Prematurity and respiratory outcomes program (PROP): study protocol of a prospective multicenter study of respiratory outcomes of preterm infants in the United States.

BACKGROUND: With improved survival rates, short- and long-term respiratory complications of premature birth are increasing, adding significantly to financial and health burdens in the United States. In response, in May 2010, the National Institutes of Health (NIH) and the National Heart, Lung, and Blood Institute (NHLBI) funded a 5-year $18.5 million research initiative to ultimately improve strategies for managing the respiratory complications of preterm and low birth weight infants. Using a collaborative, multi-disciplinary structure, the resulting Prematurity and Respiratory Outcomes Program (PROP) seeks to understand factors that correlate with future risk for respiratory morbidity. METHODS/DESIGN: The PROP is an observational prospective cohort study performed by a consortium of six clinical centers (incorporating tertiary neonatal intensive care units [NICU] at 13 sites) and a data-coordinating center working in collaboration with the NHLBI. Each clinical center contributes subjects to the study, enrolling infants with gestational ages 23 0/7 to 28 6/7 weeks with an anticipated target of 750 survivors at 36 weeks post-menstrual age. In addition, each center brings specific areas of scientific focus to the Program. The primary study hypothesis is that in survivors of extreme prematurity specific biologic, physiologic and clinical data predicts respiratory morbidity between discharge and 1 year corrected age. Analytic statistical methodology includes model-based and non-model-based analyses, descriptive analyses and generalized linear mixed models. DISCUSSION: PROP incorporates aspects of NICU care to develop objective biomarkers and outcome measures of respiratory morbidity in the <29 week gestation population beyond just the NICU hospitalization, thereby leading to novel understanding of the nature and natural history of neonatal lung disease and of potential mechanistic and therapeutic targets in at-risk subjects. TRIAL REGISTRATION: Clinical Trials.gov NCT01435187.

Daily or intermittent budesonide in preschool children with recurrent wheezing.

BACKGROUND: Daily inhaled glucocorticoids are recommended for young children at risk for asthma exacerbations, as indicated by a positive value on the modified asthma predictive index (API) and an exacerbation in the preceding year, but concern remains about daily adherence and effects on growth. We compared daily therapy with intermittent therapy. METHODS: We studied 278 children between the ages of 12 and 53 months who had positive values on the modified API, recurrent wheezing episodes, and at least one exacerbation in the previous year but a low degree of impairment. Children were randomly assigned to receive a budesonide inhalation suspension for 1 year as either an intermittent high-dose regimen (1 mg twice daily for 7 days, starting early during a predefined respiratory tract illness) or a daily low-dose regimen (0.5 mg nightly) with corresponding placebos. The primary outcome was the frequency of exacerbations requiring oral glucocorticoid therapy. RESULTS: The daily regimen of budesonide did not differ significantly from the intermittent regimen with respect to the frequency of exacerbations, with a rate per patient-year for the daily regimen of 0.97 (95% confidence interval [CI], 0.76 to 1.22) versus a rate of 0.95 (95% CI, 0.75 to 1.20) for the intermittent regimen (relative rate in the intermittent-regimen group, 0.99; 95% CI, 0.71 to 1.35; P=0.60). There were also no significant between-group differences in several other measures of asthma severity, including the time to the first exacerbation, or adverse events. The mean exposure to budesonide was 104 mg less with the intermittent regimen than with the daily regimen. CONCLUSIONS: A daily low-dose regimen of budesonide was not superior to an intermittent high-dose regimen in reducing asthma exacerbations. Daily administration led to greater exposure to the drug at 1 year. (Funded by the National Heart, Lung, and Blood Institute and others; MIST ClinicalTrials.gov number, NCT00675584.).

Step-up therapy for children with uncontrolled asthma receiving inhaled corticosteroids.

