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Biomedical subjects

Robert C Strunk

Publications and source records attributed to Robert C Strunk.

At least 19 recordsLinked to original sources

Long-term comparison of 3 controller regimens for mild-moderate persistent childhood asthma: the Pediatric Asthma Controller Trial.

BACKGROUND: More evidence is needed on which to base recommendations for treatment of mild-moderate persistent asthma in school-aged children. OBJECTIVE: The Pediatric Asthma Controller Trial (PACT) compared the effectiveness of 3 regimens in achieving asthma control. METHODS: A total of 285 children (ages 6-14 years) with mild-moderate persistent asthma on the basis of symptoms, and with FEV(1) >or= 80% predicted and methacholine FEV(1) PC(20) or= 80% predicted, confirming current guideline recommendations.

Acetates↗

Childhood Asthma Management Program: lessons learned.

The National Heart, Lung, and Blood Institute Childhood Asthma Management Program was initiated in 1991 and is now the largest and most comprehensive study of long-term intervention with anti-inflammatory therapy in children with mild to moderate asthma. The purpose of this perspective is to review key findings of the study and lessons learned in conducting research in more than 1000 children with persistent asthma for more than 10 years. A key lesson was absence of a continued effect of inhaled corticosteroid on lung growth during long-term follow-up even as symptoms and airway responsiveness remained improved.

Anti-Inflammatory Agents↗

Asthma coaching in the pediatric emergency department.

OBJECTIVES: Coaching and monetary incentives have been used to modify medical behavior of individuals with several chronic diseases, including asthma. The authors performed a randomized, controlled trial of an intervention combining asthma coaching during an emergency department (ED) visit for asthma, and monetary incentive to improve follow-up with primary care providers (PCP). METHODS: Subjects were parents of children 2-12 years of age, with Medicaid or no medical insurance, receiving treatment for asthma in the ED. The primary outcome was a verified PCP visit for asthma within two weeks of the index ED visit. All parents received 15 dollars for their time in the ED. Parents in the intervention group were told that they would receive an additional 15 dollars monetary incentive if a PCP visit was completed. The coach engaged in a dialogue with the parent during the ED visit, and discussed the importance and advantages of seeking follow-up care with the child's PCP. All parents received the usual discharge instructions, including advice to see the PCP within three days. RESULTS: The authors enrolled 92 parents; outcome data were available for 86 (42 controls, 50 intervention). Demographic characteristics were similar in both groups. There was no significant difference in the proportion of patients who had follow-up PCP visits between the intervention (22.0%; 95% confidence interval [95% CI] = 11.5% to 36.0%) and control (23.8%; 95% CI = 12.0% to 39.4%) groups (p = 0.99). CONCLUSIONS: An intervention combining asthma coaching during acute ED visits and a monetary incentive to return for a PCP visit does not appear to increase follow-up with the PCP.

Adult↗

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.).

Administration, Inhalation↗

Asthma is associated with acute chest syndrome and pain in children with sickle cell anemia.

Pain and acute chest syndrome (ACS) episodes are 2 of the most common causes of hospitalization in children with sickle cell anemia (SCA). However, very few potentially modifiable risk factors for either condition have been identified. In this prospective infant cohort study, we tested the hypothesis that asthma is associated with an increased incidence rate of pain and ACS episodes. An infant cohort was composed of 291 African American children with hemoglobin SS enrolled in the Cooperative Study for Sickle Cell Disease before age 6 months and followed beyond age 5 years. Asthma was defined by a physician diagnosis, an acute asthma event, or use of prescription asthma medications. The incidence rates of ACS and painful episodes were compared for children with and without asthma. A clinical diagnosis of asthma was made in 17% of the cohort. Asthma was associated with more frequent ACS episodes (0.39 vs 0.20 events per patient year, P < .001) and painful episodes (1.39 vs 0.47 events per patient year, P < .001). In conclusion, in children with SCA, asthma is associated with an increased incidence of sickle cell disease-related morbidity, including ACS and painful episodes.

Adolescent↗

Bronchodilation and bronchoconstriction: predictors of future lung function in childhood asthma.

