Personal, environmental, and family factors of participation among young children.

OBJECTIVE: The purpose of this study is to assess the influences of environment, population characteristics, and service utilization on participation frequency and involvement in the home setting among children 0 to 5 years. METHOD: Data were collected from parents of 236 children (mean age 3 years and 5 months, SD = 1.30, girls = 152 and boys = 84) using a children's treatment centre in Ontario through an online survey. Two path models measuring home frequency and home involvement were assessed using structural equation modelling. The exogenous factors in the models included child's age, child's sex, child's complexity, number of environmental barriers, income, mother's participation, and service utilization. In addition to participation as the primary outcome, each model explored predictors of service utilization and mother's participation. RESULTS: The involvement model (R2  = 0.46) explained more variance than the frequency model (R2  = 0.33). Age (0.35, P < 0.001) and barriers (0.07, P = 0.001) predicted participation frequency in the home, χ2 (9) = 8.51, P < 0.4, root mean square error of approximation (RMSEA) = 0.00, comparative fit index (CFI) = 1.00. The home involvement model, χ2 (6) = 9.79, P < 0.13, RMSEA = 0.06, CFI = 0.97, showed that increasing age (0.09, P < 0.001), lower complexity (0.13, P = 0.001), and higher mother's participation (0.057, P = 0.001) were significantly related to higher participation. An increase in child's age or complexity significantly influenced service utilization across both models. Complexity reduced mother's participation in both the frequency and involvement models. CONCLUSIONS: This study is one of the first in Canada to examine participation of young children. The aggregation of each unit factor, particularly barriers and complexity, can accrue a large impact on the child's and mother's participation. The potential to mediate this impact by removing environmental barriers and promoting mother's participation merits further study.

The effectiveness of the Pathways and Resources for Engagement and Participation (PREP) intervention: improving participation of adolescents with physical disabilities.

AIM: This study examined the effectiveness of the Pathways and Resources for Engagement and Participation (PREP) intervention in improving the participation of adolescents in community-based activities. METHOD: Twenty-eight adolescents (14 males, 14 females), aged 12 to 18 years (mean 14y 6mo, SD 21.6mo) with moderate physical disabilities participated in a 12-week PREP intervention. An interrupted time series design with multiple baselines was employed, replicating the intervention effect across three chosen activities and all participants. An occupational therapist worked individually with adolescents and parents to identify and implement strategies to remove environmental barriers that impede participation in selected activities. Activity performance was repeatedly measured using the Canadian Occupational Performance Measure (COPM) at baseline, intervention, and follow-up (20wks). For each activity, the trajectory representing change in performance was analyzed descriptively. Segmented regression combined with a mixed-effects modeling approach was used to statistically estimate the overall effectiveness of the intervention within and across 79 activities. RESULTS: A statistically significant improvement (B=2.08, p<0.001) was observed across all activities, 59 per cent of which also indicated a clinically significant change of more than 2 points on the COPM scale. Levels of performance were maintained during follow-up with an additional increase of 0.66 points on the COPM scale (t=3.04, p=0.004). Intervention was most effective for males and those with a higher number of functional issues. INTERPRETATION: Findings illustrate that participation can be improved by changing the environment only. Such evidence further supports emerging therapeutic approaches that are activity-based, goal-oriented, and ecological in nature. WHAT THIS PAPER ADDS: Environment-based intervention strategies, guided by the Pathways and Resources for Engagement and Participation, are effective in improving and maintaining adolescent participation. Intervention was most effective for males and those with a higher number of functional issues. The study design serves as an example for future pragmatic studies accounting for individual-based changes and contexts.

Psychometric Evaluation of the Young Children's Participation and Environment Measure (YC-PEM) for use in Singapore.

AIMS: To estimate the psychometric properties of a culturally adapted version of the Young Children's Participation and Environment Measure (YC-PEM) for use among Singaporean families. METHODS: This is a prospective cohort study. Caregivers of 151 Singaporean children with (n = 83) and without (n = 68) developmental disabilities, between 0 and 7 years, completed the YC-PEM (Singapore) questionnaire with 3 participation scales (frequency, involvement, and change desired) and 1 environment scale for three settings: home, childcare/preschool, and community. Setting-specific estimates of internal consistency, test-retest reliability, and construct validity were obtained. RESULTS: Internal consistency estimates varied from .59 to .92 for the participation scales and .73 to .79 for the environment scale. Test-retest reliability estimates from the YC-PEM conducted on two occasions, 2-3 weeks apart, varied from .39 to .89 for the participation scales and from .65 to .80 for the environment scale. Moderate to large differences were found in participation and perceived environmental support between children with and without a disability. CONCLUSIONS: YC-PEM (Singapore) scales have adequate psychometric properties except for low internal consistency for the childcare/preschool participation frequency scale and low test-retest reliability for home participation frequency scale. The YC-PEM (Singapore) may be used for population-level studies involving young children with and without developmental disabilities.