BACKGROUND: For children who have uncontrolled asthma despite the use of low-dose inhaled corticosteroids (ICS), evidence to guide step-up therapy is lacking. METHODS: We randomly assigned 182 children (6 to 17 years of age), who had uncontrolled asthma while receiving 100 microg of fluticasone twice daily, to receive each of three blinded step-up therapies in random order for 16 weeks: 250 microg of fluticasone twice daily (ICS step-up), 100 microg of fluticasone plus 50 microg of a long-acting beta-agonist twice daily (LABA step-up), or 100 microg of fluticasone twice daily plus 5 or 10 mg of a leukotriene-receptor antagonist daily (LTRA step-up). We used a triple-crossover design and a composite of three outcomes (exacerbations, asthma-control days, and the forced expiratory volume in 1 second) to determine whether the frequency of a differential response to the step-up regimens was more than 25%. RESULTS: A differential response occurred in 161 of 165 patients who were evaluated (P<0.001). The response to LABA step-up therapy was most likely to be the best response, as compared with responses to LTRA step-up (relative probability, 1.6; 95% confidence interval [CI], 1.1 to 2.3; P=0.004) and ICS step-up (relative probability, 1.7; 95% CI, 1.2 to 2.4; P=0.002). Higher scores on the Asthma Control Test before randomization (indicating better control at baseline) predicted a better response to LABA step-up (P=0.009). White race predicted a better response to LABA step-up, whereas black patients were least likely to have a best response to LTRA step-up (P=0.005). CONCLUSIONS: Nearly all the children had a differential response to each step-up therapy. LABA step-up was significantly more likely to provide the best response than either ICS or LTRA step-up. However, many children had a best response to ICS or LTRA step-up therapy, highlighting the need to regularly monitor and appropriately adjust each child's asthma therapy. (ClinicalTrials.gov number, NCT00395304.)

Growth of preschool children at high risk for asthma 2 years after discontinuation of fluticasone.

BACKGROUND: The effect on linear growth of daily long-term inhaled corticosteroid therapy in preschool-aged children with recurrent wheezing is controversial. OBJECTIVE: We sought to determine the effect of daily inhaled corticosteroid given for 2 years on linear growth in preschool children with recurrent wheezing. METHODS: Children aged 2 and 3 years with recurrent wheezing and positive modified Asthma Predictive Index scores were randomized to a 2-year treatment period of chlorofluorocarbon-delivered fluticasone propionate (176 µg/d) or masked placebo delivered through a valved chamber with a mask and then followed for 2 years off study medication. Height growth determined by means of stadiometry was compared between treatment groups. RESULTS: In the study cohort as a whole, the fluticasone group did not have significantly less linear growth than the placebo group (change in height from baseline difference, -0.2 cm; 95% CI, -1.1 to 0.6) 2 years after discontinuation of study treatment. In post hoc analyses children 2 years old who weighed less than 15 kg at enrollment and were treated with fluticasone had less linear growth compared with those treated with placebo (change in height from baseline difference, -1.6 cm; 95% CI, -2.8 to -0.4; P = .009). CONCLUSION: Linear growth was not significantly different in high-risk preschool-aged children with recurrent wheezing treated with 176 µg/d chlorofluorocarbon-delivered fluticasone compared with placebo 2 years after fluticasone is discontinued. However, post hoc subgroup analyses revealed that children who are younger in age and of lesser weight relative to the entire study cohort had significantly less linear growth, possibly because of a higher relative fluticasone exposure.

Most nocturnal asthma symptoms occur outside of exacerbations and associate with morbidity.

BACKGROUND: Although nocturnal awakenings help categorize asthma severity and control, their clinical significance has not been thoroughly studied. OBJECTIVE: We sought to determine the clinical consequences of nocturnal asthma symptoms requiring albuterol (NASRAs) in children with mild-to-moderate persistent asthma outside of periods when oral corticosteroids were used for worsening asthma symptoms. METHODS: Two hundred eighty-five children aged 6 to 14 years with mild-to-moderate persistent asthma were randomized to receive one of 3 controller regimens and completed daily symptom diaries for 48 weeks. Diary responses were analyzed for the frequency and consequences of NASRAs. RESULTS: NASRAs occurred in 72.2% of participants at least once, and in 24.3% of participants, they occurred 13 or more times. The majority (81.3%) of nocturnal symptoms occurred outside of exacerbation periods and were associated the next day with the following events: albuterol use (56.9% of days preceded by nocturnal symptoms vs 18.1% of days not preceded by nocturnal symptoms; relative risk [RR], 2.3; 95% CI, 2.2-2.4), school absence (5.0% vs 0.3%; RR, 10.6; 95% CI, 7.8-14.4), and doctor contact (3.7% vs 0.2%; RR, 8.8; 95% CI, 6.1-12.5). Similar findings were noted during exacerbation periods (RRs of 1.7 for albuterol use, 5.5 for school absence, and 4.9 for doctor contacts). Nocturnal symptoms did not predict the onset of exacerbations. CONCLUSION: Nocturnal symptoms requiring albuterol in children with mild-to-moderate persistent asthma receiving controller therapy occurred predominantly outside of exacerbation periods. Despite being poor predictors of exacerbations, they were associated with increases in albuterol use, school absences, and doctor contacts the day after nocturnal symptom occurrences.

