Clinical validation of digital biomarkers for paediatric patients with asthma and cystic fibrosis: potential for clinical trials and clinical care.

BACKGROUND: Digital biomarkers are a promising novel method to capture clinical data in a home setting. However, clinical validation prior to implementation is of vital importance. The aim of this study was to clinically validate physical activity, heart rate, sleep and forced expiratory volume in 1 s (FEV1) as digital biomarkers measured by a smartwatch and portable spirometer in children with asthma and cystic fibrosis (CF). METHODS: This was a prospective cohort study including 60 children with asthma and 30 children with CF (aged 6-16 years). Participants wore a smartwatch, performed daily spirometry at home and completed a daily symptom questionnaire for 28 days. Physical activity, heart rate, sleep and FEV1 were considered candidate digital end-points. Data from 128 healthy children were used for comparison. Reported outcomes were compliance, difference between patients and controls, correlation with disease activity, and potential to detect clinical events. Analysis was performed with linear mixed effects models. RESULTS: Median compliance was 88%. On average, patients exhibited lower physical activity and FEV1 compared with healthy children, whereas the heart rate of children with asthma was higher compared with healthy children. Days with a higher symptom score were associated with lower physical activity for children with uncontrolled asthma and CF. Furthermore, FEV1 was lower and (nocturnal) heart rate was higher for both patient groups on days with more symptoms. Candidate biomarkers appeared able to describe a pulmonary exacerbation. CONCLUSIONS: Portable spirometer- and smartwatch-derived digital biomarkers show promise as candidate end-points for use in clinical trials or clinical care in paediatric lung disease.

A virtual asthma clinic for children: fewer routine outpatient visits, same asthma control.

eHealth is an appealing medium to improve healthcare and its value (in addition to standard care) has been assessed in previous studies. We aimed to assess whether an eHealth intervention could improve asthma control while reducing 50% of routine outpatient visits.In a multicentre, randomised controlled trial with a 16-month follow-up, asthmatic children (6-16 years) treated in eight Dutch hospitals were randomised to usual care (4-monthly outpatient visits) and online care using a virtual asthma clinic (VAC) (8-monthly outpatient visits with monthly web-based monitoring). Outcome measures were the number of symptom-free days in the last 4 weeks of the study, asthma control, forced expiratory volume in 1 s, exhaled nitric oxide fraction, asthma exacerbations, unscheduled outpatient visits, hospital admissions, daily dose of inhaled corticosteroids and courses of systemic corticosteroids.We included 210 children. After follow-up, symptom-free days differed statistically between the usual care and VAC groups (difference of 1.23 days, 95% CI 0.42-2.04; p=0.003) in favour of the VAC. In terms of asthma control, the Childhood Asthma Control Test improved more in the VAC group (difference of 1.17 points, 95% CI 0.09-2.25; p=0.03). No differences were found for other outcome measures.Routine outpatient visits can partly be replaced by monitoring asthmatic children via eHealth.

The validity of biochemical markers in metabolic bone disease in preterm infants: a systematic review.

UNLABELLED: To establish the validity of biochemical markers of metabolic bone disease (MBD) in preterm infants. CONCLUSION: There is insufficient evidence that any of the frequently used serum measurements are valid biochemical markers of MBD in preterm infants. Increased urinary calcium concentration may be a valid biochemical marker, but more research is necessary to confirm this.

Development and technical validation of a smartphone-based pediatric cough detection algorithm.

INTRODUCTION: Coughing is a common symptom in pediatric lung disease and cough frequency has been shown to be correlated to disease activity in several conditions. Automated cough detection could provide a noninvasive digital biomarker for pediatric clinical trials or care. The aim of this study was to develop a smartphone-based algorithm that objectively and automatically counts cough sounds of children. METHODS: The training set was composed of 3228 pediatric cough sounds and 480,780 noncough sounds from various publicly available sources and continuous sound recordings of 7 patients admitted due to respiratory disease. A Gradient Boost Classifier was fitted on the training data, which was subsequently validated on recordings from 14 additional patients aged 0-14 admitted to the pediatric ward due to respiratory disease. The robustness of the algorithm was investigated by repeatedly classifying a recording with the smartphone-based algorithm during various conditions. RESULTS: The final algorithm obtained an accuracy of 99.7%, sensitivity of 47.6%, specificity of 99.96%, positive predictive value of 82.2% and negative predictive value 99.8% in the validation dataset. The correlation coefficient between manual- and automated cough counts in the validation dataset was 0.97 (p < .001). The intra- and interdevice reliability of the algorithm was adequate, and the algorithm performed best at an unobstructed distance of 0.5-1 m from the audio source. CONCLUSION: This novel smartphone-based pediatric cough detection application can be used for longitudinal follow-up in clinical care or as digital endpoint in clinical trials.