Relationships between Adaptive Behaviours, Personal Factors, and Participation of Young Children.

AIM: To examine the extent to which personal factors (age, socioeconomic grouping, and preterm birth) and adaptive behaviour explain the participation patterns of young children. METHODS: 65 Children 2-5 years old with and without a history of preterm birth and no physical or intellectual disability were selected by convenience sampling from Galway University Hospital, Ireland. Interviews with parents were conducted using the Adaptive Behaviour Assessment System, Second Edition (ABAS-II) and the Assessment of Preschool Children's Participation (APCP). Linear regression models were used to identify associations between the ABAS-II scores, personal factors, and APCP scores for intensity and diversity of participation. RESULTS: Adaptive behaviour explained 21% of variance in intensity of play, 18% in intensity of Skill Development, 7% in intensity of Active Physical Recreation, and 6% in intensity of Social Activities controlling for age, preterm birth, and socioeconomic grouping. Age explained between 1% and 11% of variance in intensity of participation scores. Adapted behaviour (13%), Age (17%), and socioeconomic grouping (5%) explained a significant percentage of variance in diversity of participation controlling for the other variables. CONCLUSIONS: Adaptive behaviour had a unique contribution to children's intensity and diversity of participation, suggesting its importance.

Leisure participation-preference congruence of children with cerebral palsy: a Children's Assessment of Participation and Enjoyment International Network descriptive study.

AIM: To examine participation-preference congruence, regional differences in participation-preference congruence, and predictors of whether children with cerebral palsy participate in preferred activities. METHOD: The sample (n=236) included 148 males and 88 females aged 10 to 13 years, living in Victoria, Australia (n=110), Ontario (n=80), or Quebec (n=46), Canada. Ninety-nine (41.9%) were classed at Gross Motor Function Classification System (GMFCS) level I; 89 (37.7%) at GMFCS level II/III; and 48 (20.3%) at GMFCS level IV/V. Participants completed the Children's Assessment of Participation and Enjoyment and Preferences for Activity of Children questionnaires. Regional comparisons were performed using one-way analyses of variance and factors influencing participation-preference congruence were explored using multiple linear regression. RESULTS: The proportion of children doing non-preferred activities in each activity type was generally low (2-17%), with only one regional difference. Higher proportions were not doing preferred active physical (range 23.2-29.1% across regions), skill-based (range 21.7-27.9% across regions), and social activities (range 12.8-14.5% across regions). GMFCS level was the most important predictor associated with not doing preferred activities. INTERPRETATION: Children with cerebral palsy did not always participate in preferred active physical and skill-based activities. Understanding discrepancies between preferences and actual involvement may allow families and rehabilitation professionals to address participation barriers.

Measuring Participation of Children and Environmental Factors at Home, School, and in Community: Construct Validation of the Korean PEM-CY.

AIMS: To determine construct validity of the Korean Participation and Environment Measure for Children and Youth (KPEM-CY) in South Korea. METHODS: A total of 184 parents of children with (n = 80) and without disabilities (n = 104) aged 5 to 13 years completed the KPEM-CY. Construct validity was analyzed by assessing differences in the participation and environment scores for children with and without disabilities across age and gender. RESULTS: Validity of the KPEM-CY was supported by significant differences in participation and environmental factors for subgroups (p < .05). Children with disabilities participated less in typical activities and had more environmental barriers than those without disabilities across all settings. Parents of children with disabilities reported a higher level of desire to change their children's participation patterns. Similar participation patterns and environmental factors, which were influenced by interaction effects between disability and age, were confirmed at home and in the community. CONCLUSIONS: KPEM-CY is a valid measure to assess participation and environmental factors in home, school, and community settings for Korean children, aged 5-13 years, with and without disabilities.

Current Rehabilitation Practices for Children with Cerebral Palsy: Focus and Gaps.