BACKGROUND: Persistently low levels of lung function are associated with subsequent symptoms in patients with asthma as children. OBJECTIVES: We hypothesized that objective measures of baseline pulmonary function would be independently associated with future lung function in the Childhood Asthma Management Program and that these associations might vary with treatment. METHODS: We evaluated the association of FEV1, airway responsiveness, and bronchodilator response at randomization as predictors of longitudinal growth in FEV1 at the 48-month follow-up visit in the 1041 Childhood Asthma Management Program participants. RESULTS: Baseline levels of airway responsiveness and bronchodilator response were significantly associated with baseline level of lung function. In multivariate models, higher bronchodilator response (beta = 0.22; P < .0001), log PC20 (beta = 1.82; P < .0001), and FEV1 (beta = 0.58; P < .0001) at randomization were each associated with higher levels of prebronchodilator FEV1, as a percent of predicted, after 4 years. Similar associations were noted for prebronchodilator forced vital capacity and FEV1/forced vital capacity ratio. Baseline bronchodilator response was a particularly powerful predictor of lung function improvements while on inhaled corticosteroids, whereas airway responsiveness was a better predictor in subjects not randomized to any controller medications. CONCLUSION: We conclude that baseline bronchodilator response, airway responsiveness, and level of FEV1 are independent predictors of subsequent level of FEV1 in childhood asthma and may have treatment-specific prognostic significance for persistence of symptoms into early adulthood. CLINICAL IMPLICATIONS: In asthma, bronchodilator and bronchoconstrictor responses are independent predictors of future lung function and should not be used interchangeably; bronchodilator response may indicate good response to inhaled corticosteroids.

Asthma↗

Response profiles to fluticasone and montelukast in mild-to-moderate persistent childhood asthma.

BACKGROUND: Outcome data are needed to base recommendations for controller asthma medication use in school-aged children. OBJECTIVE: We sought to determine intraindividual and interindividual response profiles and predictors of response to an inhaled corticosteroid (ICS) and a leukotriene receptor antagonist (LTRA). METHODS: An ICS, fluticasone propionate (100 mug twice daily), and an LTRA, montelukast (5-10 mg nightly, age dependent), were administered to children ages 6 to 17 years with mild-to-moderate persistent asthma using only as-needed bronchodilators in a multicenter, double-masked, 2-sequence, 16-week crossover trial. Clinical, pulmonary, and inflammatory responses to these controllers were evaluated. RESULTS: Improvements in most clinical asthma control measures occurred with both controllers. However, clinical outcomes (asthma control days [ACDs], the validated Asthma Control Questionnaire, and albuterol use), pulmonary responses (FEV(1)/forced vital capacity, peak expiratory flow variability, morning peak expiratory flow, and measures of impedance), and inflammatory biomarkers (exhaled nitric oxide [eNO]) improved significantly more with fluticasone than with montelukast treatment. eNO was both a predictor of ACDs (P = .011) and a response indicator (P = .003) in discriminating the difference in ACD response between fluticasone and montelukast. CONCLUSIONS: The more favorable clinical, pulmonary, and inflammatory responses to an ICS than to an LTRA provide pediatric-based group evidence to support ICSs as the preferred first-line therapy for mild-to-moderate persistent asthma in children. eNO, as a predictor of response, might help to identify individual children not receiving controller medication who achieve a greater improvement in ACDs with an ICS compared with an LTRA.

Acetates↗

Mild to moderate asthma affects lung growth in children and adolescents.

BACKGROUND: The effect of childhood asthma on lung growth is unclear. OBJECTIVE: To show the effect of mild to moderate childhood asthma on lung growth. METHODS: A total of 1041 children with mild to moderate asthma from the Childhood Asthma Management Program (CAMP) were compared with 5415 children without asthma from the Harvard Six Cities Study (H6CS). Sex-age-specific comparisons of lung growth in CAMP with the H6CS were made by using repeated-measures multiple linear regression models. Sex-age-specific percentages of children with asthma with abnormal (<5th percentile of H6CS) pulmonary function values were calculated. RESULTS: In both boys and girls, the ratio of FEV(1) to forced vital capacity (FVC) was significantly lower for children with than without asthma (P < .001), with corresponding increases for children with asthma in FVC (P < .001). FEV(1) was lower for boys with asthma than for boys without asthma (P < .001), but not for girls (P = .14). Percentages of CAMP children with abnormal FEV(1)/FVC ratios increased with age for both sexes (P < .001). The patterns of lung growth for children with asthma compared with children without asthma did not differ among children treated for 4.3 years with budesonide or nedocromil and placebo during the CAMP trial. CONCLUSION: Mild to moderate asthma results in a pattern of airway obstruction that increases in magnitude from age 5 to 18 years. CLINICAL IMPLICATIONS: Periodic spirometry is needed to monitor children with asthma for signs of increasing airway obstruction with appropriate intervention following national guidelines.