Cost-effectiveness analysis of fluticasone versus montelukast in children with mild-to-moderate persistent asthma in the Pediatric Asthma Controller Trial.

BACKGROUND: Cost-effectiveness analyses of asthma controller regimens for adults exist, but similar evaluations exclusively for children are few. OBJECTIVE: We sought to compare the cost-effectiveness of 2 commonly used asthma controllers, fluticasone and montelukast, with data from the Pediatric Asthma Controller Trial. METHODS: We compared the cost-effectiveness of low-dose fluticasone with that of montelukast in a randomized, controlled, multicenter clinical trial in children with mild-to-moderate persistent asthma. Analyses were also conducted on subgroups based on phenotypic factors. Effectiveness measures included (1) the number of asthma-control days, (2) the percentage of participants with an increase over baseline of FEV(1) of 12% or greater, and (3) the number of exacerbations avoided. Costs were analyzed from both a US health care payer's perspective and a societal perspective. RESULTS: For all cost-effectiveness measures studied, fluticasone cost less and was more effective than montelukast. For example, fluticasone treatment cost $430 less in mean direct cost (P < .01) and resulted in 40 more asthma-control days (P < .01) during the 48-week study period. Considering sampling uncertainty, fluticasone cost less and was more effective at least 95% of the time. For the high exhaled nitric oxide (eNO) phenotypic subgroup (eNO ≥25 ppb) and more responsive PC(20) subgroup (PC(20) <2 mg/mL), fluticasone was cost-effective compared with montelukast for all cost-effectiveness measures, whereas not all the effectiveness measures were statistically different for the other 2 phenotypic subgroups. CONCLUSION: For children with mild-to-moderate persistent asthma, low-dose fluticasone had lower cost and higher effectiveness compared with montelukast, especially in those with more airway inflammation, as indicated by increased levels of eNO and more responsivity to methacholine.

Relationship between infant weight gain and later asthma.

Like obesity, the prevalence of asthma has increased over the past several decades. Accelerated patterns of infant growth have been associated with obesity and its co-morbidities. We aimed to determine if infant weight gain pattern is associated with asthma development later in childhood. Birth weight, growth, pulmonary function, and symptom data were collected in a trial of 2- to 3-yr-old children at-risk for asthma randomized to a 2-yr treatment with inhaled corticosteroids or placebo followed by a 1-yr observation period of study medication. Patterns of infant weight gain between birth and study enrollment were categorized as accelerated, average, or decelerated. Regression analyses were used to test the effects of infant weight gain pattern prior to study enrollment on outcomes during the observation year and at study conclusion while adjusting for demographics, baseline symptom severity, study treatment, and atopic indicators. Among the 197 study participants, early life weight gain pattern was not associated with daily asthma symptoms or lung function at the study's conclusion. However, both prednisone courses (p = 0.01) and urgent physician visits (p < 0.001) were significantly associated with weight gain pattern with fewer exacerbations occurring amongst those with a decelerated weight gain pattern. We conclude that early life patterns of weight change were associated with subsequent asthma exacerbations, but were not associated with asthma symptoms or pulmonary function during the pre-school years for these children at-risk for asthma.

Phenotypic predictors of long-term response to inhaled corticosteroid and leukotriene modifier therapies in pediatric asthma.