AIMS: To describe the focus of therapy practices in occupational and physical therapy for school-aged children with cerebral palsy, and better understand whether it is congruent with recommended practices. METHODS: A Canada-wide Web-based survey was completed by 62 occupational and 61 physical therapists to identify problems, assessments, and treatment interventions for two case-based scenarios. Data were coded using the International Classification of Functioning, Disability and Health (ICF) definitions for "body functions and structure," "activity and participation," and "environment." RESULTS: Physical therapists, in comparison to occupational therapists, were more likely to select interventions classed in the "body functions and structure" category (34-42% and 18-20%, respectively). Both professions focused on "activity and participation" (34-61%) when identifying problems, assessing, and intervening; attention, however, was mainly directed towards task-oriented activities such as activities of daily living and mobility. Participation in leisure or community-based activities received less attention (2-15%). The environment received limited attention for problems and assessments (4-25%), though it was an important focus of intervention (19-37%). CONCLUSIONS: While body functions and structure are well-addressed, other ICF elements, specifically participation, are poorly integrated into practice. The emerging focus on the environment in therapy intervention, by modifying the context rather than changing aspects of the child, is consistent with current approaches and evidence. Knowledge translation implementation initiatives are recommended to bridge identified gaps.

CUB domain-containing protein 1 and the epidermal growth factor receptor cooperate to induce cell detachment.

BACKGROUND: While localized malignancies often respond to available therapies, most disseminated cancers are refractory. Novel approaches, therefore, are needed for the treatment of metastatic disease. CUB domain-containing protein1 (CDCP1) plays an important role in metastasis and drug resistance; the mechanism however, is poorly understood. METHODS: Breast cancer cell lines were engineered to stably express EGFR, CDCP1 or phosphorylation site mutants of CDCP1. These cell lines were used for immunoblot analysis or affinity purification followed by immunoblot analysis to assess protein phosphorylation and/or protein complex formation with CDCP1. Kinase activity was evaluated using phosphorylation site-specific antibodies and immunoblot analysis in in vitro kinase assays. Protein band excision and mass spectrometry was utilized to further identify proteins complexed with CDCP1 or ΔCDCP1, which is a mimetic of the cleaved form of CDCP1. Cell detachment was assessed using cell counting. RESULTS: This paper reports that CDCP1 forms ternary protein complexes with Src and EGFR, facilitating Src activation and Src-dependent EGFR transactivation. Importantly, we have discovered that a class of compounds termed Disulfide bond Disrupting Agents (DDAs) blocks CDCP1/EGFR/Src ternary complex formation and downstream signaling. CDCP1 and EGFR cooperate to induce detachment of breast cancer cells from the substratum and to disrupt adherens junctions. Analysis of CDCP1-containing complexes using proteomics techniques reveals that CDCP1 associates with several proteins involved in cell adhesion, including adherens junction and desmosomal cadherins, and cytoskeletal elements. CONCLUSIONS: Together, these results suggest that CDCP1 may facilitate loss of adhesion by promoting activation of EGFR and Src at sites of cell-cell and cell-substratum contact.

Developing a classification system of social communication functioning of preschool children with autism spectrum disorder.

AIM: Impairments in social communication are the hallmark of autism spectrum disorder (ASD). Operationalizing 'severity' in ASD has been challenging; thus, stratifying by functioning has not been possible. The purpose of this study is to describe the development of the Autism Classification System of Functioning: Social Communication (ACSF:SC) and to evaluate its consistency within and between parent and professional ratings. METHOD: (1) ACSF:SC development based on focus groups and surveys involving parents, educators, and clinicians familiar with preschoolers with ASD; and (2) evaluation of the intra- and interrater agreement of the ACSF:SC using weighted kappa (кw ). RESULTS: Seventy-six participants were involved in the development process. Core characteristics of social communication were ascertained: communicative intent; communicative skills and reciprocity; and impact of environment. Five ACSF:SC levels were created and content-validated across participants. Best capacity and typical performance agreement ratings varied as follows: intrarater agreement on 41 children was кw =0.61 to 0.69 for parents, and кw =0.71 to 0.95 for professionals; interrater agreement between professionals was кw =0.47 to 0.61, and between parents and professionals was кw =0.33 to 0.53. INTERPRETATION: Perspectives from parents and professionals informed ACSF:SC development, providing common descriptions of the levels of everyday communicative abilities of children with ASD to complement the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. Rater agreement demonstrates that the ACSF:SC can be used with acceptable consistency compared with other functional classification systems.

