Does current asthma control predict future health care use among black preschool-aged inner-city children?

Association Between Asthma Control Trajectories in Preschoolers and Long-Term Asthma Control

BACKGROUND

The potential influence of asthma control in early life on long-term outcomes in childhood remains largely unknown.

OBJECTIVE

To examine whether asthma control trajectories in the 2 years after diagnosis in preschoolers are associated with long-term unsatisfactory asthma control.

METHODS

We conducted a multicenter population-based retrospective cohort study, including four Canadian provincial birth cohorts derived from administrative databases. We included preschoolers (aged <5 years) with a diagnosis of asthma, defined as having one hospitalization or two physician visits for asthma within 2 years. Asthma control trajectories, ascertained over four 6-month periods after diagnosis using a validated index, were classified as controlled throughout, improving control, fluctuating control, worsening control, and out of control throughout. Long-term unsatisfactory control was defined as four or more short-acting β₂-agonist average doses per week or an exacerbation, measured within 6 months before index ages 6, 8, 10, 12, 14, and 16 years. Average risk ratios for long-term unsatisfactory control across all index ages were estimated using a robust Poisson model by province and meta-analyzed with a random effects model.

RESULTS

In 50,188 preschoolers with asthma, the pooled average risk of having unsatisfactory control at any index age was 42% (95% confidence interval, 34.6-49.4). Compared with children who were controlled throughout, incrementally higher average risk ratios (95% confidence interval) of long-term unsatisfactory control were observed in each trajectory: improving control, 1.38 (1.28-1.49); fluctuating control, 1.54 (1.40-1.68); worsening control, 1.70 (1.55-1.86) and out of control throughout, 2.00 (1.80-2.21).

CONCLUSIONS

Suboptimal asthma control trajectories shortly after a preschool diagnosis were associated with long-term unsatisfactory asthma control. Early control trajectories appear to be promising for predicting the risk for long-term adverse outcomes.

Considering the Control Group: The Influence of Follow-Up Assessments on Asthma Symptoms

OBJECTIVE

It is unclear whether research participation effects contribute to an improvement in asthma symptoms during clinical trials in the absence of any active intervention. We examined the impact of additional follow-up surveys on caregiver-reported symptoms among control subjects in a series of randomized controlled asthma trials.

METHODS

We analyzed baseline and follow-up data for children (3-10 years) with poorly controlled persistent asthma that participated as control subjects in 1 of 3 randomized trials of urban school-based asthma care (study duration: 7-10 months). We compared mean symptom-free days (SFD) per 2 weeks between baseline and final follow-up; performed bivariate regressions to explore associations between demographics and changes in SFD; and performed multivariate random-effects generalized least square regression to examine the relationship between number of follow-ups beyond baseline (range: 1-10) and changes in SFD over time.

RESULTS

Five hundred and sixteen children were enrolled as controls across the 3 trials (mean age 7.5 years, 61% Black, 28% Hispanic, 81% Medicaid). Mean SFDs increased significantly from baseline to final follow-up (7.8-11.4 days, P < .001). In adjusted analyses, significant improvements in SFD were observed with all follow-up contacts in comparison with baseline. Symptom improvement showed a dose-response relationship with the number of follow-up assessments completed (1, 2-3, 4-5, and 6-10 assessments).

CONCLUSIONS

Children with uncontrolled asthma who participate as controls in clinical trials experience a significant increase in SFD with additional follow-up assessments. This improvement should be considered when designing/analyzing asthma interventions, and may help guide clinical outreach efforts for underserved children with persistent asthma.

Nurse-delivered outpatient asthma education for children and caregivers: a pilot study to promote shared asthma management

OBJECTIVES

To assess the feasibility of nurse-delivered asthma education for caregiver/child dyads in a busy clinic setting, and measure the preliminary effectiveness of the intervention.

METHODS

We conducted a pilot study of nurse-delivered asthma education in a busy outpatient clinic. We enrolled a convenience sample of children (7-16 years) with uncontrolled persistent asthma who had a prescription for an inhaled controller medication and public health insurance. After provider visits, nurses taught dyads using picture-based materials, teach-back methods, and colored labels applied to asthma medications. The intervention was repeated at 1-month follow-up. We assessed feasibility by reviewing nurse documentation in the electronic medical record, detailing whether each component was implemented and the time required for education at each visit. We measured preliminary effectiveness by surveying children and caregivers separately before each clinic visit about asthma management responsibility, self-efficacy, caregiver quality of life, and symptoms; caregivers also completed a final telephone survey 2 months after the follow-up visit. We examined pre-post differences in continuous outcomes within-subjects using Wilcoxon signed rank tests.

