Forty-three studies were included in the review (556 participants); seven before and after studies, one post-test only comparison study, 18 quasi-experimental studies and 17 multiple-baseline designs. Most studies included adequate protocol and participant descriptions, however adherence to intervention protocols, blinding and randomisation procedures were poorly reported. Most participants were recruited through convenience sampling.
Cognitive-communication impairment (26 studies):
Ten studies compared errorless learning with errorful/trial-and-error interventions in which error responses were not constrained. Three studies reported a statistically significant difference in recall performance/task performance; outcomes were generally positive in the remaining studies, but few studies reported effect size data. When errorless learning was compared to a modified intervention approach, another single approach (vanishing cues) or a mixed approach, outcomes were variable.
Nine studies assessed different variations of spaced-retrieval training with some positive findings, but few studies reported effect size data.
One study each assessed a Montessori-based intervention, an electronic memory aid, a problem solving strategy, a specific rehearsal strategy and mixed interventions with varying results; some of the studies had very small sample sizes.
Cognitive-communication activity limitations/participation restrictions (21 studies):
Eleven small studies assessed a verbal instruction strategy which found statistically significant improved performance compared to baseline.
Seven studies assessed spaced-retrieval training, either alone or in combination with other approaches; outcomes were generally positive.
Three studies assessed other interventions with varying results.