Preferred asthma diagnostic tool for children is underused
■ Only 52% of doctors use spirometry, while 80% continue to rely on less-accurate peak flow meters, a new study says.
By Christine S. Moyer — Posted Oct. 8, 2010
Primary care physicians are not using the recommended method to diagnose and manage asthma in children enough, according to a new study.
Such practices could delay an asthma diagnosis or cause physicians to misclassify the condition's severity, said lead study author Kevin Dombkowski, DrPH.
The National Asthma Education and Prevention Program's guidelines recommend that physicians use spirometry to diagnose asthma and monitor lung function in asthmatic patients at least once a year.
But the study, published online Sept. 6 in Pediatrics, found that many family physicians and pediatricians continue to use a peak flow meter to monitor patients' lung function. Peak flow assessment is not considered a reliable method for diagnosing asthma because its results may be highly variable, the study said.
The study authors recommend that family physicians, pediatricians and their staffs receive additional training in using a spirometer and interpreting the results. They also suggest that similar instruction be added to the pulmonology rotation for pediatric and family medicine residents.
"There are some real troubling gaps in terms of [physicians'] comfort level and ability to interpret spirometry. It indicates that training is really going to be necessary," said Dombkowski, research associate professor with the Child Health Evaluation and Research Unit at the University of Michigan Medical School Division of General Pediatrics.
Asthma is one of the most common long-term diseases of children younger than 18, affecting nearly 7 million children in 2008, according to the most recent data from the Centers for Disease Control and Prevention. That year, 16.4 million adults had the condition.
For their study, researchers examined responses of 150 family physicians and 210 pediatricians to a survey on spirometry. The doctors were asked about their knowledge, attitudes and practices regarding the lung function test.
Researchers found that 52% of the physicians reported using spirometry in clinical practice (link). Use was more common among family physicians (75%) than pediatricians (35%).
Eighty-percent of participants used peak flow meters. Physicians were more likely to feel comfortable interpreting peak flow meter results (79%) than spirometric results (35%).
The study's authors asked physicians two separate questions, one regarding spirometry use and the other peak flow use. Ten percent of physicians said no to both questions, meaning they used neither method to assess lung function.
"A lot of pediatricians may think [a spirometer] is too difficult for children to use. The truth is that by age 5 or 6, children pick it up pretty readily," said James Gern, MD, a pediatric allergist and immunologist at the University of Wisconsin Hospital and Clinics in Madison.
"There is tremendous utility in using spirometry," he said. "It can tell you a lot about the function of lungs, the level of obstruction and differentiate asthma from other disorders that have the same symptoms but a different etiology."