Supplemental oxygen strategies in infants with bronchopulmonary dysplasia after the neonatal intensive care unit period: study protocol for a randomised controlled trial (SOS BPD study).

INTRODUCTION: Supplemental oxygen is the most important treatment for preterm born infants with established bronchopulmonary dysplasia (BPD). However, it is unknown what oxygen saturation levels are optimal to improve outcomes in infants with established BPD from 36 weeks postmenstrual age (PMA) onwards. The aim of this study is to compare the use of a higher oxygen saturation limit (≥95%) to a lower oxygen saturation limit (≥90%) after 36 weeks PMA in infants diagnosed with moderate or severe BPD. METHODS AND ANALYSIS: This non-blinded, multicentre, randomised controlled trial will recruit 198 preterm born infants with moderate or severe BPD between 36 and 38 weeks PMA. Infants will be randomised to either a lower oxygen saturation limit of 95% or to a lower limit of 90%; supplemental oxygen and/or respiratory support will be weaned based on the assigned lower oxygen saturation limit. Adherence to the oxygen saturation limit will be assessed by extracting oxygen saturation profiles from pulse oximeters regularly, until respiratory support is stopped. The primary outcome is the weight SD score at 6 months of corrected age. Secondary outcomes include anthropometrics collected at 6 and 12 months of corrected age, rehospitalisations, respiratory complaints, infant stress, parental quality of life and cost-effectiveness. ETHICS AND DISSEMINATION: Ethical approval for the trial was obtained from the Medical Ethics Review Committee of the Erasmus University Medical Centre, Rotterdam, the Netherlands (MEC-2018-1515). Local approval for conducting the trial in the participating hospitals has been or will be obtained from the local institutional review boards. Informed consent will be obtained from the parents or legal guardians of all study participants. TRIAL REGISTRATION NUMBER: NL7149/NTR7347.

Timing of group B streptococcus screening in pregnancy: a systematic review.

BACKGROUND: Group B streptococcus (GBS) is an important cause of neonatal sepsis. Guidelines advise to collect cultures at 35-37 weeks' gestation and to administer intrapartum antibiotic prophylaxis in case of GBS-positive cultures, as well as in all preterm deliveries. Improved effectiveness of antenatal cultures might help to further decrease GBS early-onset disease. OBJECTIVE: To determine the best timing of antenatal cultures, which may help establish optimal prevention of perinatal GBS infection in both term and preterm neonates. METHODS: PubMed and EMBASE databases were searched for relevant articles published from 1966 to February 2009. Nine articles were included. Information about study features and predictive values of antenatal cultures were abstracted. RESULTS: Positive predictive values for antenatal GBS cultures ranged from 43 to 100% (mean 69%) and negative predictive values from 80 to 100% (mean 94%). GBS cultures collected in late pregnancy had high positive predictive values for colonization during delivery. The negative predictive value was high and relatively constant regardless of GA. CONCLUSIONS: This systematic review confirms recommendations to screen pregnant women for colonization of GBS at 35-37 weeks' gestation, but one should be aware of the limitations of screening, with 6% of GBS carriers remaining undetected in antenatal cultures.

Technical validity and usability of a novel smartphone-connected spirometry device for pediatric patients with asthma and cystic fibrosis.

BACKGROUND: Diagnosis and follow-up of respiratory diseases traditionally rely on pulmonary function tests (PFTs), which are currently performed in hospitals and require trained personnel. Smartphone-connected spirometers, like the Air Next spirometer, have been developed to aid in the home monitoring of patients with pulmonary disease. The aim of this study was to investigate the technical validity and usability of the Air Next spirometer in pediatric patients. METHODS: Device variability was tested with a calibrated syringe. About 90 subjects, aged 6 to 16, were included in a prospective cohort study. Fifty-eight subjects performed conventional spirometry and subsequent Air Next spirometry. The bias and the limits of agreement between the measurements were calculated. Furthermore, subjects used the device for 28 days at home and completed a subject-satisfaction questionnaire at the end of the study period. RESULTS: Interdevice variability was 2.8% and intradevice variability was 0.9%. The average difference between the Air Next and conventional spirometry was 40 mL for forced expiratory volume in 1 second (FEV1) and 3 mL for forced vital capacity (FVC). The limits of agreement were -270 mL and +352 mL for FEV1 and -403 mL and +397 mL for FVC. About 45% of FEV1 measurements and 41% of FVC measurements at home were acceptable and reproducible according to American Thoracic Society/European Respiratory Society criteria. Parents scored difficulty, usefulness, and reliability of the device 1.9, 3.5, and 3.8 out of 5, respectively. CONCLUSION: The Air Next device shows validity for the measurement of FEV1 and FVC in a pediatric patient population.

