Asthma update

Delayed acquisition of airway commensals in antibiotic naïve children and its relationship with wheezing in rural Ecuador

Introduction

The hygiene hypothesis identified a relationship between living in rural areas and acquiring protective environmental factors against the development of asthma and atopy. In our previous study, we found a correlation between particular bacterial species and early-onset wheezing in infants from the rural tropics of Ecuador who were corticosteroid-naïve and had limited antibiotic exposure. We now describe a longitudinal study of infants conducted to determine the age-related changes of the microbiome and its relationship with wheezing.

Methods

We performed an amplicon sequencing of the 16S rRNA bacterial gene from the oropharyngeal samples obtained from 110 infants who had a history of recurrent episodic wheezing sampled at different ages (7, 12, and 24 months) and compared it to the sequencing of the oropharyngeal samples from 150 healthy infants sampled at the same time points. Bioinformatic analyses were conducted using QIIME and R.

Results

As expected, the microbiota diversity consistently increased as the infants grew older. Considering age-based microbiota changes, we found that infants with wheeze had significantly lower species richness than the healthy infants at 7 months, but not at 12 or 24 months. Most of the core and accessory organisms increased in abundance and prevalence with age, except for a few which decreased. At 7 months of age, infants with wheeze had notably higher levels of a single Streptococcus operational taxonomic unit and core microbiota member than controls.

Conclusions

In a cohort with limited antibiotic and corticosteroid use, a progressively more complex and diverse respiratory microbial community develops with age. The respiratory microbiota in early life is altered in infants with wheeze, but this does not hold true in older infants.

A Predictive Model for Identification of Children at Risk of Subsequent High-Frequency Utilization of the Emergency Department for Asthma

BACKGROUND

Asthma is the most common chronic condition among children with high-frequency emergency department (ED) utilization. Previous research has shown in outpatients seen for asthma that acute care visits predict subsequent health care utilization. Among ED patients, however, the optimal method of predicting subsequent ED utilization remains to be described. The goal of this study was to create a predictive model to identify children in the ED who are at risk of subsequent high-frequency utilization of the ED for asthma.

METHODS

We used 3 years of data, 2013-2015, drawn from the electronic health records at a tertiary care, urban, children's hospital that is a high-volume center for asthma care. Data were split into a derivation (50%) and validation/test (50%) set, and 3 models were created for testing: (1) all index patients; (2) removing patients with complex chronic conditions; and (3) subset of patients with in-network care on whom more clinical data were available. Each multivariable model was then tested in the validation set, and its performance evaluated by predicting error rate, calculation of a receiver operating characteristic (ROC) curve, and identification of the optimal cutpoint to maximize sensitivity and specificity.

RESULTS

There were 5535 patients with index ED visits, of whom 2767 were in the derivation set and 2768 in the validation set. Of the 5535 patients, 125 patients (2.3%) had 4 or more visits for asthma in the outcome year. Significant predictors in models 1 and 2 were age and number of prior ED visits for asthma. For model 3 (additional clinical information available), the predictors were number of prior ED visits for asthma, number of primary care visits, and not having a controller medication. Areas under the ROC curve were 0.77 for model 1, 0.80 for model 2, and 0.77 for model 3.

CONCLUSIONS

Administrative data available at the time of ED triage can predict subsequent high utilization of the ED, with areas under the ROC curve of 0.77 to 0.80. The addition of clinical variables did not improve the model performance. These models provide useful tools for researchers interested in examining intervention efficacy by predicted risk group.

National estimates of 30-day readmissions among children hospitalized for asthma in the United States

OBJECTIVE

Previous single-center studies have reported that up to 40% of children hospitalized for asthma will be readmitted. The study objectives are to investigate the prevalence and timing of 30-day readmissions in children hospitalized with asthma, and to identify factors associated with 30-day readmissions.

METHODS

Data (n = 12,842) for children aged 6-18 years hospitalized for asthma were obtained from the 2013 Nationwide Readmission Database (NRD). The primary study outcome was time to readmission within 30 days after discharge attributable to any cause. Several predictors associated with the risk of admission were included: patient (age, sex, median household income, insurance type, county location, and pediatric chronic complex condition), admission (type, day, emergency services utilization, length of stay (LOS), and discharge disposition), and hospital (ownership, bed size, and teaching status). Cox's proportional hazards model was used to identify predictors.

RESULTS

Of 12,842 asthma-related index hospitalizations, 2.5% were readmitted within 30-days post-discharge. Time to event models identified significantly higher risk of readmission among asthmatic children aged 12-18 years, those who resided in micropolitan counties, those with >4-days LOS during index hospitalization, those who were hospitalized in an urban hospital, who had unfavorable discharge (hazard ratio 2.53, 95% confidence interval 1.33-4.79), and those who were diagnosed with a pediatric complex chronic condition, respectively, than children in respective referent categories.