RESULTS

We enrolled 22 child/caregiver dyads. Nursing documentation indicated a high rate of component delivery at each visit; the initial and 1-month visits required 25 and 15 min, respectively. We observed significant increases in child responsibility, child/caregiver self-efficacy, caregiver quality of life, and child symptoms at each follow-up.

CONCLUSION

This intervention of patient-centered asthma education can be delivered by nurses to caregiver/child dyads with high fidelity in a busy pediatric practice. Preliminary data indicate potential benefit for both children and caregivers.

Discovering Pediatric Asthma Phenotypes on the Basis of Response to Controller Medication Using Machine Learning

RATIONALE

Pediatric asthma has variable underlying inflammation and symptom control. Approaches to addressing this heterogeneity, such as clustering methods to find phenotypes and predict outcomes, have been investigated. However, clustering based on the relationship between treatment and clinical outcome has not been performed, and machine learning approaches for long-term outcome prediction in pediatric asthma have not been studied in depth.

OBJECTIVES

Our objectives were to use our novel machine learning algorithm, predictor pursuit (PP), to discover pediatric asthma phenotypes on the basis of asthma control in response to controller medications, to predict longitudinal asthma control among children with asthma, and to identify features associated with asthma control within each discovered pediatric phenotype.

METHODS

We applied PP to the Childhood Asthma Management Program study data (n = 1,019) to discover phenotypes on the basis of asthma control between assigned controller therapy groups (budesonide vs. nedocromil). We confirmed PP's ability to discover phenotypes using the Asthma Clinical Research Network/Childhood Asthma Research and Education network data. We next predicted children's asthma control over time and compared PP's performance with that of traditional prediction methods. Last, we identified clinical features most correlated with asthma control in the discovered phenotypes.

RESULTS

Four phenotypes were discovered in both datasets: allergic not obese (A⁺/O^-), obese not allergic (A^-/O⁺), allergic and obese (A⁺/O⁺), and not allergic not obese (A^-/O^-). Of the children with well-controlled asthma in the Childhood Asthma Management Program dataset, we found more nonobese children treated with budesonide than with nedocromil (P = 0.015) and more obese children treated with nedocromil than with budesonide (P = 0.008). Within the obese group, more A⁺/O⁺ children's asthma was well controlled with nedocromil than with budesonide (P = 0.022) or with placebo (P = 0.011). The PP algorithm performed significantly better (P < 0.001) than traditional machine learning algorithms for both short- and long-term asthma control prediction. Asthma control and bronchodilator response were the features most predictive of short-term asthma control, regardless of type of controller medication or phenotype. Bronchodilator response and serum eosinophils were the most predictive features of asthma control, regardless of type of controller medication or phenotype.

CONCLUSIONS

Advanced statistical machine learning approaches can be powerful tools for discovery of phenotypes based on treatment response and can aid in asthma control prediction in complex medical conditions such as asthma.

Caregiver-Reported Asthma Control Predicts Future Visits, Independent of Guideline-Based Control Measures

BACKGROUND

It is unknown whether caregiver perception of a child's asthma control, independent of guideline-based asthma control assessment, is a predictor of future acute visits.

OBJECTIVE

To determine whether caregiver-reported asthma control is an indicator of future risk of acute visit.

METHODS

Two study populations of low-income, minority 5- to 17-year-old children with persistent asthma were included. Questionnaires administered at baseline and at 3, 6, 9, and 12 months captured symptoms, short-acting β-agonist use, acute visits in the previous 3 months, and caregiver-reported asthma control. Well-controlled, not well-controlled, and very poorly controlled asthma were defined using National Asthma Education and Prevention Program guideline-based assessment. Relationships between caregiver-reported control and acute visits in the subsequent 3 months were examined.

RESULTS

At baseline, both populations were predominantly black/African American (91% and 79%) with public insurance (85% and 88%) and very poorly controlled asthma (47% and 50%). In both populations, most caregivers reported that their child's asthma was well controlled (73% and 69%). In both populations, participants whose caregivers reported that their child had uncontrolled asthma had greater odds of having an acute visit in the following 3 months as compared with participants whose caregivers reported that their child's asthma was well controlled, independent of guideline-based control, age, sex, race, controller medication, insurance, and atopy (odds ratio [95% CI], 2.4 [1.4-4.2] and 1.6 [1.1-2.4]).

