Health-related Outcomes In Children Research Articles

Pupil Voices: Review of Factors Influencing Pupil Participation in Primary School Physical Activity

ABSTRACT Context Because the purpose of school-based physical activity (PA) interventions is to improve academic and/or health-related outcomes for children, their views must be considered for such programs to be successful. To inform the development of acceptable initiatives, a need exists to examine and synthesize pupil perspectives. Objective This review explores what is known about primary-aged pupils’ perspectives on school-based PA and qualitatively synthesizes the factors that influence pupil participation. Design This rapid qualitative review was conducted systematically and followed the Enhancing Transparency in Reporting the Synthesis of Qualitative Research (ENTREQ) guidelines. Eligibility Criteria Peer-reviewed articles published in the English language between January 2013 and April 2023 that reported qualitative data on primary school pupil participation in school-based PA were included. Study Selection Databases searched were Medline (Web of Science), ERIC (Education Collection-ProQuest), and EBSCO (Academic Search Complete, Education Source, ERIC, APA PsycArticles, APA PsycInfo, SportDiscus, CINAHL complete, Medline Full Text, Humanities Source Ultimate). Twenty-one articles that included qualitative evaluations of pupil participation in school-based PA from the pupil perspective were included. Main Outcome Measures The main outcome measured was pupil perceptions of factors that influence their participation in school-based PA. Results Ten themes emerged from the pupil data. The most prevalent was fun and enjoyment, followed by perceived health benefits, social interaction, and perceived academic benefits. Autonomy, appropriate level of challenge, perceived motor competence, school culture and environment, outdoor play, and influence of teachers were also identified. Conclusion To promote participation in PA, schools must support autonomy with developmentally appropriate equipment and space to facilitate physically active games. Positive and encouraging adults must maintain socially safe environments where pupils can be active with their friends. Physical education must be highly regarded, and pupils should have multiple opportunities to engage in PA throughout the school day.

Impacts of compounding drought and heatwave events on child mental health: insights from a spatial clustering analysis

BackgroundConcurrent heatwave and drought events may have larger health impacts than each event separately; however, no US-based studies have examined differential mental health impacts of compound drought and heatwave events in pediatric populations.ObjectiveTo examine the spatial patterns of mood disorders and suicide-related emergency department (ED) visits in children during heatwave, drought, and compound heatwave and drought events. We tested whether the occurrence of compound heatwave and drought events have a synergistic (multiplicative) effect on the risk of mental health related outcomes in children as compared to the additive effect of each individual climate hazard. Lastly, we identified household and community-level determinants of geographic variability of high psychiatric burden.MethodsDaily counts of psychiatric ED visits in North Carolina from 2016 to 2019 (May to Sept) for pediatric populations were aggregated at the county scale. Bernoulli cluster analyses identified high-risk spatial clusters of psychiatric morbidity during heatwave, drought, or compound heatwave and drought periods. Multivariate adaptive regression models examined the individual importance of household and community-level determinants in predicting high-risk clustering of mood disorders or suicidality across the three climate threats.ResultsResults showed significant spatial clustering of suicide and mood disorder risks in children during heatwave, drought, and compound event periods. Periods of drought were associated with the highest likelihood of spatial clustering for suicide and mood disorders, where the risk of an ED visit was 4.48 and 6.32 times higher, respectively, compared to non-drought periods. Compounding events were associated with a threefold increase in both suicide and mood disorder-related ED visits. Community and household vulnerability factors that most contributed to spatial clustering varied across climate hazards, but consistent determinants included residential segregation, green space availability, low English proficiency, overcrowding, no broadband access, no vehicle access, housing vacancy, and availability of housing units.ConclusionFindings advance understanding on the locations of vulnerable pediatric populations who are disproportionately exposed to compounding climate stressors and identify community resilience factors to target in public health adaptation strategies.

