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Obesity has been hypothesized to be associated with reduced moderate-to-vigorous physical activity (MVPA) and increased sedentary time (ST). It is important to assess whether, and the extent to which, levels of MVPA and ST are suboptimal among children and adolescents with obesity. The primary objective of this study was to examine accelerometer-measured time spent in MVPA and ST of children and adolescents with obesity, compared with MVPA recommendations, and with non-obese peers. An extensive search was carried out in Medline, Cochrane library, EMBASE, SPORTDiscus, and CINAHL, from 2000 to 2015. Study selection and appraisal: studies with accelerometer-measured MVPA and/or ST (at least 3 days and 6 h/day) in free-living obese children and adolescents (0 to 19 years) were included. Study quality was assessed formally. Meta-analyses were planned for all outcomes but were precluded due to the high levels of heterogeneity across studies. Therefore, narrative syntheses were employed for all the outcomes. Out of 1503 records, 26 studies were eligible (n = 14,739 participants; n = 3523 with obesity); 6/26 studies involved children aged 0 to 9 years and 18/26 involved adolescents aged 10.1 to19 years. In the participants with obesity, the time spent in MVPA was consistently below the recommended 60 min/day and ST was generally high regardless of the participant's age and gender. Comparison with controls suggested that the time spent in MVPA was significantly lower in children and adolescents with obesity, though differences were relatively small. Levels of MVPA in the obese and non-obese were consistently below recommendations. There were no marked differences in ST between obese and non-obese peers. MVPA in children and adolescents with obesity tends to be well below international recommendations. Substantial effort is likely to be required to achieve the recommended levels of MVPA among obese individuals in obesity treatment interventions. This systematic review has been registered on PROSPERO (International Database of Prospective Register Systematic Reviews; registration number CRD42015026882).

Moderate-to-vigorous physical activity (MVPA) and sedentary time (ST) are important for child and adolescent health. To examine habitual levels of accelerometer measured MVPA and ST in children and adolescents with chronic disease, and how these levels compare with healthy peers. Data sources: An extensive search was carried out in Medline, Cochrane library, EMBASE, SPORTDiscus and CINAHL from 2000-2017. Study selection: Studies with accelerometer-measured MVPA and/or ST (at least 3 days and 6 hours/day to provide estimates of habitual levels) in children 0-19 years of age with chronic diseases but without co-morbidities that would present major impediments to physical activity. In all cases patients were studied while well and clinically stable. Out of 1592 records, 25 studies were eligible, in four chronic disease categories: cardiovascular disease (7 studies), respiratory disease (7 studies), diabetes (8 studies), and malignancy (3 studies). Patient MVPA was generally below the recommended 60 min/day and ST generally high regardless of the disease condition. Comparison with healthy controls suggested no marked differences in MVPA between controls and patients with cardiovascular disease (1 study, n = 42) and type 1 diabetes (5 studies, n = 400; SMD -0.70, 95% CI -1.89 to 0.48, p = 0.25). In patients with respiratory disease, MVPA was lower in patients than controls (4 studies, n = 470; SMD -0.39, 95% CI -0.80, 0.02, p = 0.06). Meta-analysis indicated significantly lower MVPA in patients with malignancies than in the controls (2 studies, n = 90; SMD -2.2, 95% CI -4.08 to -0.26, p = 0.03). Time spent sedentary was significantly higher in patients in 4/10 studies compared with healthy control groups, significantly lower in 1 study, while 5 studies showed no significant group difference. MVPA in children/adolescents with chronic disease appear to be well below guideline recommendations, although comparable with activity levels of their healthy peers except for children with malignancies. Tailored and disease appropriate intervention strategies may be needed to increase MVPA and reduce ST in children and adolescents with chronic disease.

