Pouladi 2016.

Methods	Parallel‐group randomised controlled trial
Participants	Inclusion criteria: understood Persian; age > 18 years; having an artificial airway for ≥ 18 hours; ability to understand and work orders, i.e. people with GCS score 11; no audio imperfections. Exclusion criteria: reluctance to participate.
Interventions	Intervention Received a communication board including numbers, letters, words, and images used for 12 hours. Nurses show the communication board every 4 hours. Control Usual care comprising non‐verbal communication way, such as lip‐reading, pen and paper.
Outcomes	Satisfaction.
Notes	Trial registration states study is complete but unable to locate published study and no response from study contact.

CAM‐ICU: Confusion Assessment Method – ICU; GCS: Glasgow Coma Score; ICU: intensive care unit; RASS: Richmond Agitation Sedation Scale; SVCCM: Society of Critical Care Medicine.