Multivariable reference centiles for maximum grip strength in childhood to young adults

ObjectivesMaximum grip strength (mGS) is a useful predictor of health-related outcomes in children and adults. The aim of the study was to generate sex- and age-adjusted reference centiles for mGS for children, adolescents and young adults, while adjusting for body height and body mass index (BMI).MethodsA retrospective analysis of longitudinal data from children and young adults participating in the DOrtmund Nutritional and Anthropometric Longitudinally Designed (DONALD) study (single center, open cohort study) from 2004 to 2022 was conducted. To generate sex-, age-, height- and BMI-adjusted reference centiles, a new algorithm combining multiple linear regression and the LMS method was conducted.ResultsOverall, 3325 measurements of mGS of 465 females and 511 males were eligible. The mean age at measurement of females was 12.6 ± 3.9 years, mean age of males was 12.4 ± 4.7 years. The median of number of repeated measurements per individual was 3 (range 1–8). The mGS was significantly (p < 0.001) correlated to body height and BMI (r = 0.303–0.432). Additional reference centiles for the change of z-scores of mGS were generated for children and young adults from 8 to 20 years.ConclusionsWe proposed to evaluate mGS in children, adolescents and young adults with the presented reference centiles adjusted to sex, age, height and BMI. The method presented may also be applicable to other biological variables that depend more than just on sex and age. For the first time, also reference centiles to assess the change of mGS in repeated measurements were presented.

Psychosocial Outcomes of Parents of Children with Hirschsprung Disease Beyond Early Childhood

PurposeThe lifelong impact of Hirschsprung disease (HD) upon children and their families is increasingly well recognized. Parental psychosocial wellbeing and family functioning are determinants of psychological and health-related outcomes in children with chronic conditions. We performed a cross-sectional cohort study to evaluate the psychosocial functioning of parents/caregivers of children with HD, beyond early childhood. MethodsParents/caregivers of children with HD, aged 4–14 years, managed at a tertiary pediatric surgical center were surveyed. Parent psychosocial outcomes, including adjustment to illness and family response, were assessed using four validated measures: Family Management Measure (FaMM); Parent Experience of Child Illness (PECI); Patient Reported Outcomes Measurement Information System (PROMISR) anxiety; and PROMISR depression. The Pediatric Quality of Life Inventory (PedsQL) was administered to assess child quality of life (proxy-report). ResultsForty parents (mean age 38.7 ± 5.6 years) of children with HD (mean age 8.0 ± 2.5) participated. Parents expressed greater long-term uncertainty (PECI) and poorer perceived condition management ability (FaMM) than comparator chronic disease cohorts. Other scores for parental adjustment to their child's condition (PECI) and family response (FaMM) were comparable to reference cohorts. Symptoms of anxiety and depression were prevalent in our cohort (52.5 % and 42.5 % respectively); however, the proportion with moderate - severe PROMISR anxiety (χ2 = 2.50, p = 0.114) and depression (χ2 = 0.156, p = 0.693) scores did not significantly differ from the expected population distribution. Proxy-reported child quality of life (PedsQL) was significantly reduced relative to healthy children (p = 0.0003), but comparable to those with physical health problems with special healthcare needs (p = 0.624). ConclusionsParents of children with HD experience long-term uncertainty and have poorer perceived condition management ability than parents of children with other chronic childhood illnesses. This work highlights the importance of targeted parental education and support beyond primary surgical management, and provides a benchmark for this cohort, against which subsequent intervention-based studies may be assessed. Level of evidenceII.

Effects of Mind-Body Exercises on Health-related Outcomes in Children and Adolescents with Autism Spectrum Disorder: A Systematic Review

Effects of Mind-Body Exercises on Health-related Outcomes in Children and Adolescents with Autism Spectrum Disorder: A Systematic Review

MICRONUTRIENT STATUS AND ENERGY INTAKE IN MODERATE ACUTE MALNOURISHED CHILDREN AFTER INTAKE OF HIGH ENERGY NUTRITIONAL SUPPLEMENTS FOR FOUR WEEKS: A RANDOMIZED CONTROLLED STUDY

