Twelve percent of U.S. children younger than 18 years of age have asthma. Because many triggers exacerbate this chronic condition, successful management hinges upon symptom monitoring, which is often unreliable. To determine whether daily use of a peak flow monitor, which provides an objective measure of airway constriction, can reduce the number of asthma episodes, school absences, and medical visits, researchers had Kentucky schoolchildren with asthma use a peak flow monitor each morning and evening before taking their regular asthma medications. Most of the 77 children, ages seven to 11.9 years, were white and male. The monitor used for the first month contained a computer chip that recorded the date, time, and peak expiratory flow at each use. Children also kept a daily asthma diary of peak flow values.
After one month, half the children were given additional in-person training on managing asthma, while the second group continued receiving standard care. Each child's best peak expiratory flow value was identified in her or his asthma diary, and three "zones" of intervention were determined: green (80% to 100% of the best value) indicated good asthma control, requiring no change in medication; yellow (50% to 80% of the best value) indicated airway constriction and a need for intervention with prescribed medication; and red (less than 50% of the best value) indicated the need for immediate medical attention. Monitor use was decreased to once daily unless asthma symptoms necessitated more frequent measurement.
After four months, parents of children in both groups reported a significant decline in asthma episodes, health care visits, and missed school days. In addition, parents reported that having an objective measure helped them feel more in control of their child's symptoms.
The authors write, "objective self-monitoring [horizontal ellipsis] may have increased children's awareness of their disease status, leading to early intervention."
The study's lead author, Patricia Burkhart, told AJN that peak flow monitoring is recommended for those with persistent asthma and "those with intermittent asthma who don't perceive airway constriction until it is severe." She recommends the creation of "an individualized asthma action plan based on daily monitoring, to help patients determine when to adjust their medicines or seek emergency care."