The associations between proxy measures of cognitive reserve (CR) and cognition vary across studies and cognitive domains. This meta-analysis aimed to assess the relationship between CR and cognition in multiple domains (memory, executive function, visuospatial ability, and language). CR was considered in terms of three key proxy measures-educational level, occupational status, and engagement in cognitively-stimulating activities-individually and in combination. One-hundred and thirty-five studies representing 128,328 participants were included. Of these, 109 used a measure of education, 19 used a measure of occupation, 31 used a measure of participation in cognitively-stimulating activities, and six used a combination of these. All three proxy measures had a modest positive association with cognition; occupational status and cognitive activities showed the most variation across cognitive domains. This supports the view that the commonly-used proxy measures of CR share an underlying process but that each additionally provides a unique contribution to CR.

Background Core outcome sets (COS) prioritise outcomes based on their importance to key stakeholders, reduce reporting bias and increase comparability across studies. The first phase of a COS study is to form a ‘long-list’ of outcomes. Key stakeholders then decide on their importance. COS reporting is described as suboptimal and this first phase is often under-reported. Our objective was to develop a ‘long-list’ of outcome items for non-pharmacological interventions for people with dementia living at home. Methods Three iterative phases were conducted. First, people living with dementia, care partners, health and social care professionals, policymakers and researchers ( n = 55) took part in interviews or focus groups and were asked which outcomes were important. Second, existing dementia trials were identified from the ALOIS database. 248 of 1009 pharmacological studies met the inclusion criteria. Primary and secondary outcomes were extracted from a 50% random sample ( n = 124) along with eight key reviews/qualitative papers and 38 policy documents. Third, extracted outcome items were translated onto an existing qualitative framework and mapped into domains. The research team removed areas of duplication and refined the ‘long-list’ in eight workshops. Results One hundred seventy outcome items were extracted from the qualitative data and literature. The 170 outcome items were consolidated to 54 in four domains (Self-Managing Dementia Symptoms, Quality of Life, Friendly Neighbourhood & Home, Independence). Conclusions This paper presents a transparent blueprint for ‘long-list’ development. Though a useful resource in their own right, the 54 outcome items will be distilled further in a modified Delphi survey and consensus meeting to identify core outcomes.

BackgroundThe key aim of the study is to establish an agreed standardised core outcome set (COS) for use when evaluating non-pharmacological health and social care interventions for people living at home with dementia.Methods/designDrawing on the guidance and approaches of the Core Outcome Measures in Effectiveness Trials (COMET), this study uses a four-phase mixed-methods design:Focus groups and interviews with key stakeholder groups (people living with dementia, care partners, relevant health and social care professionals, researchers and policymakers) and a review of the literature will be undertaken to build a long list of outcomes.Two rounds of Delphi surveys will be used with key stakeholder groups. Statements for the Delphi surveys and participation processes will be developed and informed through substantial member involvement with people living with dementia and care partners. A consensus meeting will be convened with key participant groups to discuss the key findings and finalise the COS.A systematic literature review will be undertaken to assess the properties of tools and instruments to assess components of the COS. Measurement properties, validity and reliability will be assessed using the Consensus-based Standards for the Selection of Health Measurement (COSMIN) and COMET guidance.A stated preference survey will elicit the preferences of key stakeholders for the outcomes identified as important to measure in the COS.DiscussionTo the best of our knowledge, this study is the first to use a modified Delphi process to involve people living with dementia as a participant group. Though the study is confined to collecting data in the United Kingdom, use of the COS by researchers will enhance the comparability of studies evaluating non-pharmacological and community-based interventions.Trial registrationThe study is registered on the COMET initiative, registered in 2014 at comet-initiative.org.Electronic supplementary materialThe online version of this article (10.1186/s13063-018-2584-9) contains supplementary material, which is available to authorized users.

These results demonstrate that CR, indexed by a composite score based on multiple indicators, can moderate the negative association between lowered mood and cognition, emphasising the importance of continuing to build CR across the lifespan in order to maintain cognitive health.