Summary Background The American Academy of Pediatrics recommends a permissive hypoxaemic target for an oxygen saturation of 90% for children with bronchiolitis, which is consistent with the WHO recommendations for targets in children with lower respiratory tract infections. No evidence exists to support this threshold. We aimed to assess whether the 90% or higher target for management of oxygen supplementation was equivalent to a normoxic 94% or higher target for infants admitted to hospital with viral bronchiolitis. Methods We did a parallel-group, randomised, controlled, equivalence trial of infants aged 6 weeks to 12 months of age with physician-diagnosed bronchiolitis newly admitted into eight paediatric hospital units in the UK (the Bronchiolitis of Infancy Discharge Study [BIDS]). A central computer randomly allocated (1:1) infants, in varying length blocks of four and six and without stratification, to be clipped to standard oximeters (patients treated with oxygen if pulse oxygen saturation [SpO2 ] <94%) or modified oximeters (displayed a measured value of 90% as 94%, therefore oxygen not given until SpO2 <90%). All parents, clinical staff, and outcome assessors were masked to allocation. The primary outcome was time to resolution of cough (prespecified equivalence limits of plus or minus 2 days) in the intention-to-treat population. This trial is registered with ISRCTN, number ISRCTN28405428. Findings Between Oct 3, and March 30, 2012, and Oct 1, and March 29, 2013, we randomly assigned 308 infants to standard oximeters and 307 infants to modified oximeters. Cough resolved by 15·0 days (median) in both groups (95% CI for difference −1 to 2) and so oxygen thresholds were equivalent. We recorded 35 serious adverse events in 32 infants in the standard care group and 25 serious adverse events in 24 infants in the modified care group. In the standard care group, eight infants transferred to a high-dependency unit, 23 were readmitted, and one had a prolonged hospital stay. In the modified care group, 12 infants were transferred to a high-dependency unit and 12 were readmitted to hospital. Recorded adverse events did not differ significantly. Interpretation Management of infants with bronchiolitis to an oxygen saturation target of 90% or higher is as safe and clinically effective as one of 94% or higher. Future research should assess the benefits and risks of different oxygen saturation targets in acute respiratory infection in older children, particularly in developing nations where resources are scarce. Funding National Institute for Health Research, Health Technology Assessment programme.

Randomized controlled trials (RCT) are required to test relationships between physical activity and cognition in children, but these must be informed by exploratory studies. This study aimed to inform future RCT by: conducting practical utility and reliability studies to identify appropriate cognitive outcome measures; piloting an RCT of a 10 week physical education (PE) intervention which involved 2 hours per week of aerobically intense PE compared to 2 hours of standard PE (control). 64 healthy children (mean age 6.2 yrs SD 0.3; 33 boys) recruited from 6 primary schools. Outcome measures were the Cambridge Neuropsychological Test Battery (CANTAB), the Attention Network Test (ANT), the Cognitive Assessment System (CAS) and the short form of the Connor's Parent Rating Scale (CPRS:S). Physical activity was measured habitually and during PE sessions using the Actigraph accelerometer. Test- retest intraclass correlations from CANTAB Spatial Span (r 0.51) and Spatial Working Memory Errors (0.59) and ANT Reaction Time (0.37) and ANT Accuracy (0.60) were significant, but low. Physical activity was significantly higher during intervention vs. control PE sessions (p < 0.0001). There were no significant differences between intervention and control group changes in CAS scores. Differences between intervention and control groups favoring the intervention were observed for CANTAB Spatial Span, CANTAB Spatial Working Memory Errors, and ANT Accuracy. The present study has identified practical and age-appropriate cognitive and behavioral outcome measures for future RCT, and identified that schools are willing to increase PE time. ISRCTN70853932 (http://www.controlled-trials.com).