BACKGROUND: In children with mild-to-moderate persistent asthma, identification of phenotypic predictors to guide selection of a controller regimen is essential. OBJECTIVE: We sought to identify phenotypic characteristics having predictive value for the difference in treatment responses between twice-daily fluticasone and once-daily montelukast. METHODS: Data from the Pediatric Asthma Controller Trial were assessed with multivariate analysis. Outcomes included the change in asthma control days (ACDs), FEV(1), peak expiratory flow, and time to first asthma exacerbation measured over a 1-year treatment period. RESULTS: The mean age was 9.6 +/- 2.1 years, 60% were male, 50% had a parental history of asthma, and 78% had positive aeroallergen skin prick test responses. The mean percent predicted prebronchodilator FEV(1) was 97.8% +/- 12.9%, the median PC(20) value was 0.93 mg/mL, and the median exhaled nitric oxide (eNO) level was 25.2 ppb. A history of parental asthma best predicted the expected treatment benefit with fluticasone compared with montelukast in terms of gain in ACDs (adjusted P = .02) and time to first exacerbation (adjusted P = .05). Increased baseline eNO levels predicted the differential treatment response for fluticasone regarding the gain in ACDs (adjusted P = .01). Prior inhaled corticosteroid (ICS) use (adjusted P = .01) and low PC(20) values (adjusted P = .03) each predicted the expected treatment benefit with fluticasone over montelukast regarding time to first exacerbation. No phenotypic characteristics predicted treatment benefits for montelukast over fluticasone for either outcome. CONCLUSIONS: Physicians treating children with a parental history of asthma, increased eNO levels, low PC(20) values, or a history of ICS use can expect the best long-term outcomes with ICS therapy compared with treatment with leukotriene receptor antagonists.

Patient characteristics associated with improved outcomes with use of an inhaled corticosteroid in preschool children at risk for asthma.

BACKGROUND: Maintenance inhaled corticosteroid (ICS) therapy in preschool children with recurrent wheezing at high-risk for development of asthma produces multiple clinical benefits. However, determination of baseline features associated with ICS responsiveness may identify children most likely to benefit from ICS treatment. OBJECTIVE: To determine if demographic and atopic features predict response to ICS in preschool children at high risk for asthma. METHODS: Two years of treatment with an ICS, fluticasone propionate (88 microg twice daily), was compared with matching placebo in a double-masked, randomized, multicenter study of 285 children 2 and 3 years old at high risk for asthma development. Baseline demographic and atopic features were related to clinical outcomes in a post hoc subgroup analysis. RESULTS: Multivariate analysis demonstrated significantly greater improvement with fluticasone than placebo in terms of episode-free days among boys, white subjects, participants with an emergency department (ED) visit or hospitalization within the past year, and those who experienced more symptomatic days at baseline. Children with aeroallergen sensitization experienced greater benefits in terms of oral corticosteroid use, urgent care and ED visits, and use of supplemental controller medications. CONCLUSIONS: More favorable responses to ICS than placebo in high-risk preschool children over a 2-year period were more likely in those with a ED visit or hospitalization for asthma within the past year, children with aeroallergen sensitization, boys, and white subjects.

Impulse oscillometry versus spirometry in a long-term study of controller therapy for pediatric asthma.

BACKGROUND: Determination of the benefits and limitations of specific physiologic tests has not been well studied in long-term clinical pediatric trials. OBJECTIVE: We sought to determine the utility of impulse oscillometry in a long-term comparison of 3 controller regimens in children with persistent asthma. METHODS: Children 6 to 14 years of age with mild-to-moderate persistent asthma were characterized with oscillometry and spirometry before entry into a clinical trial and then serially during 48 weeks of therapy with either an inhaled corticosteroid, a combination inhaled corticosteroid with a long-acting beta-agonist, or a leukotriene receptor antagonist. RESULTS: The FEV(1)/forced vital capacity ratio, as well as the forced expiratory flow from 25% to 75% of forced vital capacity in terms of spirometric parameters and the reactance area (XA) from impulse oscillometry, appeared to complement information provided by FEV(1) when comparing the tests and factors that appeared to predict a response to treatment. XA was unique in that it, as distinct from spirometric variables, reflected ongoing improvement during the latter part of the trial. In general, improvements in XA during the latter part of the study occurred independently of indices of atopy and the level of airway responsiveness. CONCLUSION: Assessment of respiratory mechanics over time with oscillometry might offer additional insights into the response of asthmatic patients to therapy. In particular, the pattern of improvement seen in XA over the course of therapy suggests this test might detect alterations in airway mechanics not reflected by spirometry. The possibility that changes in XA reflect ongoing improvement in small airway function deserves additional study.