CONCLUSION

A multi-dimensional approach including effective asthma discharge action plans and follow-up processes, home-based asthma education, and neighborhood/community-level efforts to address disparities should be integrated into the routine clinical care of asthma children.

Development of a Patient-centered Outcome Measure for Emergency Department Asthma Patients

BACKGROUND

Measuring outcomes of emergency care is of key importance, but current metrics, such as 72-hour return visit rates, are subject to ascertainment bias, incentivize overtesting and overtreatment at initial visit, and do not reflect the full burden of disease and morbidity experienced at home following ED care. There is increasing emphasis on including patient-reported outcomes, but the existing patient-reported measures have limited applicability to emergency care.

OBJECTIVE

The objective was to identify concepts for inclusion in a patient-reported outcome measure for ED care and assess differences in potential concepts by health literacy.

METHODS

A three-phase qualitative study was completed using freelisting and semistructured interviewing for concept identification, member checking for concept ranking, and cognitive interviewing for question development. Participants were drawn from three tertiary care EDs. Parents of patients (pediatric) or patients (adult) with asthma completed a demographic survey and an assessment of health literacy. Phase 1 participants also completed a freelisting exercise and qualitative interview regarding the definition of success following ED discharge. Phase 2 participants completed a member checking survey based on concepts identified in Phase 1. Phase 3 was a pilot of trial questions based on the highest-ranked concepts from Phase 2.

RESULTS

Phase 1 enrolled 22 adult patients and 37 parents of pediatric patients. Phase 2 enrolled 41 adult patients and 200 parents. Phase 3 involved 15 parents. Across all demographic/literacy groups, Phase 1 participants reported return to usual activity and lack of asthma symptoms as the most important markers of success. In Phase 2, symptom improvement, medication use and access, and asthma knowledge were identified as the most important components of the definition of post-ED discharge success. Phase 3 resulted in five questions for the proposed measure.

CONCLUSIONS

A stepwise qualitative process can identify, rank, and formulate questions based on patient-identified concepts for inclusion in a patient-reported outcome measure for ED discharge. The four key concepts identified for inclusion: symptom improvement, medication access, correct medication use, and asthma knowledge are not measured by existing quality metrics.

Paediatric ED BiPAP continuous quality improvement programme with patient analysis: 2005-2013

OBJECTIVE

In paediatric moderate-to-severe asthmatics, there is significant bronchospasm, airway obstruction, air trapping causing severe hyperinflation with more positive intraplural pressure preventing passive air movement. These effects cause an increased respiratory rate (RR), less airflow and shortened inspiratory breath time. In certain asthmatics, aerosols are ineffective due to their inadequate ventilation. Bilevel positive airway pressure (BiPAP) in acute paediatric asthmatics can be an effective treatment. BiPAP works by unloading fatigued inspiratory muscles, a direct bronchodilation effect, offsetting intrinsic PEEP and recruiting collapsed alveoli that reduces the patient's work of breathing and achieves their total lung capacity quicker. Unfortunately, paediatric emergency department (PED) BiPAP is underused and quality analysis is non-existent. A PED BiPAP Continuous Quality Improvement Program (CQIP) from 2005 to 2013 was evaluated using descriptive analytics for the primary outcomes of usage, safety, BiPAP settings, therapeutics and patient disposition.

INTERVENTIONS

PED BiPAP CQIP descriptive analytics.

SETTING

Academic PED.

PARTICIPANTS

1157 patients.

INTERVENTIONS

A PED BiPAP CQIP from 2005 to 2013 for the usage, safety, BiPAP settings, therapeutic response parameters and patient disposition was evaluated using descriptive analytics.

PRIMARY AND SECONDARY OUTCOMES

Safety, usage, compliance, therapeutic response parameters, BiPAP settings and patient disposition.

RESULTS

1157 patients had excellent compliance without complications. Only 6 (0.5%) BiPAP patients were intubated. BiPAP median settings: IPAP 18 (16,20) cm H₂O range 12-28; EPAP 8 cmH₂O (8,8) range 6-10; inspiratory-to-expiratory time (I:E) ratio 1.75 (1.5,1.75). Pediatric Asthma Severity score and RR decreased (p<0.001) while tidal volume increased (p<0.001). Patient disposition: 325 paediatric intensive care units (PICU), 832 wards, with 52 of these PED ward patients were discharged home with only 2 hours of PED BiPAP with no returning to the PED within 72 hours.