CONCLUSIONS

Among predominantly low-income minority children with asthma, caregiver-reported asthma control may provide information about the risk of future acute visit for asthma that is complementary to guideline-based control assessment.

Predictive Value of the TRACK Questionnaire as a Measure of Asthma Control in Preschool Aged Children

Assessment of asthma control in preschool children is important for therapeutic decisions. Aim of this study was to evaluate the predictive value of TRACK questionnaire scores for subsequent clinical parameters and to investigate the validity and reliability of the Turkish version of the TRACK questionnaire. We enrolled 100 children with asthma aged 4 years or younger in this cohort study. We recorded sociodemographic characteristics and clinical severity parameters. A pediatric allergist filled in the asthma severity scale and the caregiver of the child filled in the TRACK questionnaire. We called in the children again at the end of one month and recorded the same parameters and administered TRACK again. Uncontrolled asthma was defined as a TRACK score below 80. According to the TRACK score, 65% of the children had controlled asthma initially while at the end of the study 64.1% had controlled asthma. At the beginning of the study, all clinical parameters were worse in children with uncontrolled asthma according to TRACK score. Similarly, other objective clinical parameters during the following one month period were worse in children with initial uncontrolled asthma. Cronbach's alpha score for the TRACK questionnaire was 0.84. Turkish TRACK questionnaire is a valid and reliable tool that is predictive of short term asthma prognosis.

Perceived parent financial burden and asthma outcomes in low-income, urban children

The purpose of this study was to describe the demographic characteristics of low-income parents who perceive financial burden in managing their child's asthma and related associations with their children's asthma outcomes and clinical characteristics. We hypothesized that (1) identifiable differences between parents who do and do not report burden; (2) regardless of access to care, asthma outcomes would be worse for children whose parents perceive financial burden in obtaining care for their child's condition. Baseline data from a randomized trial evaluating the effect of a school-based asthma intervention were analyzed for this research. Eight hundred thirty-five parents were interviewed by telephone regarding their child's asthma management. Associations between demographic and clinical factors and perception of financial burden were examined using bivariate analysis. Multivariate regression analyses were used to examine associations between perceptions of financial burden and asthma outcomes, including emergency department visits, hospitalizations, and missed school days. Perceived financial burden was evident in 10% (n = 79) of parents. Female heads of household (χ2 (3) = 7.41; p < 0.05), those at the lowest income levels (χ2 (3) = 12.14; p < 0.01), and those whose child's asthma was poorly controlled (χ2 (2) = 49.42; p < 0.001) were most likely to perceive financial burden. In models controlling for level of asthma control, income, and having a usual source of asthma care, parents who perceived financial burden were more likely to have children who had at least one emergency department visit (OR = 1.95; 95% CI = 1.15 to 3.29), hospitalization (OR = 3.99; 95% CI = 2.03 to 7.82), or missed school days due to asthma (OR = 3.26; 95% CI = 1.60 to 6.67) in the previous year. Our results supported our hypotheses. Among low-income parents of children with asthma, the majority do not perceive financial burden to obtaining care. However, among parents that do perceive burden, urgent care use and missed school days due to asthma for their child were significantly higher, regardless of family income and having a usual source of asthma care. Mothers and grandmothers heading families and those caring for children with uncontrolled asthma were most likely to report burden. These findings have implications for clinical practice in that health care providers may be able to take simple actions to determine patients' financial-related perceptions, correct misconceptions, and help patients consider their full range of options to manage their child's asthma.

Consistently very poorly controlled asthma, as defined by the impairment domain of the Expert Panel Report 3 guidelines, increases risk for future severe asthma exacerbations in The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens (TENOR) study

BACKGROUND

Identification of patients at risk for asthma exacerbations can assist physicians in addressing disease management and improve asthma-related health outcomes.

OBJECTIVE

We sought to evaluate whether level of impairment, as defined by the 2007 asthma guidelines, predicts risk for future asthma exacerbations.

METHODS

The study included children aged 6 to 11 years (n = 82) and adolescent/adult patients aged 12 years and older (n = 725) from The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens study with data representing all components of the impairment domain of the asthma guidelines at baseline, month 12, and month 24. Patients were categorized into 2 cohorts: (1) consistently very poorly controlled (VPC) asthma from baseline through 2 years of follow-up and (2) improved from VPC asthma at baseline (including patients who improved to not well-controlled or well-controlled asthma), with improvement maintained through 2 years of follow-up. Odds ratios (ORs) and 95% CIs for risk of asthma exacerbations at month 30 were generated by using multivariable logistic regression by age group.

