Physical activity levels, pulmonary function, and MRI in children born extremely preterm: A comparison between children with and without bronchopulmonary dysplasia.

INTRODUCTION: Children with a history of bronchopulmonary dysplasia (BPD) may have lower physical activity levels, but evidence to date is mixed. This study compared physical activity levels between children born extremely preterm with and without history of BPD, and examined their associations with pulmonary magnetic resonance imaging (MRI) and pulmonary function test (PFT) indices. METHODS: This multicentre cross-sectional study included children aged 7-9 years born extremely preterm, with and without BPD. Children wore a pedometer for 1 week, then completed the Physical Activity Questionnaire (PAQ), pulmonary MRI, and PFT. Spearman correlations and multivariable linear regression modeling were performed. RESULTS: Of 45 children, 28 had a history of moderate-severe BPD. There were no differences in any physical activity outcomes by BPD status. Higher average daily step count and higher average daily moderate-to-vigorous physical activity (MVPA) were each correlated with greater forced vital capacity (r = 0.41 and 0.58), greater MRI lung proton density at full expiration (r = 0.42 and 0.49), and lower lung clearance index (r = -0.50 and -0.41). After adjusting for MRI total proton density and BPD status, a 5% increase in forced expiratory volume at 1 s was associated with 738 (95% CI: 208, 1268) more steps per day and 0.1 (0.0, 0.2) more hours of MVPA, respectively. CONCLUSION: School-aged children born extremely preterm have similar physical activity levels to their peers, regardless of history of BPD. MRI and PFT measures suggestive of gas trapping and/or airflow obstruction are associated with lower physical activity levels.

Behavioral and emotional characteristics of Canadian children with obesity and moderate-severe sleep-disordered breathing treated with positive airway pressure: longitudinal changes and associations with adherence.

STUDY OBJECTIVES: Behavioral characteristics and outcomes of positive airway pressure (PAP) therapy in children with obesity and moderate-severe sleep-disordered breathing (SDB) have not been reported. Our aims were to 1) determine baseline behavioral/emotional symptoms of this population and characterize changes over time with PAP, and 2) examine associations between baseline behavioral/emotional symptoms and PAP adherence. METHODS: This multicenter prospective cohort study of children with obesity prescribed PAP for moderate-severe SDB assessed PAP adherence (≥ 4 h/night, >50% of nights, usage diaries, downloads) and compared behavioral/emotional characteristics with parent- and child-reported Conners Rating Scale (Conners) and the Child Behavior Checklist (CBCL) at baseline and 1 year after PAP prescription between adherent and nonadherent participants; scores at baseline were compared retrospectively between adherence groups. RESULTS: Twenty-four children were included (median 14.1 years [IQR:12.4,16.0]; 87.5% males). Baseline Conners and CBCL scores were elevated (parent- and child-reported Conners inattention and hyperactivity subscales and CBCL subscales [total, internalizing, externalizing]). Baseline parent-reported Conners scores were significantly more elevated in the nonadherent than adherent group (inattention: 73.3 ± 8.5 vs 60.5 ± 14.6, P = .01; hyperactivity: 70.9 ± 11.1 vs 59.1 ± 16.0, P = .05). This difference was present 1 year later for inattention (P = .01) but not for hyperactivity (P = .09). Parent-reported CBCL scores improved over 1 year in adherent but not nonadherent participants. CONCLUSIONS: We found that children with obesity and moderate-severe SDB have elevated symptoms of behavioral/emotional concerns on standardized testing. Parent-reported emotional characteristics improved in the adherent but not in the nonadherent group. Children with greater inattention/hyperactivity at baseline were less adherent to PAP, suggesting this may contribute to PAP nonadherence. CITATION: Constantin E, MacLean JE, Barrowman N, et al. Behavioral and emotional characteristics of Canadian children with obesity and moderate-severe sleep-disordered breathing treated with positive airway pressure: longitudinal changes and associations with adherence. J Clin Sleep Med. 2023;19(3):555-562.

Understanding the experiences of lung volume recruitment among boys with Duchenne muscular dystrophy: A multicenter qualitative study.