Background: Undernutrition including micronutrient deficiency results in adverse health-related outcomes in children of low-medium income countries. This study aims to explore the effect of four weeks of Lipid-based nutritional supplement (LNS) on energy intake, anthropometry and micronutrient status in moderate acute malnourished children. Methods Thirty-four children with mean age 7.08±1.47 years and a BMI Z score between -2 and -3 SDS were randomized into LNS and Placebo groups in a single blind randomized control trial. Energy intake, fasting blood samples, and anthropometric measurements were obtained prior to and after four weeks of LNS (535 kcal) or Placebo (92kcal) supplementation in addition to their habitual dietary intake. Results: During four weeks of supplementation, energy intake (kcal) [(611±155) to (987±224), p&lt;0.001)], weight (kg) [(17.5±2.83) to (18.1±3.24), p&lt; 0.001], mid-upper arm circumference (cm) [(14.8±0.91) to (15.1±0.84), p=0.005)] and BMI (kg/m2) [(12.9±0.33) to (13.3±0.45), p=0.002] was significantly improved in the LNS group compared to Placebo. A significant increase in hemoglobin (g/ml) [(12.2±1.14) to (13.7±1.69), p&lt;0.01] and iron levels (µg/dl) [(0.36±0.09) to (0.67±0.20), p&lt;0.001] were observed in the LNS group. No significant differences were detected in the copper and zinc levels. Conclusion: Lipid-based nutritional supplement is effective in improving energy intake, nutritional outcomes and iron but not copper and zinc. The trial was registered at www.isrctn.com under reference: ISRCTN147181521.

A Computer-Based Interactive Narrative and a Serious Game for Children With Asthma: Development and Content Validity Analysis.

BackgroundNonadherence to medications, failure to prevent exposure to asthma triggers, lack of knowledge about using medications, and fixed mindsets contribute to poor asthma control in children. Digital learning could provide a new strategy for improving health-related outcomes in children with asthma.ObjectiveThe aim of this study is to develop and design a digital educational program, titled Module of Inhaler and Asthma Triggers for Children (MIRACLE), for Indonesian children with asthma. The program comprises an interactive narrative and a serious game. It was proposed to increase the understanding of asthma self-management, instruct on proper inhaler techniques, improve asthma control, and promote a growth mindset for children with asthma.MethodsTwo phases of research were conducted to develop the program. In the first phase, a literature search and two rounds of the Delphi technique were conducted to obtain agreement from an expert panel regarding elements of asthma self-management and the design of interactive narratives and a serious game. The expert panel item statements were evaluated using the content validity index (CVI). In the second phase, the SERES framework, Norma Engaging Multimedia Design, and Psychological Theory of Growth Mindset were applied to create a storyline, learn objectives, and game challenges.ResultsIn the first phase, 40 experts were invited to participate in Delphi round 1. Forty responses were collected to generate 38 item statements that consisted of part 1, elements of asthma self-management (25 items), and part 2, design of an interactive narrative and a serious game (13 items); 38 experts were involved in Delphi round 2. In total, 24 statements in part 1 and 13 items in part 2 had item-CVI values >0.80. The average CVI was 0.9, which was considered acceptable. Four narrative plots and five game sessions were developed during the second phase. Challenges with the scenario, scoring, and feedback on asthma difficulties were designed to promote a growth mindset for learners.ConclusionsWe developed a culture-specific, computer-based asthma program containing an interactive narrative and a serious game to deliver asthma self-management and promote a growth mindset among Indonesian children.

Effects of Classroom Active Desks on Children and Adolescents' Physical Activity, Sedentary Behavior, Academic Achievements and Overall Health: A Systematic Review.

The purpose of this systematic review was to examine the effects of active desks in the school setting on sedentary behavior, physical activity, academic achievements and overall health among children and adolescents aged 5–17 years. A systematic literature search was conducted using five databases until October 2020. Twenty-three studies were included. Studies reported an increase of around 36% in energy expenditure for cycling desks and between 15% and 27.7% for upright active desks. Children increased inhibitory control and selective attention capacity while using cycling desks. A heterogeneous quality of design and of results were observed limiting comparisons and conclusions for each active desk. Despite the lack of strong methodology for the included studies, active desks appear to be a promising intervention in classrooms to improve health-related outcomes in children aged 5–17 years. Due to weak methodology, future studies with stronger study designs and methodology are needed to better inform policy and practice about the role of classroom active desks on health-related outcomes in children and adolescents.

Of Major Complication Types, Only Deep Infections After Spinal Fusion Are Associated With Worse Health-related Outcomes in Children With Cerebral Palsy.

