Definitions of deafblindness and congenital deafblindness.
Half of deafblind studies skip the definition—spell out sensory levels every time you assess or publish.
01Research in Context
What this study did
Flemming and colleagues read every research paper they could find on congenital deafblindness. They asked a simple question: do the authors actually say what they mean by deafblind?
They pulled 149 studies. Only 45% gave any definition at all. Even fewer—just 25%—explained what congenital deafblind means.
What they found
The review shows a mess. Without clear labels, one study’s deafblind group could be another study’s hard-of-hearing plus low-vision group. Comparing results is almost impossible.
In short, half the field is writing recipes that forget to list the ingredients.
How this fits with other research
Dammeyer (2011) counted mental-health diagnoses in 95 congenitally deafblind adults. Flemming’s team would flag that paper as helpful—it actually says how deafblindness was decided.
Dammeyer (2014) used the Autism Behavior Checklist in deafblind kids. Flemming would note the study never defines the sensory loss, so high autism scores might be sensory artifacts, not autism.
Moss et al. (2009) tripled detection of deafblindness in adults with ID once they ran hearing and vision screens. Flemming’s point: if you don’t screen and define, you miss people—and you can’t compare studies.
Wright et al. (2022) later fixed the problem. They published a deaf-adapted ADI-R with clear sensory criteria. That move answers Flemming’s 2014 call: give exact definitions and validated tools.
Why it matters
Before you write a report or start a new client file, write one sentence that says how you decided the person is deafblind. List hearing level, vision level, and onset age. Copy that sentence into every assessment, behavior plan, and graph. Your data will finally talk to the next BCBA’s data.
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02At a glance
03Original abstract
In order to compile knowledge on deafblindness (DB) and congenital deafblindness (CDB), one important factor is comparison of results between different scientific studies. In an attempt to do a systematic review of the literature on cognitive assessment and CDB, considerable difficulties in determining eligibility of the studies were encountered due to heterogeneity in definitions and inclusion criteria used in the articles. The present systematic review aims to provide both an overview of this terminological and methodological heterogeneity and suggestions for better future research practices. A systematic review of definitions used in (N=30) studies employing psychological assessment of people with CDB served as a sample of the scientific literature on DB and CDB. Absent or heterogeneous definitions and inclusion criteria regarding both DB and CDB are evident in the sample. Fifty percent of the studies reported no definition of DB and 76.7% reported no definition of CDB. Main discrepancies are: (1) medical/functional versus ability/functioning definitions regarding DB; and (2) different criteria for onset of DB in the case of defining CDB (e.g. age versus developmental level). The results of this study call attention to a scientifically inadequate approach to the study of DB and CDB. Findings indicate that clear guidelines for sample descriptions of the DB and/or CDB populations are needed. It is suggested that studies including DB and CDB participants provide the following information: definitions of DB and CDB used; severity of sensory impairments; level of sensory ability in relation to mobility, access to information, and communication; age at onset of DB; and communication as well as language ability at onset of DB.
Research in developmental disabilities, 2014 · doi:10.1016/j.ridd.2014.05.029