Screening of Cognitive Changes in Adults with Intellectual Disabilities: A Systematic Review

Round 1

Reviewer 1 Report

This is a well presented and insightful article highlighting the utility of the Screening and assessment of cognitive changes in adults with Intellectual Disabilities. The analysis and findings are thorough and robustly undertaken. Strengths and limitations are clearly presented.

I would only like to point out that another recent article published on 3 July 2020 and which has partly different objectives (Krinsky-McHale et al., Promising outcome measures of early Alzheimer's dementia in adults with Down syndrome DOI: 10.1002/dad2.12044) also reports that DLD is included in the measures that "provide essential tools to inform current clinical diagnosis" especially for people with suspected dementia

Author Response

Dear reviewer, we do appreciate your appraisal of our work! We included the new article in our review. By the way, thanks for pointing this.

Reviewer 2 Report

The organization of the manuscript remains difficult to follow. If this is a review of measures, the manuscript should be organized as such, as opposed to being organized by longitudinal vs. cross-sectional study in which they were used.

Author Response

Dear reviewer, 

We do appreciate the time you spent reviewing our article. We have made important improvements on the manuscript based on your valuable suggestions: i) we counted the number of informant-based and self-report-based studies (see page 6 and markers on tables). The reader can now easily find the two modalities of instruments as you suggested. ii) We add footnotes to the tables in Appendix B instead of supplemental material it facilitates the identification of acronyms. We also carefully considered your suggestion of dividing the paper by modalities of instruments. There are three major reasons to use the current structure. First, this is beneficial to the readers who are interested in instruments as repeated measures,  which is crucial for clinical assessment and follow up studies. Second, studies were separated by clinical groups (DS-ID and other ID; only DS) allowing the reader to consider if the measures used would overlap among different aetiological groups since these groups present different manifestations of dementia. Third, at the moment there is neither recommendation to use proxy and self-report measures in isolation nor indication that one modality is more effective than the other (except severe ID). Rather guidelines recommend the combination of measures and interdisciplinary assessment. Finally, changing the structure would demand to reformulate the entire manuscript, including all tables, without changing the conclusions reached. Considering these arguments in assembly, we kept the distinction concerning clinical groups and study design because it provides more insights for the neuropsychologists.

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

It seems to me an interesting and well-constructed study with rigorous criteria, I also appreciated because it helps to guide researchers, but also health service providers to use standardized tools, which we have an evident replicability even in multicultural contexts and above all with highlighted psychometric properties .
The comparison criteria and the search of the databases seem to me well explained and clear as well as the exclusion criteria.
I do not detect particular criticalities and the references seem to me up to date with the current research.

Reviewer 2 Report

Topic to include DS and all with ID is too broad to be clinically useful. 

Reviewer 3 Report

• The organization of the paper is difficult to follow. I am not sure that there is a need to separate measures out by whether the study reviewed was longitudinal or cross-sectional, when in fact the same measure is often used in both types of studies. If anything, it makes more sense to separate measures by informant- vs. self-report.
• It would make more sense to organize the discussion by measure as opposed to discussing the same measure in more than one section. The organization by study methodology and whether the study included people with DS vs. people with other ID is difficult to follow.
• There needs to be a deeper discussion of the implications of this review. What does this add to the literature?
• The focus of your study is on the use of a measure, yet your tables do not describe the validity of the dementia screener or cognitive test, but rather describe broader study outcomes. For example, in your table, for study 48 the outcomes is: 56% of participants preferred facial
  pictograms scales over drawn face
  stimuli. How is this relevant to your overarching study purpose/discussion of tools to assess dementia in this population?