RESULTS

After adjustment, children with consistently VPC asthma over the 2-year period demonstrated a 6-fold increased risk of hospitalization, emergency department visit, or corticosteroid burst (OR, 6.4; 95% CI, 1.2-34.5) compared with the improved group. Adolescent/adult patients with consistently VPC asthma were more likely to have a corticosteroid burst (OR, 2.8; 95% CI, 1.7-4.8) or have a hospitalization, emergency department visit, or corticosteroid burst (OR, 3.2; 95% CI, 1.9-5.3).

CONCLUSIONS

Consistently VPC asthma, as defined by the impairment domain of the 2007 asthma guidelines, is strongly predictive of future asthma exacerbations.

Interventions for educating children who are at risk of asthma-related emergency department attendance

BACKGROUND

Asthma is the most common chronic childhood illness and is a leading cause for paediatric admission to hospital. Asthma management for children results in substantial costs. There is evidence to suggest that hospital admissions could be reduced with effective education for parents and children about asthma and its management.

OBJECTIVES

To conduct a systematic review of the literature and update the previous review as to whether asthma education leads to improved health outcomes in children who have attended the emergency room for asthma.

SEARCH STRATEGY

We searched the Cochrane Airways Group Trials Register, including the MEDLINE, EMBASE and CINAHL databases, and reference lists of trials and review articles (last search May 2008).

SELECTION CRITERIA

We included randomised controlled trials of asthma education for children who had attended the emergency department for asthma, with or without hospitalisation, within the previous 12 months.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data. We contacted study authors for additional information. We pooled dichotomous data with a fixed-effect risk ratio. We used a random-effects risk ratio for sensitivity analysis of heterogenous data.

MAIN RESULTS

A total of 38 studies involving 7843 children were included. Following educational intervention delivered to children, their parents or both, there was a significantly reduced risk of subsequent emergency department visits (RR 0.73, 95% CI 0.65 to 0.81, N = 3008) and hospital admissions (RR 0.79, 95% CI 0.69 to 0.92, N = 4019) compared with control. There were also fewer unscheduled doctor visits (RR 0.68, 95% CI 0.57 to 0.81, N = 1009). Very few data were available for other outcomes (FEV1, PEF, rescue medication use, quality of life or symptoms) and there was no statistically significant difference between education and control.

AUTHORS' CONCLUSIONS

Asthma education aimed at children and their carers who present to the emergency department for acute exacerbations can result in lower risk of future emergency department presentation and hospital admission. There remains uncertainty as to the long-term effect of education on other markers of asthma morbidity such as quality of life, symptoms and lung function. It remains unclear as to what type, duration and intensity of educational packages are the most effective in reducing acute care utilisation.

A longitudinal study of indoor nitrogen dioxide levels and respiratory symptoms in inner-city children with asthma

BACKGROUND

The effect of indoor nitrogen dioxide concentrations on asthma morbidity among inner-city preschool children is uncertain.

OBJECTIVES

Our goal was to estimate the effect of indoor NO2 concentrations on asthma morbidity in an inner-city population while adjusting for other indoor pollutants.

METHODS

We recruited 150 children (2-6 years of age) with physician-diagnosed asthma from inner-city Baltimore, Maryland. Indoor air was monitored over a 72-hr period in the children's bedrooms at baseline and 3 and 6 months. At each visit, the child's caregiver completed a questionnaire assessing asthma symptoms over the previous 2 weeks and recent health care utilization.

RESULTS

Children were 58% male, 91% African American, and 42% from households with annual income < $25,000; 63% had persistent asthma symptoms. The mean (+/- SD) in-home NO2 concentration was 30.0 +/- 33.7 (range, 2.9-394.0) ppb. The presence of a gas stove and the use of a space heater or oven/stove for heat were independently associated with higher NO2 concentrations. Each 20-ppb increase in NO2 exposure was associated significantly with an increase in the number of days with limited speech [incidence rate ratio (IRR) = 1.15; 95% confidence interval (CI), 1.05-1.25], cough (IRR = 1.10; 95% CI, 1.02-1.18), and nocturnal symptoms (IRR = 1.09; 95% CI, 1.02-1.16), after adjustment for potential confounders. NO2 concentrations were not associated with increased health care utilization.

CONCLUSIONS

Higher indoor NO2 concentrations were associated with increased asthma symptoms in preschool inner-city children. Interventions aimed at lowering NO2 concentrations in inner-city homes may reduce asthma morbidity in this vulnerable population.