Long-term inhaled corticosteroids in preschool children at high risk for asthma.

BACKGROUND: It is unknown whether inhaled corticosteroids can modify the subsequent development of asthma in preschool children at high risk for asthma. METHODS: We randomly assigned 285 participants two or three years of age with a positive asthma predictive index to treatment with fluticasone propionate (at a dose of 88 mug twice daily) or masked placebo for two years, followed by a one-year period without study medication. The primary outcome was the proportion of episode-free days during the observation year. RESULTS: During the observation year, no significant differences were seen between the two groups in the proportion of episode-free days, the number of exacerbations, or lung function. During the treatment period, as compared with placebo use, use of the inhaled corticosteroid was associated with a greater proportion of episode-free days (P=0.006) and a lower rate of exacerbations (P<0.001) and of supplementary use of controller medication (P<0.001). In the inhaled-corticosteroid group, as compared with the placebo group, the mean increase in height was 1.1 cm less at 24 months (P<0.001), but by the end of the trial, the height increase was 0.7 cm less (P=0.008). During treatment, the inhaled corticosteroid reduced symptoms and exacerbations but slowed growth, albeit temporarily and not progressively. CONCLUSIONS: In preschool children at high risk for asthma, two years of inhaled-corticosteroid therapy did not change the development of asthma symptoms or lung function during a third, treatment-free year. These findings do not provide support for a subsequent disease-modifying effect of inhaled corticosteroids after the treatment is discontinued. (ClinicalTrials.gov number, NCT00272441.).

Signs and symptoms that precede wheezing in children with a pattern of moderate-to-severe intermittent wheezing.

OBJECTIVES: To examine parent-reported signs and symptoms as antecedents of wheezing in preschool children with previous moderate to severe wheezing episodes, and to determine the predictive capacity of these symptom patterns for wheezing events. STUDY DESIGN: Parents (n = 238) of children age 12 to 59 months with moderate-to-severe intermittent wheezing enrolled in a year-long clinical trial completed surveys that captured signs and symptoms at the start of a respiratory tract illness (RTI). Sensitivity, specificity, negative predictive value, and positive predictive value (PPV) for each symptom leading to wheezing during that RTI were calculated. RESULTS: The most commonly reported first symptom categories during the first RTI were "nose symptoms" (41%), "significant cough" (29%), and "insignificant cough" (13%). The most reliable predictor of subsequent wheezing was significant cough, which had a specificity of 78% and a PPV of 74% for predicting wheezing. CONCLUSIONS: Significant cough is the most reliable antecedent of wheezing during an RTI. It may be useful to consider individualized symptom patterns as a component of management plans intended to minimize wheezing episodes.

Factors associated with asthma exacerbations during a long-term clinical trial of controller medications in children.

