Background: Although studies have shown that targeted interventions can improve cognitive abilities in older persons, it is unclear whether these gains translate into functional improvements as manifested by performance of instrumental activities of daily living (IADL). It also is unclear if interventions can prevent cognitive decline. A multicenter investigation called the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) study examined the long-term effects of three cognitive interventions on IADL.
The Study: Adults 65 years and older who lived independently and had good function and cognition were recruited for the study. Participants were randomized to one of three intervention groups (memory, reasoning, or speed-of-processing training) or a control group. Assessment was conducted by blinded assessors and took place at baseline, after the intervention, and at one, two, three, and five years. Training focused on specific skills such as mnemonic strategies, pattern finding, and visual search. Only 10 percent of the time was spent on applying these skills to practical situations (e.g., grocery shopping).
Participants attended 10 initial sessions, with booster sessions at 11 and 35 months offered to randomly selected persons who had completed the initial training. Outcome measures were cognitive abilities related to each of the three focused training interventions and IADL-related functional abilities as they pertained to improved cognitive function.
Results: The final sample included 2,802 participants, with 89 percent completing treatment. There was a 67 percent retention rate after five years. In general, patients continuing through the multiple stages of this study tended to be healthier and more educated than those who discontinued. All three cognitive training interventions, as well as the reasoning and speed-of-processing booster interventions, produced lasting improvements.
In addition, all intervention groups had better self-reported IADL functioning at five years compared with the control group, but the results were significant only in the reasoning training group. The intervention groups also had a less-steep decline in self-reported IADL. After controlling for baseline age and cognitive function, objective measures of IADL at five years showed significant improvement in speed-of-processing performance in the group that had received booster training (effect size 0.30; 99% confidence interval, 0.08 to 0.52).
Conclusion: The authors conclude that cognitive training interventions improve mental function and have long-lasting effects in healthy older persons. In addition, some beneficial effects on everyday functioning also may occur, but the results were modest and observed only at the end of the five years.