Yoos HL, Kitzman H, McMullen A, et al. Ann Allergy Asthma Immunol. 2002;88:283–291
Purpose of the Study.
The purpose of this study was to evaluate the effects of 3 different regimens of symptom monitoring on asthma morbidity outcomes.
One hundred sixty-eight children aged 6 to 19 years who had >3 asthma-related health care visits in the previous 12 months. The children were recruited from 11 different primary care sites and of diverse racial, geographic, and socioeconomic backgrounds.
Patients were randomized into 1 of 3 treatment groups. Treatment groups were: group 1, subjective symptom monitoring; group 2, peak expiratory flow rate (PEFR) monitoring when symptomatic; and group 3, PEFR monitoring twice daily and when symptomatic. In the beginning of the study, all families received education on asthma triggers, asthma symptom recognition, symptom management, and medications. A 2-week practice period included formulating a personal action plan that specified changes in management strategy based on symptoms or PEFR. A weekly diary was obtained for 3 months. Outcome measures included an asthma severity score (a composite score of symptom frequency, symptom duration, activity limitation, nighttime symptoms, and days missed from school), forced expiratory volume in 1 second (FEV1), symptom days, and health care utilization.
Children who used PEFR meters when symptomatic had a lower asthma severity score, fewer symptom days, and less health care utilization than children in the other 2 treatment groups. Minority and poor children had the greatest improvement using peak flow meters (PFMs) when symptomatic. Results were less dramatic in white families. Thirty percent of families discontinued daily PFM use by 1 year after exiting the study, while 94% of families continued to use PFMs when symptomatic.
Not all children with asthma need PFMs. Children and families who face extra challenges as a result of illness severity, sociodemographic, or health care system characteristics clearly seemed to benefit most from PFM usage.
This article supports the National Heart, Lung, and Blood Institute guidelines, which recommend objective symptom monitoring for children with moderate-to-severe asthma. Often it is felt that patients will only adhere to the most simple of medical treatment strategies, which in this study would have been the group with subjective symptom monitoring. Instead, this study revealed that the intermittent use of PEFR monitoring not only was the most beneficial, but also was easy enough for most families to continue 1-year postintervention. Although not all children receive the same level of benefit from PEFR, a PFM should be offered to all patients >5 who have persistent symptoms. An important feature, which was not well-addressed, was the benefit all the children received from the intensive asthma education at the start of the study.