Retrospective review. The aim of this study was to determine whether major postoperative complications ("complications") are associated with 2-year improvements in Caregiver Priorities and Child Health Index of Life with Disabilities (CPCHILD) scores after scoliosis surgery, and whether complications and preoperative characteristics predict 2-year improvements in CPCHILD Total score. Spinal arthrodesis can halt the progression of spinal deformity in patients with cerebral palsy (CP)-related scoliosis. However, these patients are prone to postoperative complications. Using a multicenter CP registry, we identified 222 patients aged ≤21 years who underwent spinal fusion from 2008 to 2015 and had ≥2-year follow-up. We compared CPCHILD score improvement between 71 patients who had 1 or more complications ("complications group") versus 151 who did not ("no-complications group"). Complications were deep infections, thromboembolic events, and cardiopulmonary, gastrointestinal, and neurologic complications. Multiple linear regression was used to identify predictors of 2-year postoperative CPCHILD score improvement (alpha = 0.05). At 2-year follow-up, the complications group had similar mean improvement in CPCHILD score across all domains compared with the no-complications group (P > 0.05). When stratifying by complication type, deep infection was associated with less improvement in CPCHILD Comfort and Emotions (P = 0.02), Quality of Life (P < 0.01), and Total (P = 0.04) scores. When controlling for Gross Motor Function Classification System subcategory, age, and body mass index, only preoperative CPCHILD Total score and postoperative deep infection (F[4, 176] = 14; P < 0.0001; R = 0.24) predicted 2-year improvement in CPCHILD Total score. Higher preoperative Total score and postoperative deep infection independently predicted less improvement in Total score. Postoperative deep infection and higher preoperative CPCHILD Total score independently predicted less improvement in CPCHILD Total score. Other major postoperative complications were not associated with differences in 2-year postoperative improvements in CPCHILD scores across all domains. 3.

What do we know about travel for children with special health care needs? A review of the literature.

Children travel with their families, including children with chronic illness. We know that adults with chronic illness who travel are more likely than their healthy peers to become sick while traveling. A review of the literature was undertaken to identify what is known about traveling with children with special health care needs and to identify gaps in our knowledge. An Online search of the PubMed, CINAHL and Google databases of English language literature was conducted June 2016, October 2017, June 2018 and April 2019 using the terms children and travel, air travel, travel health, disabled child, children with special healthcare needs, parents of disabled children, vacations, recreation, international, wheelchairs, planning techniques, asthma, diabetes, altitude, cystic fibrosis, inflammatory bowel disease, sickle cell disease, depression, food allergies, Attention Deficit Hyperactivity Disorder (ADHD), and seizures. The search was limited to years 2000-2019. A secondary search of relevant articles was conducted using the reference sections of articles identified in the primary search. 185 papers were examined for travel health related outcomes for children and adults with chronic diseases. Articles were excluded if they addressed the educational needs of students with disabilities traveling abroad, did not directly address travel health (e.g travel skills, travel itineraries), contained outdated policy statements, or were case reports of a single patient. The remaining 84 papers were organized and reviewed by organ systems. The articles were primarily descriptive and did not lend themselves to a systematic review. Children traveling with chronic and complex health conditions are a heterogeneous group of vulnerable travelers. Closing the knowledge gap about how to best help these travelers requires a multipronged approach. Research is urgently needed to identify best practices for five of the most common chronic childhood diseases: asthma, depression, ADHD, food allergies and autism. For less common illnesses, ones typically cared for in specialty clinics, expert consensus opinion and multi-center studies are needed. Families and disease advocacy societies should be included in the research as they may have already identified the most pressing travel-related health concerns and solutions for these problems.

Eating Behaviors of Preschool-Aged Children – Gender-Linked Differences

A growing popularity in the consumption of foods with low nutritional value is increasing amongst the preschool age groups worldwide, which is partially responsible for the increase of childhood obesity rates globally. Thus, it is vital to examine the eating behavior of preschool aged children, as these are known to effect the daily energy intake. On the contrary, gender differences could possibly also influence the food intake and therefore health-related outcomes in children. In order to investigate the relationship between the children’s eating behavior and their gender, a survey was conducted amongst the parents of children aged between 3-7 in Hungary, which included Wardle et al.’s (2001a) 35-item instrument, the Children’s Eating Behavior Questionnaire, together with questions concerning possible food allergies and demographics. The sample of size N=365 was then analyzed using SPSS via the INDSCAL method. The initial creators of the Child Eating Behavior Questionnaire found only one gender difference, namely that the incidence of eating fussiness was slightly higher in boys, the findings of the current study were able to verify this result together with other dissimilarities. The findings indicate that other eating behaviors can be linked to gender, including that girls’ desires to drink, which is generally higher than that of boys and that boys tend to eat slower than girls. Boys also lean towards emotional undereating, while girls have a tendency towards emotional overeating. The information above can be of great use to marketers in the food and beverage industry as well as the healthcare industry. JEL Codes: I12, M31

