The International Classification of Functioning, Disability and Health (ICF) core sets for deafblindness, part II of the systematic review: linking data to the ICF categories.

Introduction: Deafblindness, a health condition with varying combinations of hearing and vision impairment, affects functioning and social participation. In 2001, the World Health Organization (WHO) introduced the International Classification of Functioning, Disability, and Health (ICF) to examine human health and functioning. To use the ICF in clinical practice, smaller categories of ICF codes, referred to as Core Sets, were developed for specific health conditions. However, no ICF Core Set exists for deafblindness. As part of an ICF Core Set development, this paper examines the existing literature from an ICF perspective and links relevant data to the ICF categories.

Evidence acquisition: The systematic review followed the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA). Articles were selected from eight scientific databases, three journals, and Google Scholar. The research team linked outcome measures and qualitative studies to ICF codes using ICF linking rules. For each measure/qualitative study's final code list, they included each code only once after eliminating any duplicates. Subsequently, a frequency analysis was conducted, and ICF categories identified in at least five studies were included in the candidate categories list.

Evidence synthesis: 147 articles met the eligibility criteria. Most studies were from Europe (N.=70) and North America (N.=41). 316 categories were identified in at least five studies that belong to one of four ICF components. This includes 112 categories in the body function component, 3 categories in body structure, 163 in activities and participation, and 38 in environmental factors. Additionally, 21 personal factors relating to demographics were identified. The most frequent category was listening (category d115) at 82.31%, followed by range of emotions (category b1522) at 78.91%, hearing function (category b230) at 68.03%, and assistive products and technology for communication (category e1251) at 63.27%.

Conclusions: As the second part of the first four studies in developing ICF Core Sets for deafblindness, this review described the ICF categories relevant to the functioning of individuals with deafblindness. These categories inform the development of the Core Sets on deafblindness from the researcher's perspective. The final Core Sets will guide clinical practice, programs, and policies for individuals with deafblindness.