OBJECTIVE: Spirometry is an important component of the National Asthma Education and Prevention Program guidelines for asthma, yet published data show variable associations between forced expiratory volume in 1 second percentage (FEV1%) predicted, symptoms and health care utilization. The objective of this analysis was to examine the association between FEV1% and future risk of exacerbations among a well-characterized population of children with asthma. METHODS: Using data that are available from the Childhood Asthma Management Program, we examined the relationship between prebronchodilator FEV1% and important clinical outcomes. Multiple observations of FEV1 were available for each patient; multivariate regression analysis, using a general estimating equation approach, was used to control for the correlation between repeated measurements among individuals and potential confounders. FEV1% was categorized into 4 levels and as a continuous variable. Outcomes of interest included mean symptom score (0-3), episode-free days, and asthma-related events (oral steroid use, emergency department visits, and hospitalizations) during the ensuing 4-month period. Our analysis was limited to the placebo group (N = 417). RESULTS: We observed a clear relationship between prebronchodilator FEV1% and important clinical outcomes. In multivariable models that simultaneously controlled for covariates of interest, age at baseline, time, previous event history, and nocturnal awakenings, a significant relationship between FEV1% and asthma symptoms and serious asthma exacerbations (oral steroids, emergency department visits, and hospitalizations) was observed. Compared with children with an FEV1% > or = 100%, children with FEV1% 80% to 99%, 60% to 79%, and < 60% were 1.3, 1.8, and 4.8, respectively, more likely to have a serious asthma exacerbation during the ensuing 4 months. CONCLUSIONS. In children with mild to moderate asthma, FEV1% predicted is independently associated with future asthma symptoms and health care utilization. Previous asthma-related hospitalizations and nocturnal symptoms also were independently associated with risk for future adverse events. FEV1 is an important component of asthma health status and asthma severity classification.
OBJECTIVE: Spirometry is an important component of the National Asthma Education and Prevention Program guidelines for asthma, yet published data show variable associations between forced expiratory volume in 1 second percentage (FEV1%) predicted, symptoms and health care utilization. The objective of this analysis was to examine the association between FEV1% and future risk of exacerbations among a well-characterized population of children with asthma. METHODS: Using data that are available from the Childhood Asthma Management Program, we examined the relationship between prebronchodilator FEV1% and important clinical outcomes. Multiple observations of FEV1 were available for each patient; multivariate regression analysis, using a general estimating equation approach, was used to control for the correlation between repeated measurements among individuals and potential confounders. FEV1% was categorized into 4 levels and as a continuous variable. Outcomes of interest included mean symptom score (0-3), episode-free days, and asthma-related events (oral steroid use, emergency department visits, and hospitalizations) during the ensuing 4-month period. Our analysis was limited to the placebo group (N = 417). RESULTS: We observed a clear relationship between prebronchodilator FEV1% and important clinical outcomes. In multivariable models that simultaneously controlled for covariates of interest, age at baseline, time, previous event history, and nocturnal awakenings, a significant relationship between FEV1% and asthma symptoms and serious asthma exacerbations (oral steroids, emergency department visits, and hospitalizations) was observed. Compared with children with an FEV1% > or = 100%, children with FEV1% 80% to 99%, 60% to 79%, and < 60% were 1.3, 1.8, and 4.8, respectively, more likely to have a serious asthma exacerbation during the ensuing 4 months. CONCLUSIONS. In children with mild to moderate asthma, FEV1% predicted is independently associated with future asthma symptoms and health care utilization. Previous asthma-related hospitalizations and nocturnal symptoms also were independently associated with risk for future adverse events. FEV1 is an important component of asthma health status and asthma severity classification.
Authors: Robert S Tepper; Robert S Wise; Ronina Covar; Charles G Irvin; Carolyn M Kercsmar; Monica Kraft; Mark C Liu; George T O'Connor; Stephen P Peters; Ronald Sorkness; Alkis Togias Journal: J Allergy Clin Immunol Date: 2012-03 Impact factor: 10.793
Authors: Ann Chen Wu; Martin Gregory; Steven Kymes; Dennis Lambert; Joshua Edler; Dustin Stwalley; Anne L Fuhlbrigge Journal: J Allergy Clin Immunol Date: 2012-09-27 Impact factor: 10.793
Authors: Angela J Rogers; Kelan G Tantisira; Anne L Fuhlbrigge; Augusto A Litonjua; Jessica A Lasky-Su; Stanley J Szefler; Robert C Strunk; Robert S Zeiger; Scott T Weiss Journal: Pharmacogenomics Date: 2009-08 Impact factor: 2.533
Authors: Sunita Sharma; Benjamin A Raby; Gary M Hunninghake; Manuel Soto-Quirós; Lydiana Avila; Amy J Murphy; Jessica Lasky-Su; Barbara J Klanderman; Jody S Sylvia; Scott T Weiss; Juan C Celedón Journal: Am J Respir Crit Care Med Date: 2008-12-18 Impact factor: 21.405
Authors: David R Naimi; Tovia G Freedman; Kenneth R Ginsburg; Daniel Bogen; Cynthia S Rand; Andrea J Apter Journal: J Allergy Clin Immunol Date: 2009-04-22 Impact factor: 10.793