Protocol for the EMPHASIS study; epigenetic mechanisms linking maternal pre-conceptional nutrition and children\u2019s health in India and Sub-Saharan Africa

BackgroundAnimal studies have shown that nutritional exposures during pregnancy can modify epigenetic marks regulating fetal development and susceptibility to later disease, providing a plausible mechanism to explain the developmental origins of health and disease. Human observational studies have shown that maternal peri-conceptional diet predicts DNA methylation in offspring. However, a causal pathway from maternal diet, through changes in DNA methylation, to later health outcomes has yet to be established. The EMPHASIS study (Epigenetic Mechanisms linking Pre-conceptional nutrition and Health Assessed in India and Sub-Saharan Africa, ISRCTN14266771) will investigate epigenetically mediated links between peri-conceptional nutrition and health-related outcomes in children whose mothers participated in two randomized controlled trials of micronutrient supplementation before and during pregnancy.MethodsThe original trials were the Mumbai Maternal Nutrition Project (MMNP, ISRCTN62811278) in which Indian women were offered a daily snack made from micronutrient-rich foods or low-micronutrient foods (controls), and the Peri-conceptional Multiple Micronutrient Supplementation Trial (PMMST, ISRCTN13687662) in rural Gambia, in which women were offered a daily multiple micronutrient (UNIMMAP) tablet or placebo. In the EMPHASIS study, DNA methylation will be analysed in the children of these women (~1100 children aged 5–7 y in MMNP and 298 children aged 7–9 y in PMMST). Cohort-specific and cross-cohort effects will be explored. Differences in DNA methylation between allocation groups will be identified using the Illumina Infinium MethylationEPIC array, and by pyrosequencing top hits and selected candidate loci. Associations will be analysed between DNA methylation and health-related phenotypic outcomes, including size at birth, and children’s post-natal growth, body composition, skeletal development, cardio-metabolic risk markers (blood pressure, serum lipids, plasma glucose and insulin) and cognitive function. Pathways analysis will be used to test for enrichment of nutrition-sensitive loci in biological pathways. Causal mechanisms for nutrition-methylation-phenotype associations will be explored using Mendelian Randomization. Associations between methylation unrelated to supplementation and phenotypes will also be analysed.ConclusionThe study will increase understanding of the epigenetic mechanisms underpinning the long-term impact of maternal nutrition on offspring health. It will potentially lead to better nutritional interventions for mothers preparing for pregnancy, and to identification of early life biomarkers of later disease risk.

Does neighbourhood social capital aid in levelling the social gradient in the health and well-being of children and adolescents? A literature review

BackgroundAlthough most countries in the European Union are richer and healthier than ever, health inequalities remain an important public health challenge. Health-related problems and premature death have disproportionately been reported in disadvantaged neighbourhoods. Neighbourhood social capital is believed to influence the association between neighbourhood deprivation and health in children and adolescents, making it a potentially interesting concept for policymakers.MethodsThis study aims to review the role of social capital in health inequalities and the social gradient in health and well-being of children and adolescents. A systematic review of published quantitative literature was conducted, focussing on (1) the mediating role of neighbourhood social capital in the relationship between socio-economic status (SES) and health-related outcomes in children and adolescents and (2) the interaction between neighbourhood social capital and socio-economic characteristics in relation to health-related outcomes in children and adolescents. Three electronic databases were searched. Studies executed between 1 January 1990 and 1 September 2011 in Western countries (USA, New Zealand, Australia and Europe) that included a health-related outcome in children or adolescents and a variable that measured neighbourhood social capital were included.ResultsEight studies met the inclusion criteria for the review. The findings are mixed. Only two of five studies confirmed that neighbourhood social capital mediates the association between neighbourhood deprivation and health and well-being in adolescents. Furthermore, two studies found a significant interaction between neighbourhood socio-economic factors and neighbourhood social capital, which indicates that neighbourhood social capital is especially beneficial for children who reside in deprived neighbourhoods. However, two other studies did not find a significant interaction between SES and neighbourhood social capital. Due to the broad range of studied health-related outcomes, the different operationalisations of neighbourhood social capital and the conceptual overlap between measures of SES and social capital in some studies, the factors that explain these differences in findings remain unclear.ConclusionsAlthough the findings of this study should be interpreted with caution, the results suggest that neighbourhood social capital might play a role in the health gradient among children and adolescents. However, only two of the included studies were conducted in Europe. Furthermore, some studies focussed on specific populations and minority groups. To formulate relevant European policy recommendations, further European-focussed research on this issue is needed.