BACKGROUND: Despite recommendations for regular lung volume recruitment (LVR) use in clinical practice guidelines for children with neuromuscular disease, adherence to LVR is poor. We aimed to describe the experience of LVR by boys with Duchenne muscular dystrophy (DMD), their families, and healthcare providers (HCPs), as well as to identify the barriers and facilitators to LVR use. METHODS: This multicenter, qualitative study evaluated boys with DMD (n = 11) who used twice-daily LVR as part of a randomized controlled trial, as well as their parents (n = 11), and HCPs involved in the clinical use of LVR (n = 9). Semistructured interviews were conducted to identify participants' understanding of LVR therapy and their beliefs, barriers and facilitators to its use. Thematic analysis was conducted using an inductive approach. A subanalysis compared adherent and nonadherent children. RESULTS: Seven themes were identified related to participants' beliefs and experiences with LVR: emotional impact, adaptation to LVR, perceived benefits of LVR, routine, family engagement, clinical resources, and equipment-related factors. Strategies to improve adherence were also identified, including education, reinforcement and demonstration of LVR benefit, as well as clinician support. There were no thematic differences between adherent and nonadherent children. DISCUSSION: Despite the benefits of LVR and positive experiences with it by many families, there remain barriers to adherence to treatment. HCPs need to balance the need for early introduction to give families time to adapt to LVR while ensuring that the benefit of LVR outweighs the burden. Clinician support is important for family engagement.

Sleep-disordered breathing symptoms and their association with structural and functional pulmonary changes in children born extremely preterm.

This study aimed to evaluate symptoms of sleep-disordered breathing (SDB) among children born extremely preterm, with and without a history of bronchopulmonary dysplasia (BPD), including associations between sleep and respiratory symptoms, physical activity, pulmonary function, and pulmonary magnetic resonance imaging (MRI). This multi-center cross-sectional study enrolled children aged 7-9 years born extremely preterm with and without BPD. Participants completed the Pediatric Sleep Questionnaire (PSQ), the modified Epworth sleepiness scale, a respiratory symptom questionnaire, pedometer measurements, pulmonary function testing, and pulmonary MRI. Spearman's correlations and univariate and multivariable linear regression modelling were performed. Twenty-eight of 45 children included had a history of moderate-to-severe BPD. The prevalence of sleep-related symptoms was low, with the exception of hyperactivity and inattention. There were no differences in mean (SD) scores on sleep questionnaires in children with and without BPD (PSQ: 0.21 (0.13) vs 0.16 (0.14), p = 0.3; modified Epworth: 2.4 (2.4) vs 1.8 (2.8), p = 0.4). Multiple regression analyses examining difference in sleep scores between groups, adjusting for gestational age and intraventricular hemorrhage, found no statistical difference (p > 0.05). Greater daytime sleepiness was moderately correlated with FEV1%-predicted (r = - 0.52); no other moderate-strong associations were identified.  Conclusions: There was no evidence of clinically important differences in sleep symptoms between children with and without BPD, suggesting that sleep symptoms may be related to prematurity-related factors other than a BPD diagnosis, including airflow limitation. Further research is necessary to explore the relationship between sleep symptoms, airway obstruction, and neurobehavioral symptoms among premature-born children.  Trial registration: NCT02921308. Date of registration: October 3, 2016. What is Known: • Presence of bronchopulmonary dysplasia (BPD) may further contribute to the development of SDB, though its impact is not well-studied. • Premature-born children have a greater risk of lung structural and functional differences, including sleep-disordered breathing (SDB). What is New: • There was no difference in sleep symptoms between children with and without BPD, suggesting that sleep symptoms are related to other prematurity-related factors, such as airflow limitation. • Greater daytime sleepiness was correlated with lower FEV1 in our population, which reflects greater airflow limitation.

Chronic tracheostomy care of ventilator-dependent and -independent children: Clinical practice patterns of pediatric respirologists in a publicly funded (Canadian) healthcare system.