BACKGROUND: Asthma exacerbations are a common cause of critical illness in children. OBJECTIVE: To determine factors associated with exacerbations in children with persistent asthma. METHODS: Regression modeling was used to identify historical, phenotypic, treatment, and time-dependent factors associated with the occurrence of exacerbations, defined by need for oral corticosteroids or emergency or hospital care in the 48-week Pediatric Asthma Controller Trial study. Children age 6 to 14 years with mild-to-moderate persistent asthma were randomized to receive either fluticasone propionate 100 microg twice daily (FP monotherapy), combination fluticasone 100 microg AM and salmeterol twice daily, or montelukast 5 mg once daily. RESULTS: Of the 285 participants randomized, 48% had 231 exacerbations. Using a multivariate analysis, which included numerous demographic, pulmonary, and inflammatory parameters, only a history of an asthma exacerbation requiring a systemic corticosteroid in the past year (odds ratio [OR], 2.10; P < .001) was associated with a subsequent exacerbation during the trial. During the trial, treatment with montelukast versus FP monotherapy (OR, 2.00; P = .005), season (spring, fall, or winter vs summer; P < or = .001), and average seasonal 5% reduction in AM peak expiratory flow (OR, 1.21; P = .01) were each associated with exacerbations. Changes in worsening of symptoms, beta-agonist use, and low peak expiratory flow track together before an exacerbation, but have poor positive predictive value of exacerbation. CONCLUSION: Children with mild-to-moderate persistent asthma with previous exacerbations are more likely to have a repeat exacerbation despite controller treatment. Inhaled corticosteroids are superior to montelukast at modifying the exacerbation risk. Available physiologic measures and biomarkers and diary card tracking are not reliable predictors of asthma exacerbations.

Episodic use of an inhaled corticosteroid or leukotriene receptor antagonist in preschool children with moderate-to-severe intermittent wheezing.

BACKGROUND: Acute wheezing illnesses in preschoolers require better management strategies to reduce morbidity. OBJECTIVES: We sought to examine the effectiveness of episodic use of an inhaled corticosteroid and a leukotriene receptor antagonist in preschoolers with intermittent wheezing. METHODS: In a randomized, double-blind, placebo-controlled 12-month trial, 238 children aged 12 to 59 months with moderate-to-severe intermittent wheezing received 7 days of either budesonide inhalation suspension (1 mg twice daily), montelukast (4 mg daily), or placebo in addition to albuterol with each identified respiratory tract illness (RTI). Proportion of episode-free days (EFDs) during the 12-month trial was the primary outcome. RESULTS: The 3 treatment groups did not differ in proportions of EFDs, with adjusted mean EFDs of 76% (95% CI, 70% to 81%) for budesonide, 73% (95% CI, 66% to 79%) for montelukast, and 74% (95% CI, 65% to 81%) for conventional therapy (P = .66). The 3 groups did not differ in oral corticosteroid use, health care use, quality of life, or linear growth. However, during RTIs, budesonide and montelukast therapy led to modest reductions in trouble breathing (38% [P = .003] and 37% [P = .003], respectively) and interference with activity scores (32% [P = .01] and 40% [P = .001], respectively) that were most evident in those with positive asthma predictive indices. CONCLUSIONS: In preschool children with moderate-to-severe intermittent wheezing, episodic use of either budesonide or montelukast early in RTIs, when added to albuterol, did not increase the proportion of EFDs or decrease oral corticosteroid use over a 12-month period. However, indicators of severity of acute illnesses were reduced, particularly in children with positive asthma predictive indices.

Azithromycin or montelukast as inhaled corticosteroid-sparing agents in moderate-to-severe childhood asthma study.

BACKGROUND: Clinical trials in children with moderate-to-severe persistent asthma are limited. OBJECTIVE: We sought to determine whether azithromycin or montelukast are inhaled corticosteroid sparing. METHODS: The budesonide dose (with salmeterol [50 microg] twice daily) necessary to achieve control was determined in children 6 to 17 years of age with moderate-to-severe persistent asthma. After a budesonide-stable period of 6 weeks, children were randomized in a double-masked, parallel, multicenter study to receive once-nightly azithromycin, montelukast, or matching placebos plus the established controlling dose of budesonide (minimum, 400 microg twice daily) and salmeterol twice daily. Primary outcome was time from randomization to inadequate asthma control after sequential budesonide dose reduction. RESULTS: Of 292 children screened, only 55 were randomized. Inadequate adherence to study medication (n = 80) and improved asthma control under close medical supervision (n = 49) were the major reasons for randomization failure. A futility analysis was requested by the Data Safety Monitoring Board. In data available for analyses, no differences were noted for either treatment compared with placebo in time to inadequate control status (median: azithromycin, 8.4 weeks [95% confidence limit, 4.3-17.3]; montelukast, 13.9 weeks [95% confidence limit, 4.7-20.6]; placebo, 19.1 weeks [95% confidence limit, 11.7-infinity]), with no difference between the groups (log-rank test, P = .49). The futility analysis indicated that even if the planned sample size was reached, the results of this negative study were unlikely to be different, and the trial was prematurely terminated. CONCLUSION: Based on these results, neither azithromycin nor montelukast is likely to be an effective inhaled corticosteroid-sparing alternative in children with moderate-to-severe persistent asthma.

