Participation is a critical concept for children's health and their interaction with the context in which they live. Recently, participation has been understood as a family of constructs that includes attendance (frequency of activities carried out) and involvement (engagement, persistence, social connection, affection, and personal preferences). Young children with disabilities are at risk of experiencing participation restriction, which reinforces the importance of incorporating participation assessment measures into child rehabilitation. In this sense, the Participation and Environment Measure - Young Children (YC-PEM) stands out, an instrument developed based on the model of the International Classification of Functioning, Disability and Health (ICF), centered on the perception of the caregiver, to assess the participation and environment of young children, with or without disabilities.

To establish the initial psychometric properties of the YC-PEM translated into Brazilian Portuguese.

This is a methodological study. A total of 143 Brazilian children with and without disabilities from ages 0 to 5 years and 11 months were included. Recruitment was voluntary, resulting from dissemination on social networks and partnerships with universities and teaching clinics in Brazil. The parents/guardians responded to the instrument YC-PEM. The variables analyzed were frequency of participation, involvement, and desire for change; supports, barriers, environmental helpfulness, environmental resources and overall environmental support, in the three sections: home, daycare/preschool and community, adopting a significance level of α=0.05. The Cronbach's alpha test was used to assess internal consistency (IC). To check the construct validity, we investigated differences between groups using Mann-Whitney or Chi-square tests.

73 children with (mean age 24.6 months) and 70 children without disabilities (mean age 30.9 months) of both genders participated, among which 41% attended daycare/preschool. Cronbach's alpha ranged from 0.625 to 0.991 in the different subscales, which confirms its internal consistency. As for construct validity, the instrument could detect statistically significant differences between the groups in the domains of frequency of participation and involvement in daycare/preschool, involvement in the community, help from the environment, resources and General support from the environment in all 3 instrument sections.

The YC-PEM Brazil has acceptable initial psychometric properties and is a valid option to evaluate the participation of young Brazilian children, with or without disabilities, in clinical practice and research.

The instrument can help health professionals to identify the levels of participation of children aged 0 to 5 years and plan interventions aspired at improving participation in different contexts. In addition, caregivers, who are active agents in the child's support process, can learn about participation and develop skills that promote greater management of their children's levels of functionality and autonomy.