Therapeutic drug monitoring of aminoglycosides in neonates.

The efficacy and toxicity of aminoglycosides show a strong direct positive relationship with blood drug concentrations, therefore, therapy with aminoglycosides in adults is usually guided by therapeutic drug monitoring. Dosing regimens in adults have evolved from multiple daily dosing to extended-interval dosing. This evolution has also taken place in neonates. Neonates, however, display large interindividual differences in the pharmacokinetics of aminoglycosides due to developmental differences early in life. The volume of distribution of aminoglycosides shows a strong relationship with bodyweight, which tends to be larger (corrected for bodyweight) in more premature infants and those with sepsis. Renal clearance of aminoglycosides increases with gestational age and accelerates immediately after birth. Because of these developmental influences, there is great inter- and intraindividual variability in the volume of distribution and clearance of these drugs, and investigators have established aminoglycoside dosing regimens based on bodyweight and/or gestational age. Widely practised dosing regimens comprise 4-5 mg/kg bodyweight of gentamicin every 24-48 hours as a first dose, followed by dose adjustment based on therapeutic drug monitoring. Although formal toxicity studies are scarce, there is no evidence that aminoglycoside toxicity in neonates differs from that in adults. Monitoring of blood drug concentrations and intelligent reconstruction of individual pharmacokinetic behaviour using a population pharmacokinetic model, optimally chosen blood sampling times and appropriate pharmacokinetic software, help clinicians to quickly optimize aminoglycoside dosing regimens to maximize the clinical effect and minimize the toxicity of these drugs.

Association between colonization with Group B Streptococcus and preterm delivery: a systematic review.

Up to 36% of pregnant women are colonized with Group B Streptococcus (GBS). Preterm delivery in colonized mothers is a risk factor for early onset neonatal GBS disease, but whether maternal GBS genital colonization is related to preterm delivery is unclear. The objective of this review was to determine the relationship between maternal colonization with GBS and preterm delivery. Pubmed searches and reference lists of all selected publications were used to find studies reporting on the relationship between maternal GBS colonization and preterm delivery. Study characteristics were abstracted, and validity scores were performed. To assess the relationship between GBS colonization and pregnancy outcome, four-fold prognostic tables were constructed for each study. Out of more than 60 full-text articles, 16 follow-up studies and four case control studies were included in this review. Follow-up studies were divided into 'cohort studies,' in which cultures were taken early in pregnancy and which reported on pregnancy outcome, and 'cross-sectional studies', in which cultures were collected during delivery. Studies differed widely in methods, validity score, and GBS prevalence. The combined estimate from a random effect meta-analysis of the 11 cohort studies was 1.06 (95% confidence intervals (CI) 0.95-1.19) and for the five cross-sectional studies 1.75 (95% CI 1.43-2.14). For the case control studies, the pooled odds ratio was 1.59 (95% CI 1.03-2.44). This systematic review did not show an association between maternal GBS colonization during pregnancy and preterm delivery. However, in case of preterm delivery, there is an increased risk of subsequent maternal GBS colonization.

Low rate of carriage of macrolide-resistant group B streptococci in pregnant women in The Netherlands.

OBJECTIVES: To describe prevalence of phenotypic and genotypic macrolide-resistance among GBS isolates in pregnant women and explore the possibility of clonal spread of resistant GBS isolates in a multicultural population. STUDY DESIGN: Antimicrobial resistance patterns of 107 GBS isolates obtained from asymptomatic pregnant women were determined using E-tests. Macrolide resistance genes mef(A), erm(TR) and erm(B) were determined with PCR and a subset of 39 isolates, including the 8 isolates harbouring macrolide resistance genes, was subjected to RAPD analysis to detect clonal spreading. RESULTS: Resistance to erythromycin and clindamycin was found in 8% and 7%, respectively. Macrolide resistance genes mef(A), erm(TR) and erm(B) were found in 1, 2 and 5 isolates, respectively; only five of these eight isolates exhibited both genotypic as well as phenotypic resistance. One genotype occured in 36% of the subset. CONCLUSIONS: Earlier reports on prevalence of phenotypic resistance were confirmed. Among the susceptible isolates one clonal type of GBS was clearly predominant; one of the resistant isolates shared its genotype. When such clonal types acquire resistance traits in the future, GBS disease may become harder to control.