OBJECTIVES: To describe the current clinical practice patterns of Canadian pediatric respirologists at pediatric tertiary care institutions regarding chronic tracheostomy tube care and management of home invasive ventilation. METHODS: A pediatric respirologist/pediatrician with expertise in tracheostomy tube care and home ventilation was identified at each Canadian pediatric tertiary care center to complete a 59-item survey of multiple choice and short answer questions. Domains assessed included tracheostomy tube care, caregiver competency and home monitoring, speaking valves, medical management of tracheostomy complications, decannulation, and long-term follow-up. RESULTS: The response rate was 100% (17/17) with all Canadian tertiary care pediatric centers represented and heterogeneity of practice was observed in all domains assessed. For example, though most centers employ Bivona™ (17/17) and Shiley™ (15/17) tracheostomy tubes, variability was observed around tube change, re-use, and cleaning practices. Most centers require two trained caregivers (14/17) and recommend 24/7 eyes on care and oxygen saturation monitoring. Discharge with an emergency tracheostomy kit was universal (17/17). Considerable heterogeneity was observed in the timing and use of speaking valves and speech-language assessment. Inhaled anti-pseudomonal antibiotics are employed by most centers (16/17) though the indication, agent, and protocol varied by center. Though decannulation practices varied considerably, the requirement of upper airway patency was universally required to proceed with decannulation (17/17) independent of ongoing ventilatory support requirements. CONCLUSION: Considerable variability in pediatric tracheostomy tube care practice exists across Canada. These results will serve as a starting point to standardize and evaluate tracheostomy tube care nationally.

Opioid dose and postoperative respiratory adverse events after adenotonsillectomy in medically complex children.

STUDY OBJECTIVES: Obstructive sleep-disordered breathing is commonly treated with adenotonsillectomy. Our study objective was to describe perioperative opioid dosing in children with a range of medical complexity evaluated for obstructive sleep-disordered breathing undergoing adenotonsillectomy and to investigate its association with postoperative respiratory adverse events (PRAEs). METHODS: A retrospective chart review of children who underwent adenotonsillectomy and had preoperative polysomnography performed was conducted. PRAEs included requiring oxygen, jaw thrust, positive airway pressure, or mechanical ventilation. Multivariable logistic regression was performed to examine for associations between covariates and PRAEs. RESULTS: The cohort included 374 children with obstructive sleep-disordered breathing, median (interquartile range) age 6.1 (3.9, 9.3) years; 344 (92%) had obstructive sleep apnea (apnea-hypopnea index > 1 events/h) while 30 (8%) had a normal polysomnogram (apnea-hypopnea index < 1 events/h). The median (interquartile range) postoperative morphine-equivalent dose administered was 0.17 (0.09, 0.25) mg/kg. Sixty-six (17.6%) experienced at least 1 PRAE. Multivariable modeling identified the following predictors of PRAE: younger age at surgery (odds ratio 0.90, 95% confidence interval 0.83, 0.98), presence of cardiac comorbidity (odds ratio 2.07, 95% confidence interval 1.09, 3.89), and presence of airway anomaly (odds ratio 3.48, 95% confidence interval 1.30, 8.94). Higher total apnea-hypopnea index and morphine-equivalent dose were associated with PRAE risk, and an interaction between these variables was detected (P = .01). CONCLUSIONS: This study identified opioid dose in morphine equivalents to be a strong predictor of PRAE. Additionally, severity of obstructive sleep apnea and postoperative morphine-equivalent dose contributed together and independently to the occurrence of PRAEs. Attention to opioid dosing, particularly among medically complex children with obstructive sleep-disordered breathing, is required to mitigate risk of PRAEs. CITATION: Tsampalieros A, Murto K, Barrowman N, et al. Opioid dose and postoperative respiratory adverse events after adenotonsillectomy in medically complex children. J Clin Sleep Med. 2022;18(10):2405-2413.

Predictors of sleep disordered breathing in children with Down syndrome: a systematic review and meta-analysis.

