The study was conducted according to current French legislation (loi Jardé (n°2012-300).It was a cross-sectional study with a convergent parallel mixed method design. It used an online open survey following the STROBE and CHERRIES guidelines. A tailored survey with closed and open questions was used to obtain complementarity data on the topic i.e. to identify the most frequent life situations for children with disabilities for which a product or technology could be useful and drill deeper in these situations with responders' personal experiences to characterize those situations and identify wished solutions.

Survey's development The survey was developed by a group involving three Physical Medicine and Rehabilitation physicians and two occupational therapists. The conceptual framework of the ICF (International Classification of Functioning, Disability and health) which recognizes the role of environmental factors in the creation of disability was used. The survey was pilot tested by two mothers of children with disabilities and an adult who has had a disability since childhood. Comments were considered to improve the survey in a second version.

It was developed using an online tool (google form). Three versions were developed targeting the three participant profiles: persons with childhood onset disabilities, their relatives and the professionals who work with them. Each version was composed of 14 to 16 questions (in 6 pages). Firstly, participants had access to a description of the study with a dedicated picture so that making everyone aware of the project, and precising the general objective of the study. Then, questions were asked on epidemiological data. In a second step, a closed multiple-choice question was presented with a pre-established list of life situations of a regular day. Responders had to select the life situations which they evaluated as the most difficult for children with disabilities to be involved in. Respondents could tick as many items as they wished. All items were extracted from validated scales ("Life H": assesment of Life habits/ "ABILHAND assessment" / "ABILOCO KIDS"/ "PEDI": Paediatric Evaluation of Disability Inventory / "ACTIVLIM-CP"). The list was proposed in a chronological order in order to help the responder think of his own life. Then, open questions invited the respondents to precise the ticked items. The first open question proposed to precisely describe examples from the respondents' own experience (hereinafter referred to as "difficulties") in regular weekdays. Then they had to describe wished strategies that could allow an improvement (hereinafter referred to as "solutions"). Eventually, these last three questions were repeated but dealing with weekend and holidays situations instead of regular weekday situations. The survey was conceived to be short and take less than 10 minutes. Respondents could review and change their answers. No completeness check was proposed. Responders could not be identified from the survey (no identity data, no email or Internet Protocol (IP) address), thus anonymity was guaranteed.

Survey's distribution Participants were surveyed through convenience and snowball sampling to obtain data from participants with a wide range of situations between March and December 2019. The survey was promoted in France through "SFERHE" (Société Francophone d'Etudes et de Recherche sur les Handicaps de l'Enfance) and through the "EACD" (European Academy of Childhood Disability). A leaflet was prepared to present the project. It was posted in hospitals and distributed on social media (Linked in, Facebook, Twitter), and by e-mail. To facilitate the diffusion, the survey was addressed to families and patients' organisations (FFAIMC, "Fondation PC", "AFM"), professional networks ("réseaux maladies rares") and directly promoted during professional events (e.g. "EACD 2019 Paris", "SOFMER 2019 Bordeaux"). Participants answered voluntarily, no incentive was proposed.