Epidemiology of Sepsis-like Illness in Young Infants: Major Role of Enterovirus and Human Parechovirus.

BACKGROUND: Sepsis-like illness is a main cause for hospital admission in young infants. Our aim was to investigate incidence, epidemiology and clinical characteristics of enterovirus (EV) and human parechovirus (HPeV) infections in young infants with sepsis-like illness. METHODS: This is a prospective observational cohort study in which infants younger than 90 days of age, presenting with sepsis-like symptoms in a secondary care children's hospital, underwent a full sepsis work-up. Clinical signs and infectious indices were recorded. EV or HPeV RNA was detected by polymerase chain reaction in plasma and/or cerebrospinal fluid (CSF). RESULTS: Infants were diagnosed with EV, HPeV, fever of unknown origin or severe infection. EV and HPeV were detected in 132 of 353 (37%) and 52 of 353 (15%) of cases, respectively. EV and HPeV have distinct seasonability. Some differences in clinical signs and symptoms occurred between children with EV and HPeV infection but were of limited clinical value. CSF pleocytosis occurred in 44% of EV positive infants, and only in 13% of those with HPeV infection. CONCLUSIONS: EV and HPeV infections are major causes of sepsis-like illness in infants < 90 days of age. Neither clinical characteristics nor laboratory indices were predictive for EV/HPeV infection. CSF pleocytosis occurs, but not in all patients. Testing for EV and HPeV in all young infants with sepsis-like illness is strongly advised.

Recombinant human deoxyribonuclease in infants with respiratory syncytial virus bronchiolitis.

BACKGROUND: Treatment of hospitalized infants with respiratory syncytial virus (RSV) bronchiolitis is mainly supportive. Bronchodilators and systemic steroids are often used but do not reduce the length of hospital stay. Because hypoxia and airways obstruction develop secondary to viscous mucus in infants with RSV bronchiolitis, and because free DNA is present in RSV mucus, we tested the efficacy of the mucolytic drug recombinant human deoxyribonuclease (rhDNase). METHODS: In a multicenter, randomized, double-blind, controlled clinical trial, 225 oxygen-dependent infants admitted to the hospital for RSV bronchiolitis were randomly assigned to receive 2.5 mg bid of nebulized rhDNase or placebo until discharge. The primary end point was length of hospital stay. Secondary end points were duration of supplemental oxygen, improvement in symptom score, and number of intensive care admissions. RESULTS: There were no significant differences between the groups with regard to the length of hospital stay (p = 0.19) or the duration of supplemental oxygen (p = 0.07). The ratio (rhDNase/placebo) of geometric means of length of stay was 1.12 (95% confidence interval, 0.96 to 1.33); for the duration of supplemental oxygen, the ratio was 1.28 (95% confidence interval, 0.97 to 1.68). There were no significant differences in the rate of improvement of the symptom score or in the number of intensive care admissions. CONCLUSIONS: Administration of rhDNase did not reduce the length of hospital stay or the duration of supplemental oxygen in oxygen-dependent infants with RSV bronchiolitis.

Prevalence of colonisation with group B Streptococci in pregnant women of a multi-ethnic population in The Netherlands.

OBJECTIVE: This study was performed to determine the prevalence of GBS and to identify GBS colonisation risk factors in a multicultural population of pregnant women in The Netherlands. We calculated predictive values of cultures in pregnancy for intrapartum GBS carriage. STUDY DESIGN: From a total of 1702 women visiting several antenatal outpatient departments, rectovaginal swabs were collected at 35-37 weeks' gestation. In 761 women swabs were repeated at time of delivery. Carriage of GBS late in third trimester and at time of delivery was analysed in relation to age, parity, ethnicity and socio-economic status. RESULTS: Twenty-one percent was GBS carrier late in pregnancy. Compared to Europeans, African women were at a higher risk (29%, RR 1.4, CI 1.1-1.7) and Asian women were at lower risk (13%, RR 0.6, CI 0.4-0.8) for GBS carriage. No differences in colonisation were found between women with respect to age, parity or socio-economic background. Positive predictive value of GBS carriage at 35-37 weeks' gestation for carriage at time of parturition was 79% and negative predictive value was 93%. CONCLUSIONS: It was not possible to identify a group of pregnant women at high risk for GBS colonisation. Predictive values of antenatal genital group B streptococci cultures at 35-37 weeks' gestation for intrapartum GBS carriage are lower than previously reported.