Establishing the Cultural Equivalence of the Young Children's Participation and Environment Measure (YC-PEM) for Use in Singapore.

AIMS: Establishing the cultural equivalence of clinical assessments is critical to ensuring culturally competent care. Developed in North America, the Young Children's Participation and Environment Measure (YC-PEM) is a caregiver questionnaire of participation in home, preschool, and community activities and perceptions of environmental impact on participation. The purpose of this study is to establish the cultural equivalence of YC-PEM content for use in Singapore. METHODS: We conducted semi-structured interviews with ten early childhood and healthcare providers and cognitive interviews with ten parents in Singapore to examine the relevance of original YC-PEM content (activities, environmental factors, item wording). Interviews were transcribed, summarized, and categorized according to item, semantic, conceptual, and operational dimensions of the Applied Cultural Framework that served as a decision-making guide to keep, modify, or delete the items. RESULTS: Providers and parents agreed on conceptual, item and semantic changes but less on operational changes. Significant changes were made to improve comprehension of the YC-PEM. CONCLUSIONS: Despite using the same language, the majority of the YC-PEM items needed modification to be relevant to the Singapore culture. Cultural adaptation of the YC-PEM is important because there are cultural differences in children's participation and their environments, as well as the way people understand words.

Comparative Effectiveness Research and Children With Cerebral Palsy: Identifying a Conceptual Framework and Specifying Measures.

PURPOSE: A step toward advancing research about rehabilitation service associated with positive outcomes for children with cerebral palsy is consensus about a conceptual framework and measures. METHODS: A Delphi process was used to establish consensus among clinicians and researchers in North America. RESULTS: Directors of large pediatric rehabilitation centers, clinicians from large hospitals, and researchers with expertise in outcomes participated (N = 18). Andersen's model of health care utilization framed outcomes: consumer satisfaction, activity, participation, quality of life, and pain. Measures agreed upon included Participation and Environment Measure for Children and Youth, Measure of Processes of Care, PEDI-CAT, KIDSCREEN-10, PROMIS Pediatric Pain Interference Scale, Visual Analog Scale for pain intensity, PROMIS Global Health Short Form, Family Environment Scale, Family Support Scale, and functional classification levels for gross motor, manual ability, and communication. CONCLUSIONS: Universal forms for documenting service use are needed. Findings inform clinicians and researchers concerned with outcome assessment.

Opening doors to participation of youth with physical disabilities: An intervention study.

BACKGROUND: While participation in leisure activities is beneficial to youth's health, little is known about effective intervention strategies to promote participation. PURPOSE: The aim of this study was to examine the effectiveness of environment-based interventions on participation of youth with physical disabilities. METHOD: Six adolescents ages 14 to 17 years participated in a 12-week intervention aimed at removing environmental barriers and coaching parents. An interrupted time series design was employed and a systematic replication of the intervention effect was examined across three individualized participation goals and across participants (17 goals overall). Goal performance was measured repeatedly using the Canadian Occupational Performance Measure and analyzed using visual inspection and a celeration line approach. FINDINGS: A clinically significant improvement in performance scores (M = 4.5, SD = 1.77) was observed across all 17 goals, and a statistically significant treatment effect was replicated in 13 goals (76%). IMPLICATIONS: Findings support the effectiveness of environment-based interventions in promoting youth participation, but larger studies are required.

Knowledge Translation from Research to Clinical Practice: Measuring Participation of Children with Disabilities.

This knowledge translation project was conducted to increase occupational therapy practitioners' awareness of the importance of measuring participation of children with disabilities. The Knowledge to Action process framework (KTA framework) guided knowledge translation via a web-based seminar (webinar) to practitioners working with children and educators teaching in occupational therapy programs in South Korea. Two hundred and seventy six views of the webinar were recorded within a month and 15 practitioners and 13 educators completed the online evaluation survey. The participants indicated that the webinar helped them understand the participation concept and its associated measures and raised awareness of practitioners' current use of measurement and intervention that do not focus on participation of children with disabilities. This project led practitioners and educators to realize the importance of measuring participation of children with disabilities and contributes to inform the importance of knowledge translation science to facilitate the evidence-based practice.

Cyclin-Dependent Kinase Inhibitors as Anticancer Therapeutics.

