Characteristics of Asthma Visits to Physician Offices in the United States: 2012–2015 National Ambulatory Medical Care Survey

Questions for Lead Author Lara Akinbami, Health Statistician, of “Characteristics of Asthma Visits to Physician Offices in the United States: 2012–2015 National Ambulatory Medical Care Survey.”

Q: Why did you decide to do a report on asthma visits to physician offices?

LK: Asthma is a common chronic condition in the United States: in 2016 8.3% of the population had asthma.  Each year, there are nearly 2 million emergency department visits, over 300,000 hospitalizations and more than 3.500 deaths in the United States due to asthma.

These adverse outcomes arise when episodic asthma attacks become severe.  A key part of preventing these adverse asthma outcomes is the prevention of attacks, and early recognition and management of symptoms.  Physicians in non-emergent community settings have a key role in partnering with people with asthma in identifying and monitoring symptoms, and developing a plan to avoid things that trigger attacks, and providing a medication plan to reduce symptoms when they do arise.  There are evidence-based national asthma guidelines that provide recommendations on how to best manage asthma that are directed toward care in physician offices (https://www.ncbi.nlm.nih.gov/books/NBK7232/).  Furthermore, asthma is now increasingly recognized as a risk factor for chronic obstructive pulmonary disease, the fourth leading cause of death in the US, and diagnosis and management of asthma is as an important part of monitoring lung health through the lifespan.

For all these reasons, assessing trends in visits to physician offices is useful in tracking the characteristics of asthma patients, the reasons asthma patients seek care (routine monitoring or acute care), and the services provided in these visits.  These help answer questions that can direct interventions, for example, “Are certain groups less likely to seek care in office settings?” Or “Are guideline recommendations being followed?”

Q: How did the data vary by age, sex and race?

LK: Asthma visit rates tend to reflect the prevalence of asthma in the population, but with some notable exceptions.  Asthma prevalence is higher in children than in adults, and children have higher asthma physician office visit rates than adults.  However, although asthma prevalence peaks in mid-childhood, we see high rates of asthma visits among children 0-4 years of age.  This is because these very young children have smaller airways.  They are more likely to show symptoms with any conditions that further narrows the airways, such as respiratory infections.

Another interesting pattern is that asthma prevalence is higher among boys than girls, in contrast to among adults in whom women have higher asthma prevalence than men.  Asthma visit rates also reflect this pattern with boys having higher visit rates than girls, and women having higher visit rates than men.  However, once the differences in prevalence are accounted for by looking at just people who have asthma, boys with asthma have similar asthma visit rates as girls with asthma, and the same is true for men and women with asthma.  The one exception is that very young boys ages 0-4 yeas with asthma still have higher rates of asthma visits than 0-4 year old girls with asthma.

By race and Hispanic origin, asthma visit rates are similar between groups with no differences seen between asthma visits rates for non-Hispanic white, non-Hispanic black and Hispanic persons.  Asthma visit rates were lower for persons of non-Hispanic other race.  However, this pattern does not reflect asthma prevalence which is higher for non-Hispanic black persons than non-Hispanic white and Hispanic persons.

Q: Is this the first time you have published a report on this topic?

LK: The Centers for Disease Control and Prevention publishes regular asthma surveillance reports on asthma that provide analysis of trends and estimates of the most recent data for asthma prevalence, health care utilization and death.  The CDC also provides a web page with the most recent asthma data: https://www.cdc.gov/asthma/most_recent_national_asthma_data.htm.  However, this report is only the second since 1996 to analyze asthma visits to physician offices in depth, including the degree to which services in asthma visits reflect recommendations in the national asthma guidelines.  These guidelines were originally released in 1991 with the most recent update in 2007.  When findings of this report which analyzed data from 2012-2015 is compared to the 1996 report that analyzed data from 1993-1994, we found that despite an increase in asthma prevalence over this period, the annual average number of asthma visits declined from 11 million in 1993-1994 to 10.2 million in 2012-2015.  Medications in 2012-2015 included newer medications that target airway inflammation.  A similar percentage of asthma visits were seen by primary care physicians as opposed to asthma specialists, 65% in 1993-1994 and 60% in 2012-2015.  However, there was less progress in increasing the implementation of national asthma guidelines than would be expected given the effort to increase uptake of key recommendations such as providing an asthma action plan and documenting asthma severity and control.

Q: Was there a specific finding in your report that surprised you?

LK: Given the emphasis on the importance of assessing and documenting asthma control, only 40.9% of asthma visits to physician offices had a level of asthma control documented.  The distribution between levels of asthma control was expected with 29.1% of patients with well controlled asthma, 10.5% with not well controlled asthma and 1.3% of patients with very poorly controlled asthma.  However, that 59.1% of asthma patients had no level of control documented was surprising given the concerted efforts to have asthma control assessed and documented.  These efforts included quality of care measurements, physician continuing education, a Guideline Implementation Report (https://www.nhlbi.nih.gov/files/docs/guidelines/gip_rpt.pdf), and local quality improvement projects.

Q: What is the take home message for this report?

LK: Asthma is a common chronic condition and a common reason for physician office visits.  Given its high burden in morbidity, health care use, and mortality, it is important to assess the content of asthma physician office visits given that physicians are the on the “front line” of asthma care and provide the majority of asthma care.  Rates for asthma visits to physician offices started to decline before total office visit rates declined.  Asthma education, objective monitoring (pulmonary function  testing) and level of asthma control were documented in a minority of visits.  Quick-acting relief medication remained the most frequently mentioned medication class.  Additional research can explore the underlying reasons for trends, and future policy can target low implementation rates of guideline recommendations.