Children with Down syndrome are at increased risk of sleep disordered breathing (SDB). SDB is associated with significant morbidity including neurocognitive impairment, cardiometabolic disease and systemic inflammation. The identification of clinical markers that may predict SDB is critical in facilitating early diagnosis and treatment, and ultimately, preventing morbidity. The objective of this systematic review was to identify predictors of SDB in patients with Down syndrome. A search was conducted using MEDLINE, Embase, the Cochrane Central Register of Controlled Trials and the Cumulative Index to Nursing and Allied Health Literature. A meta-analysis was performed according to the Meta-analyses of Observational Studies in Epidemiology checklist. Our review of the literature identified inconsistent associations between a variety of variables and SDB in children with Down syndrome, although the quality of evidence was poor. Meta-analysis of age and sex identified that children with OSA were older than those without OSA, and there was a similar risk of OSA in males and females, although risk favoured males. Currently, the American Academy of Pediatrics guidelines recommend that children with Down syndrome undergo polysomnography by the age of 4 years. Our review supports the recommendation for routine screening of children with Down syndrome. However, results from our meta-analysis suggest a need for longitudinal screening to diagnose children who may develop SDB as they get older.

Routine lung volume recruitment in boys with Duchenne muscular dystrophy: a randomised clinical trial.

BACKGROUND: Impaired cough results in airway secretion retention, atelectasis and pneumonia in individuals with Duchenne muscular dystrophy (DMD). Lung volume recruitment (LVR) stacks breaths to inflate the lungs to greater volumes than spontaneous effort. LVR is recommended in DMD clinical care guidelines but is not well studied. We aimed to determine whether twice-daily LVR, compared with standard of care alone, attenuates the decline in FVC at 2 years in boys with DMD. METHODS: In this multicentre, assessor-blinded, randomised controlled trial, boys with DMD, aged 6-16 years with FVC >30% predicted, were randomised to receive conventional treatment or conventional treatment plus manual LVR twice daily for 2 years. The primary outcome was FVC % predicted at 2 years, adjusted for baseline FVC % predicted, age and ambulatory status. Secondary outcomes included change in chest wall distensibility (maximal insufflation capacity minus FVC) and peak cough flow. RESULTS: Sixty-six boys (36 in LVR group, 30 in control) were evaluated (median age (IQR): 11.5 years (9.5-13.5), median baseline FVC (IQR): 85% predicted (73-96)). Adjusted mean difference in FVC between groups at 2 years was 1.9% predicted (95% CI -6.9% to 10.7%; p=0.68) in the direction of treatment benefit. We found no differences in secondary outcomes. CONCLUSION: There was no difference in decline in FVC % predicted with use of twice-daily LVR for boys with DMD and relatively normal lung function. The burden associated with routine LVR may outweigh the benefit. Benefits of LVR to maintain lung health in boys with worse baseline lung function still need to be clarified. TRIAL REGISTRATION NUMBER: NCT01999075.

Risk factors for respiratory adverse events after adenoidectomy and tonsillectomy in children with down syndrome: a retrospective cohort study.

Obstructive sleep apnea syndrome is a major cause of morbidity in the Down syndrome population and is commonly treated with adenoidectomy and/or tonsillectomy (AT). However, these children are at increased risk for perioperative respiratory adverse events (PRAEs). The objective of this study was to examine risk factors for major PRAEs requiring intervention in children with Down syndrome undergoing AT and to describe their postoperative monitoring environment. This retrospective study included all children with Down syndrome aged 0-18 years who underwent a preoperative polysomnogram followed by AT at a tertiary pediatric institution. Descriptive statistics were used to summarize baseline demographic and clinical characteristics. A multivariable model for prediction of PRAEs was constructed. A priori, it was decided that minimum oxygen saturation, apnea-hypopnea index, and average oxygen saturation asleep would be included, along with medical comorbidities associated with PRAEs at p < 0.2 in univariable analyses. Fifty-eight children were included in this study; twelve had a PRAE. Cardiac disease was associated with PRAEs on univariable analysis (p = 0.03). In multivariable analysis, average oxygen saturation asleep was associated with PRAEs (OR 1.50; 95% confidence interval 1.00, 2.41; p = 0.05). For all of the remaining variables, p > 0.15. Fifty-six children were admitted for monitoring overnight; four were admitted to the intensive care unit and fifty-two were admitted to the ward. CONCLUSIONS: A multivariable model found evidence that lower average oxygen saturation while asleep was associated with PRAEs requiring intervention in children with Down syndrome. This study highlights the difficulty in predicting complications in this population. WHAT IS KNOWN: • Obstructive sleep apnea syndrome is a major cause of morbidity in the Down syndrome population and is commonly treated with adenoidectomy and/or tonsillectomy. • However, children with Down syndrome are at increased risk for perioperative respiratory adverse events (PRAEs) following adenoidectomy and/or tonsillectomy. WHAT IS NEW: • We found that a lower average oxygen saturation asleep is associated with increased odds of PRAEs, adjusting for age, total apnea-hypopnea index, cardiac comorbidity, and minimum oxygen saturation. • This study highlights the difficulty in predicting complications in this population.

