Academy of Allergy, Asthma and Immunology has published a report on air filters and air cleaners that should help answer that question. The entire report is available free via PubMed.

Actually it goes well beyond that, with a thorough review of air filtration, the characteristics of airborne particulates – including allergens and particulate matter – and the range of available filter/cleaning strategies and technologies, from portable room air cleaners, to HVAC and powered electric filters.

One of the more interesting conclusions of the report is that air cleaning and filtration be viewed as a strategy for minimizing disease progression rather than as a treatment. As the report puts it, “It is not logical to expect that the observed disease state symptoms, often the result of previous prolonged exposures either in the home, other environments, or both, will abate within a few weeks or even months after the placement of an air-cleaning device or filter in the home environment. Other factors, especially source control and ventilation, might play a more important role than attempts to clean the air after the fact by means of filtration.”

They recommend that more rigorous and lengthy trials are needed before definitive recommendations on the efficacy of air filtration in improving disease can be made. Obviously there is a big role in these studies for more robust baseline and prospective data on symptoms and symptom severity, medication use and various objective markers (lung function). But I really like their idea of blinding and placebo-controlling the studies.

The group concludes that, given the current evidence, use of effective air filtration does reduce indoor levels of ambient particulates, that “that might trigger disease processes themselves.”

What to use? “Portable room air cleaners with HEPA filters, especially those that filter the breathing zone during sleep, appear to be beneficial. For the millions of households with forced air HVAC systems, regular maintenance schedules and the use of high-efficiency disposable filters appear to be the best choices.”

Our study of rural asthma is underway

Rural asthma study launching in the Midwest

Novel technology automatically tracks where and when attacks occur

Beginning next week, Madison-based Reciprocal Sciences, with funding from the US Centers for Disease Control and Prevention, will launch a new study to learn more about the problem of rural asthma in the Midwest. The study follows a recent report by the CDC that rates of asthma in rural areas have been underestimated.

“Our analyses of national survey data suggest that asthma is as prevalent in rural areas as in urban areas,” says Teresa Morrison, medical epidemiologist in the Air Pollution and Respiratory Health Branch at CDC. “Our goal is to document patterns of asthma symptoms among rural residents in Midwestern states, and learn more about possible environmental exposures that potentially lead to asthma attacks.”

In the past, studies have relied on interviews and questionnaires to collect data on asthma. But now, volunteers who live in rural areas in the Midwest will be able to record their symptoms when and where they happen, using an innovative tool that Reciprocal Sciences unveiled last year. The device, called the Spiroscout, is a GPS-enabled inhaler that pinpoints the exact geographic location and time when the inhaler is used.

“For the first time, scientists will have definitive information about exactly where and when rural residents have symptoms,” says study director David Van Sickle, PhD, “and we can use that to identify important patterns in the disease.”

Participants in the six-month study will also be testing additional asthma management tools developed by Reciprocal Sciences, including a text messaging system designed to help people with asthma remember to take their daily medication.

Participation in the study is limited to 150 participants. Interested individuals can call (608) 554-0750, email info@reciprocalsciences.com or visit the project website for more information.

Asthma epidemiology review (February 16, 2010)

Recently-revised NIH guidelines encourage physicians to more closely monitor patients to ensure that treatments are controlling their symptoms and improving quality of life. The results has been growing interest in measures of asthma control yet relatively little work done to compare the various measures against other methods of classifying asthma. This week, JACI and ERJ published some important new articles that use data collected from therapy studies to examine asthma control and composite measures of asthma control, and their relationship to each other over time. I’ve also included a report of some surprising gender differences in the influence of socioeconomic variables on lung function decline.

Overall asthma control: The relationship between current control and future risk (E. Bateman et al. – JACI)

Very interesting retrospective analysis of five studies which examines the relationship between asthma control (assessed by questionnaire and guideline criteria) and the risk of future instability and exacerbations in asthma. Bateman and colleagues report that the percentage of patients achieving asthma control increased with time, irrespective of treatment, and not suprisingly, that asthma control score at baseline associated with exacerbation rates. In addition, the authors used Markov analysis to examine the transitional probability of change in control status throughout the studies. The finding: “A Controlled or Partly Controlled week predicted at least Partly Controlled asthma the following week (≥80% probability). The better the control, the lower the risk of an Uncontrolled week. The probability of an exacerbation was related to current state.”

Socioeconomic risk factors for lung function decline (Johannessen et al. – ERJ)

Interesting new report from a cohort study of more than 1,600 adults who performed spirometry in 1996-97 and again in 2003-6 that found gender-specific associations between different aspects of SES (socioeconomic status) and lung function decline. “Lower education and low occupational status were associated with larger male lung function decline…SES did not affect female lung function decline. However, marital status was a significant predictor; unmarried females had less decline than both married and widowed females” in both FEV1 and FVC.

Lessons learned from variation in response to therapy in clinical trials (Szefler and Martin – JACI )

“In the past, we viewed lack of response to asthma medications as a rare event. Based on recent studies, we now expect significant variation in treatment response for all asthma medications.” Szefler and Martin discuss how findings from multi-center asthma research networks (ACRN and CARE) are providing valuable new information about interindividual variability in response to a number of important controller medications. Using patient “characteristics, such as age and allergic status, and biomarkers, such as bronchodilator response, exhaled nitric oxide, and urinary leukotrienes,” can help physicians predict response and “personalize asthma treatment at the time of initiating long-term control therapy.”

Measuring asthma control: a comparison of three classification systems (O’Byrne et al. – ERJ)

In this paper, O’Byrne and colleagues compared three popular methods of assessing asthma control: The Asthma Control Questionnaire (ACQ-5) and two criteria based measures from the Global Initiative for Asthma (GINA) and Gaining Optimal Asthma ControL (GOAL) study. The review analyzed data from more than 8,000 subjects in three trials of the same asthma treatments. GINA and GOAL criteria provided similar assessments of asthma control, however, the ACQ-5 “detected clinically important improvements” in a large number of patients that according to other criteria remained uncontrolled. “ACQ-5 is more responsive to change in a clinical trial setting than a categorical scale.”