Table 2.
Study characteristics of included systematic reviews
| Reference | Aim | Search strategy | Included studies (N) | Study design | Total number of participants | Population | Outcomes | Risk of bias |
| Di Marco et al 40 | To provide a comprehensive summary of modifiable lifestyle factors (dietary habits, leisure activities, social network and so on) associated with the risk of late-onset incident dementia. | NR to 2013. PubMed, Ovid MEDLINE, PsycINFO, In-Process & Other Non-Indexed Citations. Search terms provided English-language publications. |
6 (cognitive leisure activities). | Longitudinal observational cohort studies. | NR | ≥65 years, adults without dementia at baseline. | No quantitative analysis. Cognitive leisure activities might be associated with reduced incidence of all-cause dementia. |
High |
| Opdebeeck et al 41 | To assess the relationship between cognitive reserve (educational level, occupational status and engagement in cognitively stimulating activities) and cognition in multiple domains. | NR to 2014. PubMed, PsycINFO, ScienceDirect, CINAHL. Search terms provided. |
31 (cognitively stimulating activities). | 31 cross- sectional studies. | 24 561 | ≥60 years (at least 80% of study participants). | SMD: 0.26 (95% CI 0.21 to 0.32). Participating in cognitive leisure activities is associated with improved cognitive functions (including memory, working memory, executive function, visuospatial ability and language). |
High |
| Sajeev et al 42 | To assess if engaging in late-life cognitive activities is able to delay or prevent dementia. | NR to June 2014. PubMed and EMBASE. No search terms provided. |
12 (cognitively stimulating activities). | 10 prospective cohort studies; 2 nested case–control studies. |
13 939 (dementia: 1663; AD: 565) |
≥45 years. | No quantitative analysis. Late-life cognitive activity might be associated with lower AD and/or all-cause dementia incidence. |
Medium |
| Toril et al 43 | To investigate the extent to which cognitive training with video games enhances cognitive functions in healthy older adults. | 1986–2013. MEDLINE, PsycINFO and Google Scholar. Search terms provided English-language publications. |
20 (video game training). | 18 controlled studies; 2 uncontrolled studies. | 913 (474 trained, 439 healthy controls) | 50–86 years, healthy older adults. | SMD: 0.37 (95% CI 0.26 to 0.48). Video game training is associated with improved cognitive functions in older adults (including memory, attention, reaction time, cognitive function and executive functions). |
High |
| Yates et al 44 | To assess the impact of cognitively stimulating leisure activities on cognition and risk of dementia in later life. | 2004–2014. PsycINFO, MEDLINE, CINAHL, EMBASE and the Web of Science. Search terms provided. |
19 (cognitive leisure activities). | 17 cohort studies; 2 case–control studies. | 32 546 | ≥46 years, cognitively healthy adults (ie, no diagnosis of impairment or dementia). |
All-cause dementia incidence:
RR: 0.61 (95% CI 0.42 to 0.90), k=3, RE. HR: 0.58 (95% CI 0.46 to 0.74), k=2, RE. OR: 0.78 (95% CI 0.67 to 0.90), k=2, FE. Cognitive impairment incidence: OR: 0.69 (95% CI 0.56 to 0.85), k=5, RE. HR: 0.85 (95% CI 0.71 to 1.02), k=3, RE, NS. |
Medium |
AD, Alzheimer’s-type dementia; CINAHL, Cumulative Index to Nursing and Allied Health Literature; FE, fixed effects model; k, studies that assessed cognitive activities only; NR, not reported; NS, not significant; RE, random effects model; RR, risk ratio; SMD, standardised mean difference.