Adolescent↗

Symptom perception in childhood asthma: the role of anxiety and asthma severity.

This study tested the relationship of anxiety and asthma severity to symptom perception. Eighty-six children diagnosed with mild or moderate asthma had symptom perception and pulmonary function measured throughout methacholine challenge (to induce bronchoconstriction). Higher trait anxiety was associated with heightened symptom perception (controlling for pulmonary function) at baseline. Greater asthma severity was associated with blunted symptom perception (controlling for pulmonary function) at the end of methacholine challenge and with a slower rate of increase in symptom perception across methacholine challenge. These results suggest that anxiety plays a role when children's symptoms are mild, whereas medical variables such as severity play a role in perception of changes in asthma symptomatology as bronchoconstriction worsens.

Adolescent↗

Characterization of within-subject responses to fluticasone and montelukast in childhood asthma.

BACKGROUND: Responses to inhaled corticosteroids (ICSs) and leukotriene receptor antagonists (LTRAs) vary among asthmatic patients. OBJECTIVE: We sought to determine whether responses to ICSs and LTRAs are concordant for individuals or whether asthmatic patients who do not respond to one medication respond to the other. METHODS: Children 6 to 17 years of age with mild-to-moderate persistent asthma were randomized to one of 2 crossover sequences, including 8 weeks of an ICS, fluticasone propionate (100 microg twice daily), and 8 weeks of an LTRA, montelukast (5-10 mg nightly depending on age), in a multicenter, double-masked, 18-week trial. Response was assessed on the basis of improvement in FEV 1 and assessed for relationships to baseline asthma phenotype-associated biomarkers. RESULTS: Defining response as improvement in FEV 1 of 7.5% or greater, 17% of 126 participants responded to both medications, 23% responded to fluticasone alone, 5% responded to montelukast alone, and 55% responded to neither medication. Compared with those who responded to neither medication, favorable response to fluticasone alone was associated with higher levels of exhaled nitric oxide, total eosinophil counts, levels of serum IgE, and levels of serum eosinophil cationic protein and lower levels of methacholine PC(20) and pulmonary function; favorable response to montelukast alone was associated with younger age and shorter disease duration. Greater differential response to fluticasone over montelukast was associated with higher bronchodilator use, bronchodilator response, exhaled nitric oxide levels, and eosinophil cationic protein levels and lower methacholine PC(20) and pulmonary function values. CONCLUSIONS: Response to fluticasone and montelukast vary considerably. Children with low pulmonary function or high levels of markers associated with allergic inflammation should receive ICS therapy. Other children could receive either ICSs or LTRAs.

Acetates↗

Refinement of an instrument to evaluate parental attitudes about follow-up care after an acute emergency department visit for asthma.

INTRODUCTION: Prompt follow-up after emergency department (ED) care for asthma allows the primary care provider (PCP) and family to review factors that led to the ED visit, update current care plans, and plan for prevention of future exacerbations. METHODS: The Initial Questionnaire to assess parental impressions of Pros and Cons of follow-up was administered to parents who brought their children to the ED for treatment of an acute asthma exacerbation (N = 309). After a planned interim analysis, 19 new items were generated, and this Expanded Questionnaire was given to 198 parents. Principal Component Analysis (PCA) was used to identify well-defined items and discard ambiguous and confusing items. RESULTS: PCA of the Expanded Questionnaire revealed 18 of 43 items related to four dimensions of parents' Pros and Cons for obtaining follow-up care. Four distinct categories were identified: two Pros and two Cons. Pro items related to practical things parents get from a follow-up visit and to positive parental beliefs about follow-up care. Con items emphasized practical considerations that make it difficult to go to a follow-up visit and identified the misconception that follow-up is not necessary for asymptomatic children. In addition, two distinct clusters of parents were identified: those that value and those that do not value follow-up care. CONCLUSION: We developed an 18-item measure that assesses Pros and Cons of follow-up care for asthma following emergency care, which has four reliable factors: Pro Practical, Pro Attitude, Con Practical, and Con Attitude. This questionnaire may help guide interventions to change perceptions of the need for follow-up. Attention to increasing Pros among those who are reluctant to attend follow-up care may be especially effective.

Acute Disease↗

Association of hypothalamic-pituitary-adrenal axis function with neuropsychological performance in children with mild/moderate asthma.