Pulmonary Magnetic Resonance Imaging of Ex-Preterm Children with and without Bronchopulmonary Dysplasia.

Rationale: Children born prematurely, particularly those with bronchopulmonary dysplasia, have persisting lung abnormalities requiring longitudinal monitoring. Pulmonary ultrashort echo time magnetic resonance imaging (MRI) measurements may provide sensitive markers of persisting lung abnormalities and have not been evaluated in school-aged children born prematurely. Objectives: To compare pulmonary MRI and pulmonary function test measurements in preterm-born school-aged children with and without bronchopulmonary dysplasia. Methods: Children aged 7-9 years, born extremely preterm, with and without bronchopulmonary dysplasia, were recruited from three centers. Participants underwent pulmonary ultrashort echo time MRI and pulmonary function tests. Primary outcomes included total proton density and proton density at full expiration, measured using MRI. Multiple linear regression analysis was performed, adjusting for gestational age and bronchopulmonary dysplasia. Associations between MRI and pulmonary function were tested. Results: Thirty-five children were included in the primary analysis (24 with bronchopulmonary dysplasia, 11 without); 29 completed pulmonary function tests, of whom 11 (38%) had airflow limitation. Children with bronchopulmonary dysplasia had 44% (95% confidence interval [CI], 10-66%) lower mean total proton density (mean ± standard deviation, 3.6 ± 2.6) than those without (6.1 ± 4.0). Those with bronchopulmonary dysplasia had 25% (95% CI, 3-42%) lower proton density at full expiration than those without. Lower total proton density and proton density at full expiration were moderately correlated with greater residual volume, residual volume/total lung capacity, and lung clearance index (Spearman correlations for total proton density: -0.42, -0.57, and -0.53, respectively. Spearman correlations for proton density at full expiration: -0.28, -0.57, and -0.45, respectively). Conclusions: School-aged preterm-born children with bronchopulmonary dysplasia have parenchymal tissue abnormalities measured using ultrashort MRI proton density, compared with those without. MRI proton density correlated with pulmonary function measures indicative of gas trapping. Clinical trial registered with www.clinicaltrials.gov (NCT02921308).

Blood pressure variability in children with obesity and sleep-disordered breathing following positive airway pressure treatment.

Obese youth with sleep-disordered breathing are treated with positive airway pressure to improve sleep and cardiovascular status. While improvements in sleep parameters have been confirmed, a study by Katz et al. showed no major improvement in ambulatory blood pressure. The aim of this ancillary study was to analyze short-term blood pressure variability, following positive airway pressure treatment, as a more sensitive marker of cardiovascular health. We analyzed 24-h blood pressure variability data in 17 children, taken at baseline and after 12 months of treatment. These data were derived from an already published prospective, multicenter cohort study conducted in 27 youth (8-16 years) with obesity who were prescribed 1-year of positive airway pressure for moderate-severe sleep-disordered breathing. Significant decreases were found in 24 h systolic blood pressure (p = 0.040) and nighttime diastolic blood pressure (p = 0.041) average real variability, and diastolic blood pressure (p = 0.035) weighted standard deviation. Significant decreases were noted in nighttime diastolic blood pressure time rate variability (p = 0.007). Positive airway pressure treatment resulted in a significant decrease in blood pressure variability, suggesting a clinically significant improvement of sympathetic nerve activity in youth with obesity and sleep-disordered breathing. IMPACT: Cardiovascular variability, as measured by blood pressure variability, is improved in children following positive airway pressure treatment. Our novel findings of improved blood pressure time rate variability are the first described in the pediatric literature. Future studies aimed at analyzing target organ damage in this patient population will allow for a better understanding as to whether alterations in blood pressure variability translate to decreasing target organ damage in children, as seen in adults.