Sitting time and breaks in sitting influence cardio-metabolic health. New monitors (e.g. activPAL™) may be more accurate for measurement of sitting time and breaks in sitting although how to optimize measurement accuracy is not yet clear. One important issue is the minimum sitting/upright period (MSUP) to define a new posture. Using the activPAL™, we investigated the effect of variations in MSUP on total sitting time and breaks in sitting, and also determined the criterion validity of different activPAL™ settings for both constructs. We varied setting of MSUP in 23 children (mean (SD) age 4.5 y (0.7)) who wore activPAL™ (24 hr/d) for 5-7 d. We first studied activPAL™ using the default setting of 10 s MSUP and then reduced this to 5 s, 2 s and 1 s. In a second study, in a convenience sample of 30 pre-school children (mean age 4.1 y (SD 0.5)) we validated the activPAL™ measures of sitting time and breaks in sitting at different MSUP settings against direct observation. Comparing settings of 10, 5, 2 and 1 s, there were no significant differences in sitting time (6.2 hr (1.0), 6.3 hr (1.0), 6.4 hr (1.0) and 6.3 hr (1.6), respectively) between settings but there were significant increases in the apparent number of breaks - (8(3), 14(2), 21(4) and 28 (6)/h) at 10, 5, 2 and 1 s settings, respectively. In comparison with direct observation, a 2 s setting had the smallest error relative to direct observation (95% limits of agreement: -14 to +17 sitting bouts/hr, mean difference 1.83, p = 0.2). With activPAL™, breaks in sitting, but not total sitting time, are highly sensitive to the setting of MSUP, with 2 s optimal for young children. The MSUP to define a new posture will need to be empirically determined if accurate measurements of number of breaks in sitting are to be obtained.

High levels of stress have been shown to predict the onset of asthma in children genetically at risk, and to correlate with higher asthma morbidity. Our study set out to examine whether stressful experiences actually provoke new exacerbations in children who already have asthma. A group of child patients with verified chronic asthma were prospectively followed up for 18 months. We used continuous monitoring of asthma by the use of diaries and daily peak-flow values, accompanied by repeated interview assessments of life events and long-term psychosocial experiences. The key measures included asthma exacerbations, severely negative life events, and chronic stressors. Severe events, both on their own and in conjunction with high chronic stress, significantly increased the risk of new asthma attacks. The effect of severe events without accompanying chronic stress involved a small delay; they had no effect within the first 2 weeks, but significantly increased the risk in the subsequent 4 weeks (odds ratio 1·71 [95% Cl 1·04–2·82], p≤0·05 for weeks 2–4 and 2·17 [1·32–3·57], p≤0·01 for weeks 4–6). When severe events occurred against the backdrop of high chronic stress, the risk increased sharply and almost immediately within the first fortnight (2·98 [1·20–7·38], p≤0–05). The overall attack frequency was affected by several factors, some related to asthma and some to child characteristics. Female sex, higher baseline illness severity, three or more attacks within 6 months, autumn to winter season, and parental smoking were all related to increased risk of new exacerbations; social class and chronic stress were not. Severely negative life events increase the risk of children's asthma attacks over the coming few weeks. This risk is magnified and brought forward in time if the child's life situation is also characterised by multiple chronic stressors.

IntroductionAsthma attacks are responsible for considerable morbidity and may be fatal. We aimed to identify and weight risk factors for asthma attacks in children (5–12 years) in order to inform and prioritise care.MethodsWe systematically searched six databases (May 2016; updated with forward citations January 2017) with no language/date restrictions. Two reviewers independently selected studies for inclusion, assessed study quality and extracted data. Heterogeneity precluded meta-analysis. Weighting was undertaken by an Expert Panel who independently assessed each variable for degree of risk and confidence in the assessment (based on study quality and size, effect sizes, biological plausibility and consistency of results) and then achieved consensus by discussion. Assessments were finally presented, discussed and agreed at a multidisciplinary workshop.ResultsFrom 16 109 records, we included 68 papers (28 cohort; 4 case-control; 36 cross-sectional studies). Previous asthma attacks were associated with greatly increased risk of attack (ORs between 2.0 and 4.1). Persistent symptoms (ORs between 1.4 and 7.8) and poor access to care (ORs between 1.2 and 2.3) were associated with moderately/greatly increased risk. A moderately increased risk was associated with suboptimal drug regimen, comorbid atopic/allergic disease, African-American ethnicity (USA), poverty and vitamin D deficiency. Environmental tobacco smoke exposure, younger age, obesity and low parental education were associated with slightly increased risk.DiscussionAssessment of the clinical and demographic features identified in this review may help clinicians to focus risk reduction management on the high-risk child. Population level factors may be used by health service planners and policymakers to target healthcare initiatives.Trial registration numberCRD42016037464.

