Ethics approval was granted from the National Committee on Research Ethics for Health in El Salvador (CNEIS/2018/043) and the Institutional Review Board at the University of Pittsburgh (number PRO18010578). Written informed consent was obtained from all participants before implementing study procedures.
All procedures of the study were conducted at 11 different rehabilitation centers, that served as wheelchair service delivery centers, in El Salvador.
A consecutive sampling method was used to select participants using the waitlists at the 11 rehabilitation centers. The investigators recruited wheelchair users and their caregivers.
Following the initial assessment, all participants were placed on a waiting list until wheelchairs and services were available. All study participants were provided with a new wheelchair (standard, active, or all-terrain model), a wheelchair cushion, and wheelchair services, delivered by trained wheelchair service providers, according to the WHO 8-step wheelchair service delivery process including assessment, fitting, and a 30-minute individual or group training on 7 wheelchair skills, device care, and pressure injury prevention techniques.
In addition, all wheelchairs were provided with a basic contour cushion made of polyurethane foam. However, whenever a risk of pressure injury was identified for a study participant, wheelchair providers fabricated a pressure-relief cushion based on the WHO basic wheelchair service guidelines.
Data were collected between January and November 2019, by a group of eight data collectors from the University of El Salvador.
Study participants were interviewed during the wheelchair assessment (about 2 months before wheelchair delivery), at the wheelchair delivery visit, and at 3- and 6-month follow-up visits after wheelchair delivery. Participants who were not able to attend a follow-up visit were interviewed by phone. Data were collected using the following questionnaires and tools translated into Spanish which included demographic, clinical and wheelchair-related questions, wheelchair skills, maintenance patterns, poverty probability, quality of life, and all their health related questions. Data loggers (DLs) were also used to assess number of days of wheelchair use, daily distance traveled, and speed. Caregivers were interviewed to measure caregiver burden at baseline, at 3-month follow-up, and at 6-month follow-up.