Objective measurement of lung volume recruitment therapy: laboratory and clinical validation.

Lung volume recruitment manoeuvres are often prescribed to maintain respiratory health in neuromuscular disease. Unfortunately, no current system accurately records delivered dose. This study determined the performance characteristics of a novel, objective, manual lung volume recruitment bag counter ('the counter') with bench and healthy volunteer testing, as well as in individuals with neuromuscular disease. We undertook (1) bench test determination of activation threshold, (2) bench and healthy volunteer fidelity testing during simulated patient interface leak and different pressure compressions and (3) comparisons with self-report in individuals with neuromuscular disease. The data are reported as summary statistics, compression counts, percentage of recorded versus delivered compressions and concordance (Cohen's kappa (K) and absolute agreement). RESULTS: Minimum counter activation pressure under conditions of zero leak was 1.9±0.4 cm H2O. No difference was observed between the number of repetitions delivered and recorded during high airway pressure condition. Interface leak approximating 25% resulted in underestimation of repetition counts, and once the leak was at 50% or beyond, the counter recorded no activity. Faster sampling frequency collected data with more fidelity. Counter data agreed with diary self-report during community trials (16 participants, 960 participant days, 77% agreement, Cohen's Κ=0.66 and p<0.001). Disagreement typically favoured more diary reported (18%) than counter (5%) sessions. CONCLUSIONS: The performance characteristics of a new lung volume recruitment counter have been established in both laboratory and community settings. Objective usage and dosage data should accelerate new knowledge development and better translation of lung volume recruitment therapy into policy and practice.

Polysomnography parameters as predictors of respiratory adverse events following adenotonsillectomy in children.

STUDY OBJECTIVES: The first-line treatment of obstructive sleep apnea syndrome in children is adenotonsillectomy, but this may result in perioperative respiratory adverse events (PRAEs). The primary aim of this study is to examine whether the McGill oximetry score (MOS) and other polysomnography parameters can predict major PRAEs following adenotonsillectomy. We secondarily evaluated the MOS interrater reliability and correlation with other polysomnography parameters. METHODS: This retrospective study included all children aged 0-18 years who underwent preoperative polysomnography between June 2010 and January 2016 prior to adenotonsillectomy at a tertiary pediatric institution. Oximetries from polysomnograms were assigned an MOS. Univariable and multivariable models for prediction of major PRAEs were constructed. MOS was correlated with polysomnography parameters and interrater reliability was evaluated. RESULTS: This study included 106 children; 15 had a major PRAE. A multivariable prediction model that combined MOS and age showed evidence for the ability to predict major PRAEs with an area under the receiver operating characteristic curve of 0.68 (95% confidence interval: 0.52, 0.84), whereby increased MOS and younger age were associated with PRAEs, but apnea-hypopnea index was not. MOS had excellent interrater reliability (κ = 0.95) and was highly correlated with oxygen saturation nadir and cumulative time percentage with oxygen saturation less than 90%. CONCLUSIONS: A prediction model including MOS and age may predict PRAEs following adenotonsillectomy. This suggests that nocturnal oximetry provides the most essential information of polysomnography measures to direct postoperative monitoring following adenotonsillectomy. CITATION: Xiao L, Barrowman N, Momoli F, et al. Polysomnography parameters as predictors of respiratory adverse events following adenotonsillectomy in children. J Clin Sleep Med. 2021;17(11):2215-2223.

Clinical predictors of nonadherence to positive airway pressure therapy in children: a retrospective cohort study.