[Haemoptysis in children: diagnose and act]. / Kinderen die bloed ophoesten: lokaliseren en handelen.

BACKGROUND: Haemoptysis, coughing up blood from the respiratory tract distal to the vocal cords, is a rare symptom in children, and the cause is difficult to determine. The symptom can cause anxiety for the child, parents and treating physician. CASE DESCRIPTION: We describe two cases of adolescents who presented at the Accident and Emergency Unit with acute onset dyspnoea and haemoptysis. In patient A, the haemoptysis was caused by tuberculosis, a known but rare cause of haemoptysis in the Netherlands. Patient B was found to have pseudohaemoptysis, which always has to be differentiated from haemoptysis. CONCLUSION: Although haemoptysis in children is usually mild and self-limiting, knowledge about the possible underlying causes and necessary diagnostic workup is essential in order to reach the right diagnosis promptly and start appropriate treatment in case of life threatening haemoptysis.

Effects of individualized developmental care in a randomized trial of preterm infants <32 weeks.

OBJECTIVE: The goal was to investigate the effects of the Newborn Individualized Developmental Care and Assessment Program (NIDCAP) on days of respiratory support and intensive care, growth, and neuromotor development at term age for infants born at <32 weeks. METHODS: Infants were assigned randomly, within 48 hours after birth, to a NIDCAP group or basic developmental care (control) group. The NIDCAP intervention consisted of weekly formal behavioral observations of the infants and caregiving recommendations and support for staff members and parents, as well as incubator covers and positioning aids. The control group infants were given basic developmental care, which consisted of only incubator covers and positioning aids. Outcome measures were respiratory support, intensive care, and weight of <1000 g. Growth parameters were measured weekly or biweekly and at term age. Neuromotor development was assessed at term age. RESULTS: A total of 164 infants met the inclusion criteria (NIDCAP: N = 81; control: N = 83). In-hospital mortality rates were 8 (9.9%) of 81 infants in the NIDCAP group and 3 (3.6%) of 83 infants in the control group. No differences in mean days of respiratory support (NIDCAP: 13.9 days; control: 16.3 days) or mean days of intensive care (NIDCAP: 15.2 days; control: 17.0 days) were found. Short-term growth and neuromotor development at term age showed no differences, even with correction for the duration of the intervention. CONCLUSIONS: NIDCAP developmental care had no effect on respiratory support, days of intensive care, growth, or neuromotor development at term age.

Effects of basic developmental care on neonatal morbidity, neuromotor development, and growth at term age of infants who were born at <32 weeks.

OBJECTIVE: The goal of this study was to investigate the effect of basic elements of developmental care (incubator covers and positioning aids) on days of respiratory support and intensive care, growth, and neuromotor development at term age in infants who were born at <32 weeks' gestation. METHODS: Infants were randomly assigned within 48 hours of birth to the developmental care group or the standard care control group (no covers or nests). The intervention continued until the infant either was transferred to a regional hospital or was discharged from the hospital. Length, weight, and head circumference were measured (bi)weekly and at term age. Neuromotor development was defined as definitely abnormal (presence of a neonatal neurologic syndrome, such as apathy or hyperexcitability, hypotonia or hypertonia, hyporeflexia or hyperreflexia, hypokinesia or hyperkinesia, or a hemisyndrome), mildly abnormal (presence of only part of such a syndrome), or normal. RESULTS: A total of 192 infants were included (developmental care: 98; control: 94). Thirteen infants (developmental care: 7; control: 6) were excluded according to protocol (admitted for less than or died within the first 5 days: n = 12; taken out at parents' request: n = 1), which left a total of 179 infants who met inclusion criteria. In-hospital mortality was 12 (13.2%) of 91 in the developmental care group and 8 (9.1%) of 88 in the control group. There was no significant difference in the number of days of respiratory support, number of intensive care days, short-term growth, or neuromotor developmental outcome at term age between the developmental care and control groups. Duration of the intervention, whether only during the intensive care period or until hospital discharge, had no significant effect on outcome. CONCLUSIONS: Providing basic developmental care in the NICU had no effect on short-term physical and neurologic outcomes in infants who were born at <32 weeks' gestation.