Objective. To investigate what evidence is available from systematic reviews on the effects of assistive products (AP) for communication and information for people with communication disabilities.
Materials and methods. Reviews were identified from an overview of systematic reviews. By means of defined keywords 12 databases were searched from 2000 to April 2010 with no language restrictions. Systematic reviews on outcomes research on AP for communication and information were included, except alarms and hearing or visions aids. Descriptive and outcomes data were extracted, internal and external validity were assessed by means of "Assessment of Multiple Systematic Reviews" (AMSTAR), and the quality of evidence of the findings was presented according to the GRADE system (Grading of Recommendations, Assessment, Development and Evaluation).
Results. Five reviews were identified. Three reviews had only minor and one moderate methodological limitations, while in one review the limitations were major. The overall quality of evidence was low or unclear, because of methodological limitations of the original studies. Based on one review of moderate quality AP seems to have certain beneficial effects for students with literacy problems. Four reviews on effectiveness of alternative and augmentative communication products conclude that there may be beneficial effects of the AP for people with developmental disabilities in their daily and vocational activities, but that the quality of evidence is low.
Conclusion. Potential benefits of AP for communication and information were found and summarized by population and device type. New methods for grading studies with small populations are warranted. Development of feasible and valid outcome measures and well-designed outcomes studies on communication and information devices to inform clinical decision-making are urgently needed.