STUDY OBJECTIVES: Despite the importance of treating sleep-disordered breathing, positive airway pressure adherence rates in children are low. Identifying readily available predictors of nonadherence would enable the development of targeted interventions and supports, but literature is limited. Our objective was to identify baseline clinical predictors of 6-month positive airway pressure therapy nonadherence in children with SDB through a retrospective cohort study. METHODS: This study evaluated children (ages 8-17 years) prescribed positive airway pressure therapy for sleep-disordered breathing between 2011 and 2017 at a single pediatric tertiary hospital. The primary outcome was nonadherence at 6 months, measured using both machine downloads and self-report. Candidate baseline predictors included demographics, comorbidities, and sleep-disordered breathing characteristics. Relative risks (RR) and 95% confidence intervals (CI) were estimated using a modified Poisson regression. Missing data were imputed prior to analysis. RESULTS: The study included 104 children. The independent predictors most strongly associated with greater nonadherence were older age (RR = 1.08 for a 1-year increase; 95% CI, 1.00-1.16) and higher oxygen saturation nadir (RR = 1.03 for a 1% increase; 95% CI, 1.00-1.05), whereas those most strongly associated with lower nonadherence were higher arousal index (RR = 0.97 for a 1 event/h increase; 95% CI, 0.95-1.00), developmental delay (RR = 0.58; 95% CI, 0.30-1.13), and asthma (RR = 0.72; 95% CI, 0.44-1.17). CONCLUSIONS: Overall, children who are older, have less-severe sleep-disordered breathing, or less-disrupted sleep at baseline are more likely to be nonadherent to positive airway pressure therapy and may benefit from additional supports to acclimatize to therapy. As clinical predictors were only weakly associated with nonadherence, nonclinical characteristics may play a larger role in predicting adherence.

Does neck circumference predict obstructive sleep apnea in children with obesity?

OBJECTIVES: Obstructive sleep apnea (OSA) affects 10-50% of children with obesity, but its identification is challenging and wait times for testing are long. Previous studies suggest that neck circumference (NC) and neck-to-height ratio (NHR) may predict OSA. Our objectives were to 1) evaluate associations of NC and NHR with OSA; 2) model NHR as a predictor of OSA, adjusting for age, sex, and Tanner stage; and 3) identify thresholds of NHR associated with OSA, in children with obesity. METHODS: Participants were aged 8-17 years, with obesity (BMI >95%ile), undergoing polysomnography. Associations between NC and NHR with OSA were evaluated. NHR, age, sex and self-reported Tanner stage (early/late) were included in a negative binomial multiple regression model to predict obstructive apnea hypopnea index (OAHI). RESULTS: 71 children participated, with median age 14.8 years (IQR 12.6, 16.0), 54% male, median BMI z-score 2.5 (IQR 2.3, 2.7), and 77% late Tanner stage. OSA was severe in 18 children (25.4%), moderate in 12 (16.9%), and mild in 18 (25.4%). In the model, each 0.01 increase in NHR was associated with a 55% increase in OAHI (95% CI: 36%, 80%); boys had a 119% higher OAHI than girls (95% CI: 10%, 337%). Threshold NHR associated with moderate-severe OSA was 0.25 in females and 0.23 in males. CONCLUSIONS: NHR and male sex independently predict OSA severity in children with obesity, adjusting for age and Tanner stage. Children with obesity and NHR above identified thresholds are more likely to have moderate-severe OSA, and may benefit from earlier polysomnography.

Creating enriched training sets of eligible studies for large systematic reviews: the utility of PubMed's Best Match algorithm.

