Spaced retrieval as a tool to work with patients with Alzheimer’s disease

Introduction

Spaced retrieval (SR) is a non-pharmacological tool that enables patients with Alzheimer’s disease (AD) to learn new names, patterns of movements and whole sequences of activities. It bases the treatment on procedural memory rather than on semantic memory. It means that a person does not need to know the names of each procedure, or to know a fact, to be able to e.g. boil water. Spaced retrieval is a part of the error-less learning paradigm – it gives the correct answers to individuals, and its effectiveness is based on positive repetition and priming rather than questioning with a risk of a wrong answer being given and learned by the individual with memory impairment (Camp 1989; Lee et al. 2009).
A key component of SR training apart from executing the same question and answer is a time in between asking a question and demanding an answer. After a correct answer there is repetition of the training answer or training activity, with the time between questions growing exponentially – from the baseline of direct repetition to 10, 15, 30 seconds, 1, 2, 4 and so on minutes. If a wrong answer is provided by the participant, the trainer gives the correct/training response and then goes back to the last interval of time in which the correct answer was provided (Camp 1989).
Alzheimer’s disease is a neurodegenerative disease that primarily affects an individual’s cognitive functions. It not only impairs memory and language, but also interferes with learning (Small and Cochrane 2020). Therefore, it has a huge impact not only on the individual, but on the entire family or professional care systems (Park et al. 2015; Yıldızhan et al. 2019). Since the medical therapies implemented so far do not cure the disease, it is crucial to try to slow down the symptoms with non-pharmacological interactions, such as SR.
Since the previous review (Oren et al. 2014) was conducted almost a decade ago and the number of published studies has increased significantly, this review aims to expand our knowledge of the effectiveness of various SR implementations among AD patients.

Material and methods

Four databases (PubMed, EBSCO, Embase, Google Scholar) were searched systematically in August using the keywords: “Alzheimer’s disease OR dementia” AND “Spaced retrieval or SR”. The time frame was set from 2014 (previous review (Oren et al., 2014)) until 2023. The search was conducted according to PRISMA guidelines (Page et al., 2021).
Inclusion criteria are shown in Table 1.

Screening

The screening of the identified publications was completed by two independent researchers N.S. and G.P. and their decisions were blinded using the Rayyan tool. The detailed decision process can be found in Figure 1.
After checking all articles, 5 (≈10% of all checked articles) were included in this review.

Results

Two studies focused on Instrumental Activities of Daily Living (Bourgeois et al. 2016; Thivierge et al. 2014). One study used important events (e.g. birthdays) as a training material (Small and Cochrane 2020). One study used words formed from commonly used everyday words (Jang et al. 2015) and one focused on evaluating the effectiveness of the application (Zmily et al. 2014). The studies that proved to be effective were those in which the training took place at the participant’s current location (Bourgeois et al. 2016; Small and Cochrane 2020; Thivierge et al. 2014; Zmily et al. 2014).
Out of all participants, almost 58% were female. Training was provided by a specialist (psychologist, nurse, etc.). Effects of training involving IADL were proven to be successful even up to 3 months after training (Thivierge et al. 2014).
Effectiveness of the training was assessed purely on the ability to learn and/or use the trained material. Studies did not mention the pharmacotherapy administered to the participants.
Details of the studies included in this review may be found in Table 2.

Discussion

In this review, no significant differences were observed in overall cognitive functioning in patients with AD. However, improvement could be detected in learned daily living skills. The significant difference found in the results of IADL-based task performance after SR intervention indicates high ecological relevance of this method (Edgar et al. 2019), allowing its application to teaching a variety of complex activities of everyday life (such as using the telephone, preparing medications or managing money). In summary, the results of these studies underscore the multifaceted nature of IADL training and the needs and contexts of participants. Measuring IADL functioning is important because it is a clinically relevant outcome measure, affecting not only the patient, but also their support system, by increasing the financial and caregiver burden (Springate and Tremont 2014). Giving the gender, profession, and experience of the trainers, it is possible to develop more effective and sustainable IADL training programmes that significantly improve the quality of participant’s life. Perhaps most promisingly, the effects of the IADL training proved to be long-lasting, with improvements still evident up to three months after training. This underscores the potential for lasting benefits in increasing the ability of people with disease to perform daily tasks and ultimately lead more independent lives.

Conclusions

The current review concludes, compared to a previous meta-analysis (Oren et al. 2014), that SR training is more important for learning daily living skills than verbal semantic memory. This reinforces the recommendations for implementing SR in practice. What is even more crucial is the fact that the state of cognitive impairment was not a crucial factor for the effectiveness of the SR method. Both seniors with mild and those with moderate cognitive impairment were able to succeed in learning the tasks. Therefore this finding is especially crucial for specialists and families working with seniors with more severe cognitive impairment.
It seems very important to further study the effectiveness of the SR method in patients with AD. Such studies should include greater representativeness (especially in terms of gender). Studies involving a larger group of patients could also be particularly important. An interesting direction might be to compare the effectiveness of this type of intervention in home care and a nursing home.

Disclosures

The research for this publication has been supported by a grant from the Priority Research Area under the Strategic Programme Excellence Initiative at Jagiellonian University.
This study, as a literature review, is exempt from Institutional Review Board approval.
The authors declare no conflicts of interest.

References