Cyclin-dependent kinases (CDKs) have been considered promising drug targets for a number of years, but most CDK inhibitors have failed rigorous clinical testing. Recent studies demonstrating clear anticancer efficacy and reduced toxicity of CDK4/6 inhibitors such as palbociclib and multi-CDK inhibitors such as dinaciclib have rejuvenated the field. Favorable results with palbociclib and its recent U.S. Food and Drug Administration approval demonstrate that CDK inhibitors with narrow selectivity profiles can have clinical utility for therapy based on individual tumor genetics. A brief overview of results obtained with ATP-competitive inhibitors such as palbociclib and dinaciclib is presented, followed by a compilation of new avenues that have been pursued toward the development of novel, non-ATP-competitive CDK inhibitors. These creative ways to develop CDK inhibitors are presented along with crystal structures of these agents complexed with CDK2 to highlight differences in their binding sites and mechanisms of action. The recent successes of CDK inhibitors in the clinic, combined with the potential for structure-based routes to the development of non-ATP-competitive CDK inhibitors, and evidence that CDK inhibitors may have use in suppressing chromosomal instability and in synthetic lethal drug combinations inspire optimism that CDK inhibitors will become important weapons in the fight against cancer.

Constitutive Cdk2 activity promotes aneuploidy while altering the spindle assembly and tetraploidy checkpoints.

The cell has many mechanisms for protecting the integrity of its genome. These mechanisms are often weakened or absent in many cancers, leading to high rates of chromosomal instability in tumors. Control of the cell cycle is crucial for the function of these checkpoints, and is frequently lost in cancers as well. Overexpression of Cyclin D1 in a large number of breast cancers causes overactivation of the cyclin-dependent kinases, including Cdk2. Constitutive Cdk2 activation through Cyclin D1 generates tumors in mice that are aneuploid and have many characteristics indicative of chromosomal instability. Expression of these complexes in the MCF10A cell line leads to retinoblastoma protein (Rb) hyperphosphorylation, a subsequent increase in proliferation rate, and increased expression of the spindle assembly checkpoint protein Mad2. This results in a strengthening of the spindle assembly checkpoint and renders cells more sensitive to the spindle poison paclitaxel. Constitutive Rb phosphorylation also causes a weakening of the p53-dependent tetraploidy checkpoint. Cells with overactive Cdk2 fail to arrest after mitotic slippage in the presence of paclitaxel or cytokinesis failure during treatment with cytochalasin-B, generating 8N populations. This additional increase in DNA content appears to further intensify the tetraploidy checkpoint in a step-wise manner. These polyploid cells are not viable long-term, either failing to undergo division or creating daughter cells that are unable to undergo subsequent division. This study raises intriguing questions about the treatment of tumors with overactive Cdk2.

The impact of preterm birth on participation in childhood occupation.

UNLABELLED: Outcome studies of premature babies have focused their assessments predominately on neurodevelopmental impairments without relating these deficits to the impact they have on a child's everyday life. This study aims to determine whether very 'preterm birth alone' impacts on a child's ability to participate in and carry out childhood activities. Forty-four former premature infants between 6 months and 5 years 6 months, born in Galway University Hospital, Ireland, without physical or intellectual disability, were compared with 51 age-matched term-born infants. Study infants had an average gestation of 29 weeks and birth weight of 1,145 g. Functional skills were assessed using the Adaptive Behavior Assessment Scale-II and the Assessment of Preschool Children's Participation. Premature infants had significantly lower mean scores in overall adaptive behaviour compared to term infants, regardless of whether chronological (difference = 13.6, 95% (CI) = [8.2, 19.1]) or corrected (difference = 6.6, 95% CI = [1.4, 11.8]) age was used. Premature infants had lower mean scores in conceptual, social and practical skills, but no difference was found between the groups in intensity or diversity of participation. CONCLUSION: Premature infants had significantly lower scores in adaptive behaviour than term infants. This measurable effect of preterm birth on 'childhood occupations' merits further investigation.

Psychometric properties of the Young Children's Participation and Environment Measure.