Health-related outcomes in children after critical illness*

Division of Pediatric Critical Care Medicine, Weill Cornell Medical College New York, NY, Barnabas Health West Orange, NJ; and Basic Sciences, Medicine, and Pediatrics Virginia Tech-Carilion School of Medicine, Roanoke, VA *See also p. 387. Listen to the Critical Care podcasts for an in-depth interview on this article. Visit www.sccm.org/iCriticalCare or search “SCCM” at iTunes. The authors have not disclosed any potential conflicts of interest.

The effectiveness of music in pediatric healthcare: a systematic review of randomized controlled trials.

The aim of this study was to systematically review the effectiveness of music on pediatric health-related outcomes. Five electronic databases were searched for randomized controlled/crossover trial designs published between 1984 and 2009. Eligible studies used music as a therapy or intervention, included participants 1 to 18 years, and focused on at least one health-related outcome (with the exclusion of procedural pain). Seventeen studies met the inclusion criteria. Quantitative synthesis was hampered by an inability to aggregate data arising from heterogeneity of interventions, outcomes and measurement tools. Qualitative synthesis revealed significant improvements in one or more health outcomes within four of seven trials involving children with learning and developmental disorders; two of three trials involving children experiencing stressful life events; and four of five trials involving children with acute and/or chronic physical illness. No significant effects were found for two trials involving children with mood disorders and related psychopathology. These findings offer limited qualitative evidence to support the effectiveness of music on health-related outcomes for children and adolescents with clinical diagnoses. Recommendations for establishing a consensus on research priorities and addressing methodological limitations are put forth to support the continued advancement of this popular intervention.

Effectiveness of parent-centred interventions for the prevention and treatment of childhood overweight and obesity in community settings: A Systematic Review.

Review Question/ Objective The objective of this review is to identify the effectiveness of parent-centred interventions implemented in the community setting, in modifying eating and physical activity behaviours or weight-related outcomes of children. Criteria for inclusion Types of Participants This review will consider studies that include children of pre-school, primary and secondary school age and/or their parents aged >18 years. Types of interventions Interventions of interest are implemented in a community setting including, but not limited to; pre-schools (outside of curriculum), schools (non-curricular, before- and after-school), home based community centres and community camps, with an aim of improving eating and physical activity behaviours and/ or overweight/obesity outcome measures. Interventions conducted at pre-schools and schools must be conducted outside of those school curriculums and must be resourced separately. Types of Outcomes This review will consider studies that include the following outcome measures for children and / or their parents: i) Overweight/obesity related outcomes: weight (kg), % body weight lost, BMI, waist circumference (cm) ii) Eating behaviour outcomes: fruit and vegetable intake, macronutrient composition (eg fat intake per day), core food groups, diet quality iii) Physical activity behaviour outcomes: steps per day, time spent in activity, energy expenditure iv) Sedentary behaviour outcomes and constructs: Time spent in non-educational, small screen recreation (eg TV, computer, hand held electronic games.)

Estimating adjusted prevalence ratio in clustered cross-sectional epidemiological data

BackgroundMany epidemiologic studies report the odds ratio as a measure of association for cross-sectional studies with common outcomes. In such cases, the prevalence ratios may not be inferred from the estimated odds ratios. This paper overviews the most commonly used procedures to obtain adjusted prevalence ratios and extends the discussion to the analysis of clustered cross-sectional studies.MethodsPrevalence ratios(PR) were estimated using logistic models with random effects. Their 95% confidence intervals were obtained using delta method and clustered bootstrap. The performance of these approaches was evaluated through simulation studies. Using data from two studies with health-related outcomes in children, we discuss the interpretation of the measures of association and their implications.ResultsThe results from data analysis highlighted major differences between estimated OR and PR. Results from simulation studies indicate an improved performance of delta method compared to bootstrap when there are small number of clusters.ConclusionWe recommend the use of logistic model with random effects for analysis of clustered data. The choice of method to estimate confidence intervals for PR (delta or bootstrap method) should be based on study design.