  AbstractObjective: To test the ability of accelerometry to quantify sedentary behavior in 3- to 4-year-old children.Research Methods and Procedures: We developed a cut-off for accelerometry output (validation study) in 30 healthy 3 to 4 year olds, which provided highest sensitivity and specificity for the detection of sedentary behavior relative to a criterion method of measurement, direct observation using the children's physical activity form. We then cross-validated the cut-off in an independent sample of healthy 3 to 4 year olds (n = 52).Results: In the validation study, optimal sensitivity and specificity for the detection of sedentary behavior were obtained at an accelerometry output cut-off of <1100 counts/min. In the cross-validation, sensitivity was 83%: 438/528 inactive minutes were correctly classified. Specificity was 82%: 1251/1526 noninactive minutes were correctly classified using this cut-off.Discussion: Sedentary behavior can be quantified objectively in young children using accelerometry. This new technique could be considered for a wide variety of applications in the etiology, prevention, and treatment of childhood obesity.

NICE reports that, in its pilot study in seven practices, its algorithm could be completed in 55% of patients with suspected asthma; a diagnosis of asthma was confirmed in 25% of cases; with 20% reaching no diagnosis despite completing the algorithm. 9 BTS/SIGN used the same diagnostic test evidence, but also explicitly searched for pragmatic studies reporting evaluation of diagnostic programmes and, in discussion with the clinical guideline development group members, derived a 'good practice' algorithm. BTS/SIGN suggest that existing evidence of atopic status (blood eosinophils, skin prick testing, IgE) may influence the probablity of asthma, but agree with NICE that they should not be considered as 'diagnostic tests'; their key value may prove to be in establishing phenotypes of asthma or identifying triggers that may inform management. 11 Spirometry is positioned as pivotal by both guidelines, but both caution that it is not useful for ruling out asthma because the sensitivity is low, especially in primary care populations (only 27% of people diagnosed as having asthma in the NICE feasibility work had obstructive spirometry which is similar to the estimate in BTS/SIGN of 'a quarter having obstructive spirometry'). [...]the pattern of asthma in preschool children is heterogeneous and different from adults. Neither guideline addresses the issue of what to do with the child who is having frequent wheezing attacks treated with short courses of oral corticosteroids, but who has no interval asthma symptoms. 9 First-line preventer treatment in children under 5 with probable asthma and poor symptom control In young children with symptoms uncontrolled by intermittent reliever use in whom maintenance therapy is being considered, regular daily inhaled corticosteroid is the first-line preventer of choice although both BTS/SIGN and NICE acknowledge that the evidence base is limited.

  AbstractObjective: This study aimed to describe levels of physical activity in a representative sample of preschool children and to quantify tracking of activity over 1 year.Research Methods and Procedures: Physical activity (mean accelerometry counts/minute) was assessed over 3 days using the Computer Science and Applications accelerometer in 3- to 4-year-old children (n = 104; 52 boys; mean age, 3.7 ± 0.4 years). In 60 children (30 boys), measurements were repeated 1 year later.Results: Mean total activity at baseline was 777 ± 207 counts/minute in boys and 657 ± 172 counts/minute for girls; this gender difference was significant (p < 0.001). In the cross-sectional analysis, total activity was significantly positively related to age (r = 0.37, p = 0.007). In the sample followed up for 1 year, mean total activity was 849 ± 252. The longitudinal analysis confirmed that total physical activity increased over the 1-year period (paired Student's t test, p < 0.001). The tracking rank order correlation coefficient of total activity count over 1 year was r = 0.40 (p < 0.001).Discussion: This study suggests that total activity increases during the preschool period in Scottish children and that gender differences in total activity are present early in life. Tracking of total activity was only modest, but adequate assessment of tracking requires methodological research aimed at elucidating the biological meaning of accelerometer output.