INTRODUCTION: Solutions like crowd screening and machine learning can assist systematic reviewers with heavy screening burdens but require training sets containing a mix of eligible and ineligible studies. This study explores using PubMed's Best Match algorithm to create small training sets containing at least five relevant studies. METHODS: Six systematic reviews were examined retrospectively. MEDLINE searches were converted and run in PubMed. The ranking of included studies was studied under both Best Match and Most Recent sort conditions. RESULTS: Retrieval sizes for the systematic reviews ranged from 151 to 5,406 records and the numbers of relevant records ranged from 8 to 763. The median ranking of relevant records was higher in Best Match for all six reviews, when compared with Most Recent sort. Best Match placed a total of thirty relevant records in the first fifty, at least one for each systematic review. Most Recent sorting placed only ten relevant records in the first fifty. Best Match sorting outperformed Most Recent in all cases and placed five or more relevant records in the first fifty in three of six cases. DISCUSSION: Using a predetermined set size such as fifty may not provide enough true positives for an effective systematic review training set. However, screening PubMed records ranked by Best Match and continuing until the desired number of true positives are identified is efficient and effective. CONCLUSIONS: The Best Match sort in PubMed improves the ranking and increases the proportion of relevant records in the first fifty records relative to sorting by recency.

Cardiovascular changes in children with obstructive sleep apnea and obesity after treatment with noninvasive ventilation.

STUDY OBJECTIVES: Adults with obesity and obstructive sleep apnea (OSA) are at risk for cardiometabolic disease, and this risk likely extends to children with both conditions. Noninvasive ventilation (NIV; including continuous and bilevel positive airway pressure) is often used to treat OSA in children with obesity. The aim of this study was to examine the impact of NIV treatment on heart rate variability (HRV), as a marker of cardiovascular risk, in children with obesity and newly diagnosed OSA. METHODS: A prospective multicenter cohort study was conducted in children with obesity prescribed NIV therapy for newly diagnosed moderate-severe OSA. Measurements of HRV were derived from polysomnography recordings at baseline and after 12 months of treatment. HRV parameters were examined by sleep stage, before and after arousal and oxygen desaturation events. HRV parameters were compared between time points using pair t tests as well as mixed model analysis. RESULTS: Twelve children had appropriate data for analysis at baseline and 12 months. Heart rate decreased by 4.5 beats/min after NIV treatment, with no change in HRV parameters. HRV parameters differed by sleep stage and showed an increase in arousal-related sympathetic-parasympathetic balance after 12 months of NIV treatment. HRV parameters did not differ before and after oxygen desaturation events. CONCLUSIONS: NIV for the treatment in children with obesity and OSA resulted in a small decrease in heart rate and an increase in arousal-related sympathetic-parasympathetic balance. These findings suggest small, potentially positive impacts of NIV on cardiovascular risk in children with concurrent obesity and OSA.

Healthcare utilization and costs of pediatric home mechanical ventilation in Canada.

BACKGROUND: Children using home mechanical ventilation (HMV) live at home with better quality of life, despite financial burden for their family. Previous studies of healthcare utilization and costs have not considered public and private expenditures, including family caregiver time. Our objective was to examine public and private healthcare utilization and costs for children using HMV, and variables associated with highest costs. METHODS: Longitudinal, prospective, observational cost analysis study (2012-2014) collecting data on public and private (out-of-pocket, third-party insurance, and caregiving) costs every 2 weeks for 6 months using the Ambulatory Home Care Record. Functional Independence Measure (FIM), WeeFIM, and Caregiving Impact Scale (CIS) were measured at baseline and study completion. Regression modeling examined a priori selected variables associated with monthly costs using Andersen and Newman's framework for healthcare utilization, relevant literature, and clinical expertise. Data are reported in 2015 Canadian dollars ($1CAD = $0.78USD). RESULTS: Forty two children and their caregivers were enrolled. Overall median (interquartile range) monthly healthcare cost was $12 131 ($8159-$15 958) comprising $9929 (89%) family caregiving hours, $996 (9%) publicly funded, and $252 (2%) out-of-pocket (<1% third-party insurance) costs. With higher FIM score (lower dependency), median costs were reduced by 4.5% (95% confidence interval: 8.3%-0.5%), adjusted for age, sex, tracheostomy, and daily ventilation duration. Note: since the three cost categories did not sum to the total statistically derived median cost, the percentage of each category used the sum of median public + caregiver lost time + private out-of-pocket + third-party insurance as the denominator. CONCLUSIONS: For HMV children, most healthcare costs were due to family caregiving costs. More dependent children incur highest costs. The financial burden to family caregivers is substantial and needs to considered in future policy decisions related to pediatric HMV.