The present study examines the relationship between hypothalamic-pituitary-adrenal (HPA) axis function and child psychological/neuropsychological function in a group of children with mild to moderate asthma. The goal of the study was to determine whether child neuropsychological functioning and psychological functioning were associated with cortisol production in response to adrenocorticotropic hormone(ACTH) stimulation when assessed as area under the curve. Data for this study were gathered from 63 children who participated in an ancillary study within the Childhood Asthma Management Program (CAMP) during the pre-randomization phase of the CAMP trial. At 2 of the 8 CAMP clinical centers participants completed an ACTH stimulation test after an overnight stay in the General Clinical Research Center. Gender differences on baseline cortisol and change in cortisol 30 minutes after infusion of ACTH were present. Results further indicated significant associations between cortisol production and measures of child neuropsychological function. Stepwise multiple regression analysis revealed that cortisol change could be predicted by measures of gender, working memory, and arousal maintenance, providing support for the hypothesis that cortisol plays a modest role in the neuropsychological function of children with mild and moderate asthma. In contrast, cortisol production was not associated with child reports of psychological functioning. Limitations to the methods employed in this study are discussed.

Adrenocorticotropic Hormone↗

Community Asthma Program improves appropriate prescribing in moderate to severe asthma.

Asthma guidelines, established by the National Asthma Education and Prevention Panel (NAEPP), seek to guide physicians in the appropriate assessment and treatment of asthma. Poor physician adherence to these guidelines has been documented because of a variety of reported barriers. We sought to test the efficacy of the Community Asthma Program (CAP), which was designed to help primary care physicians (PCP) assess asthma severity and to prescribe medications according to NAEPP guidelines. A prospective, observational study was conducted in 723 patients with asthma (aged < 1-85 years) in two primary care clinics. PCPs had access to patient responses to asthma symptom questions at each visit. The correlations between patient self-reported and PCP-classified asthma severity, treatment prescribed, and missed days from work or school were determined. The effect of the intervention on guideline adherence was assessed by asthma severity level and time. An overall moderate measure of agreement was found between patient self-reported and PCP-classified asthma severity (kappa = 0.48; p < 0.001) although this agreement decreased with increasing severity of asthma. Patient self-reported (r = 0.14; p < 0.001) and PCP-classified (r = 0.17; p < 0.001) asthma severity was weakly correlated with missed days from work or school. Those with severe persistent asthma were 89% less likely to be appropriately treated than the mild intermittent group (OR = 0.11; 95% CI-0.1-0.2). This relationship was not influenced by the different clinics or providers nor by the age of the patient. Over time, the CAP-trained PCPs were more likely to appropriately prescribe asthma medications for those with moderate to severe asthma (Mantel-Haenszel chi2 = 5.11; p = 0.02). Despite appropriate assessment of asthma severity, physicians are undertreating patients with severe asthma, the group with the highest health care use. Use of the CAP over time aided PCPs in appropriately medicating patients with moderate to severe asthma in accordance with guidelines.

Adolescent↗

Classifying asthma severity in children: mismatch between symptoms, medication use, and lung function.

Current guidelines for asthma care categorize asthma severity based on the frequency of asthma symptoms, medication use, and lung function measures. The objective of this study was to determine whether lung function measures are consistent with levels of asthma severity as defined by the National Asthma Education and Prevention Program/Expert Panel Report 2 Guidelines. Parents of children aged 5-18 years with asthma seen in two outpatient subspecialty clinics completed questionnaires regarding asthma medication use and symptom frequency over the preceding 1 and 4 weeks, respectively. All children performed spirometry. When asthma severity was based on the higher severity of asthma symptom frequency or medication use, asthma was mild intermittent in 6.9% of participants, mild persistent in 27.9%, moderate persistent in 22.4%, and severe persistent in 42.9%. FEV(1) % predicted did not differ by level of asthma severity. FEV(1)/FVC decreased as asthma severity increased (p < 0.0001) and was abnormal in 33% of the participants, and a greater percentage of participants had an abnormal FEV(1)/FVC as asthma severity increased (p = 0.0001). In children, asthma severity classified by symptom frequency and medication usage does not correlate with FEV(1) categories defined by National Asthma Education and Prevention Program Guidelines. FEV(1) is generally normal, even in severe persistent childhood asthma, whereas FEV(1)/FVC declines as asthma severity increases.

Adolescent↗