CONCLUSIONS

BiPAP is a safe and effective therapeutic option for paediatric patients with asthma presenting to a PED or emergency department. This BiPAP CQIP showed significant patient compliance, no complications, improved therapeutics times, very low intubations and decreased PICU admissions. CQIP analysis demonstrated that using a higher IPAP, low EPAP with longer I:E optimises the patient's BiPAP settings and showed a significant improvement in PAS, RR and tidal volume. BiPAP should be considered as an early treatment in the PED severe or non-responsive moderate asthmatics.

A Cost Analysis of Salbutamol Administration by Metered-Dose Inhalers with Spacers versus Nebulization for Patients with Wheeze in the Pediatric Emergency Department: Evidence from Observational Data in Nova Scotia

BACKGROUND

Despite evidence demonstrating the advantages of metered-dose inhalers with spacers (MDI-s), nebulization (NEB) remains the primary method of asthma treatment in some pediatric emergency departments (PEDs). There is a perception that delivering salbutamol by MDI-s is more costly than by NEB. This research evaluates the relative costs of MDI-s and NEB using local, hospital-specific, patient-level data.

METHODS

Regression models estimated associations between the salbutamol inhalation method and costs, length of stay (LOS) in the PED and hospital, and the probability of admission. Our population was a random sample of 822 patients presenting with wheeze to the PED in 2008/2009. Control variables included age, sex, triage acuity, time of PED visit, other medications, and vitals. Costs were calculated using the prices and quantities of medical resources used per treatment. Probabilistic sensitivity analysis was used.

RESULTS

Treatment with MDI-s versus NEB was associated with an absolute decrease in hospitalization of 4.4% (p<0.05) and a 25-hour (p<0.001) reduction in average inpatient stay, after controlling for triage acuity and patient characteristics. This resulted in savings of $24/patient in the PED and $180/patient overall (p<0.001). Inpatient care accounted for more than 90% of total patient costs.

CONCLUSIONS

Our results suggest economic gains associated with MDI-s for salbutamol inhalation in PEDs. Sensitivity analyses show that this conclusion is not affected by changes in model parameters that may differ by jurisdiction. Since most facilities already collect the data used for this study, our methods could be adopted for a cross-jurisdictional account of the cost effectiveness of MDI-s.

Unmet Needs at the Time of Emergency Department Discharge

OBJECTIVES

Emergency department (ED) discharge requires conveying critical information in a time-limited and distracting setting. Limited health literacy may put patients at risk of incomplete comprehension, but the relationship between discharge communication needs and health literacy has not been well defined. The goal of this study was to characterize the variation in needs and preferences regarding the ED discharge process by health literacy and identify novel ideas for process improvement from parents and patients.

METHODS

This was an in-depth qualitative interview study in two EDs using asthma as a model system for health communication. Adult patients and parents of pediatric patients with an asthma exacerbation and planned discharge were enrolled using purposive sampling to balance across literacy groups at each site. Interviews were audiotaped, transcribed, coded independently by two team members, and analyzed using a modified grounded theory approach. Interviews were conducted until thematic saturation was reached in both literacy groups at each site.

RESULTS

In-depth interviews were completed with 51 participants: 20 adult patients and 31 pediatric parents. The majority of participants identified barriers related to ED providers, such as use of medical terminology, and systems of care, such as absence of protected time for discharge communication. Patients with limited health literacy, but not those with adequate literacy, identified conflicting information between health care sources as a barrier to successful ED discharge.

CONCLUSIONS

Participants across literacy groups and settings identified multiple actionable areas for improvement in the ED discharge process. These included the use of simplified/lay language, increased visual learning and demonstration, and the desire for complete information. Individuals with limited literacy may particularly benefit from increased attention to consistency.

Childhood Asthma Management and Environmental Triggers

Asthma is the most common chronic disease among children. It cannot be prevented but can be controlled. Industrialized countries experience high lifetime asthma prevalence that has increased over recent decades. Asthma has a complex interplay of genetic and environmental triggers. Studies have revealed complex interactions of lung structure and function genes with environmental exposures such as environmental tobacco smoke and vitamin D. Home environmental strategies can reduce asthma morbidity in children but should be tailored to specific allergens. Coupled with education and severity-specific asthma therapy, tailored interventions may be the most effective strategy to manage childhood asthma.

Risk factors associated with hospital readmission in pediatric asthma

Asthma is a leading cause of hospitalization among children, and about 15-50% of pediatric patients are readmitted after an index admission. The purpose of this integrative review is to explore contemporary scientific findings on the association between pediatric asthma readmission and various demographic, environmental, psychosocial and clinical risk factors. An electronic database search resulted in a sample of 29 studies. African American, public or no insurers, previous admission and complex chronic comorbidity were identified as risk factors associated with pediatric asthma readmission. However, more interdisciplinary and well-designed investigations are warranted to further explicate the spectrum of environmental and psychosocial correlates.