Sex and the lung: Observations, hypotheses, and future directions.

Sex-related differences in a variety of lung diseases in infants and young children are reviewed, including respiratory distress syndrome, and chronic lung disease of prematurity, lower respiratory tract illnesses and wheezing, asthma, diffuse, and interstitial lung diseases, and cystic fibrosis. Differences in anatomy and physiology, such as airway size, airway muscle bulk, airway reactivity, airway tone, and cough reflexes may explain much of these sex differences. Better understanding of sex-related lung differences could help personalize respiratory treatment.

Markers of Differential Response to Inhaled Corticosteroid Treatment Among Children with Mild Persistent Asthma.

BACKGROUND: Inhaled corticosteroids are recommended as first-line therapy for children with mild persistent asthma; however, specific patient characteristics may modify the treatment response. OBJECTIVE: Identify demographic, clinical, and atopic characteristics that may modify the inhaled corticosteroid treatment response among children enrolled in the Treating Children to Prevent Exacerbations of Asthma trial. METHODS: Children aged 6 to 18 years with mild persistent asthma were randomized to 44 weeks of combined, daily, rescue, or placebo treatment. Daily treatment consisted of 40 µg of beclomethasone twice daily. Rescue treatment consisted of 40 µg of beclomethasone accompanying each symptom-driven albuterol actuation. Combined treatment consisted of both. Outcomes included time to first exacerbation and proportion of asthma control days. Fourteen baseline characteristics were selected for interaction testing on the basis of their clinical relevance. RESULTS: Two hundred eighty-eight children were randomized. Seventy-five percent were white, and 55% were male. As measured by time to first exacerbation, 4 characteristics identified children who received greater benefit from treatment: non-Hispanic ethnicity, positive aeroallergen skin test result, serum immunoglobulin E level of 350 K/µL or more, and history of oral corticosteroid use in the year before enrollment. As measured by asthma control days, 4 characteristics identified children who received greater benefit from treatment: male sex, positive aeroallergen skin test result, serum immunoglobulin E level of 350 K/µL or more, and incomplete run-in asthma control. CONCLUSIONS: Children with mild persistent asthma who have markers of atopic asthma or who have greater asthma burden may obtain greater benefit from beclomethasone therapy. Additional study is needed to confirm whether these markers can guide individualized therapy.

Effect of elevated exhaled nitric oxide levels on the risk of respiratory tract illness in preschool-aged children with moderate-to-severe intermittent wheezing.

BACKGROUND: The fractional concentration of exhaled nitric oxide (FeNO) is a noninvasive marker for airway inflammation but requires further study in preschool-aged children to determine its clinical relevance. OBJECTIVE: To determine whether the risk of respiratory tract illnesses (RTIs), disease burden, and atopic features are related to FeNO in preschool-aged children with moderate-to-severe intermittent wheezing. METHODS: We determined FeNO using the off-line tidal breathing technique in 89 children, aged 12 to 59 months, with moderate-to-severe intermittent wheezing. The risk of RTI was determined by comparing participants with a baseline FeNO of greater than the 75th percentile (24.4 ppb) with those with a baseline FeNO at the 75th percentile or lower using Cox regression analysis. RESULTS: The risk of RTI was significantly higher in children with an FeNO of greater than 24.4 ppb relative to those with lower FeNO values (adjusted relative risk, 3.80; 95% confidence interval, 1.74-8.22; P < .001). FeNO levels of greater than 24.4 ppb were associated with more positive skin test results to aeroallergens (P = .03) but not with other atopic characteristics or historic parameters of illness burden. CONCLUSIONS: An elevated FeNO in preschool-aged children with moderate-to-severe intermittent wheezing was associated with an increased risk of RTI during a 1-year follow-up. In addition, a higher FeNO was associated with aeroallergen sensitization.