OBJECTIVE: To evaluate the psychometric properties of the newly developed Young Children's Participation and Environment Measure (YC-PEM). DESIGN: Cross-sectional study. SETTING: Data were collected online and by telephone. PARTICIPANTS: Convenience and snowball sampling methods were used to survey caregivers of children (N=395, comprising children with [n=93] and without [n=302] developmental disabilities and delays) between the ages of 0 and 5 years (mean age±SD, 35.33±20.29 mo) and residing in North America. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The YC-PEM includes 3 participation scales and 1 environment scale. Each scale is assessed across 3 settings: home, daycare/preschool, and community. Data were analyzed to derive estimates of internal consistency, test-retest reliability, and construct validity. RESULTS: Internal consistency ranged from .68 to .96 and .92 to .96 for the participation and environment scales, respectively. Test-retest reliability (2-4 wk) ranged from .31 to .93 for participation scales and from .91 to .94 for the environment scale. One of 3 participation scales and the environment scale demonstrated significant group differences by disability status across all 3 settings, and all 4 scales discriminated between disability groups for the daycare/preschool setting. The participation scales exhibited small to moderate positive associations with functional performance scores. CONCLUSIONS: Results lend initial support for the use of the YC-PEM in research to assess the participation of young children with disabilities and delays in terms of (1) home, daycare/preschool, and community participation patterns; (2) perceived environmental supports and barriers to participation; and (3) activity-specific parent strategies to promote participation.

"Do-Live-Well": a Canadian framework for promoting occupation, health, and well-being.

BACKGROUND: Occupational therapists can bring a unique and valuable perspective to the national dialogue on health promotion. Current approaches have a narrow focus on diet and exercise; a broader focus on occupation has the potential to enrich understanding regarding forces that contribute to health and well-being. PURPOSE: A new "Do-Live-Well" framework will be presented that is grounded in evidence regarding the links between what people do every day and their health and well-being. KEY ISSUES: Elements of the framework include eight different dimensions of experience and five key activity patterns that impact health and well-being outcomes. Personal and social forces that shape activity engagement also affect the links to health and well-being. IMPLICATIONS: The framework is designed to facilitate individual reflection, community advocacy, and system-level dialogue about the impact of day-to-day occupations on the health and well-being of Canadians.

Improving the participation of youth with physical disabilities in community activities: An interrupted time series design.

BACKGROUND/AIM: Youth with physical disabilities experience restrictions to participation in community-based leisure activities; however, there is little evidence about how to improve their involvement. This study examined whether an intervention to remove environmental barriers and develop strategies using a coaching approach improved youth participation in leisure activities. METHODS: An Interrupted Time Series design was employed, where replication of the intervention effect was examined across individualised participation goals and across participants. Six adolescents with a physical disability participated in a 12-week intervention. An occupational therapist worked with each youth and his/her family to set three leisure goals based on problems identified using the Canadian Occupational Performance Measure (COPM). A coaching approach was used to collaboratively identify and implement strategies to remove environmental barriers. Interventions for each goal were introduced at different time points. Outcomes were evaluated using the COPM. RESULTS: Improvements in COPM performance scores were clinically significant for 83% of the identified activities; an average change of 4.5 points in the performance scale (SD = 1.95) was observed. Statistical analysis using the celeration line demonstrated that the proportion of data points falling above the line increased in the intervention phase for 94% of the activities, indicating a significant treatment effect. CONCLUSIONS: This study is the first to examine an intervention aimed at increasing leisure participation by changing only the environment. The results indicate that environment-focussed interventions are feasible and effective in promoting youth participation. Such findings can inform the design of a larger study and guide occupational therapy practice.

The mediating role of the environment in explaining participation of children and youth with and without disabilities across home, school, and community.

OBJECTIVE: To test the effect of personal and environmental factors on children's participation across 3 different settings (home, school, community); to ascertain the interrelations between these factors; and to propose and test 3 models, 1 for each setting, using structural equation modeling. DESIGN: Survey, cross-sectional study, and model testing. SETTING: Web-based measures were completed by parents residing in North America in their home/community. PARTICIPANTS: Parents (N=576) of children and youth with and without disabilities, (n=282 and n=294, respectively), ages 5 to 17 years (mean age, 11y 2mo), completed the Participation and Environment Measure for Children and Youth (PEM-CY). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The PEM-CY measured levels of participation frequency and involvement, as well as environmental barriers and supports of participation, in each of the following 3 settings: home, school, and community. Information about the child's health condition and functional issues was also collected. RESULTS: All 3 models fit the data well (comparative fit index, .89-.97) and explained 50% to 64% of the variance of participation frequency and involvement. Environmental barriers and supports served as significant mediators between child/personal factors (income, health condition, functional issues) and participation outcomes, across all models. The effect of the environment was most pronounced, however, in the community setting. CONCLUSIONS: Our findings highlight the unique role of the environment in explaining children's participation across different settings and, therefore, support the development of interventions targeting modifiable environmental factors.