Background Smartphone apps are a promising tool for delivering accessible and appealing physical activity interventions. Given the large growth of research in this field, there are now enough studies using the “gold standard” of experimental design—the randomized controlled trial design—and employing objective measurements of physical activity, to support a meta-analysis of these scientifically rigorous studies. Objective This systematic review and meta-analysis aimed to determine the effectiveness of smartphone apps for increasing objectively measured physical activity in adults. Methods A total of 7 electronic databases (EMBASE, EmCare, MEDLINE, Scopus, Sport Discus, The Cochrane Library, and Web of Science) were searched from 2007 to January 2018. Following the Population, Intervention, Comparator, Outcome and Study Design format, studies were eligible if they were randomized controlled trials involving adults, used a smartphone app as the primary or sole component of the physical activity intervention, used a no- or minimal-intervention control condition, and measured objective physical activity either in the form of moderate-to-vigorous physical activity minutes or steps. Study quality was assessed using a 25-item tool based on the Consolidated Standards of Reporting Trials checklist. A meta-analysis of study effects was conducted using a random effects model approach. Sensitivity analyses were conducted to examine whether intervention effectiveness differed on the basis of intervention length, target behavior (physical activity alone vs physical activity in combination with other health behaviors), or target population (general adult population vs specific health populations). Results Following removal of duplicates, a total of 6170 studies were identified from the original database searches. Of these, 9 studies, involving a total of 1740 participants, met eligibility criteria. Of these, 6 studies could be included in a meta-analysis of the effects of physical activity apps on steps per day. In comparison with the control conditions, smartphone apps produced a nonsignificant ( P =.19) increase in participants’ average steps per day, with a mean difference of 476.75 steps per day (95% CI −229.57 to 1183.07) between groups. Sensitivity analyses suggested that physical activity programs with a duration of less than 3 months were more effective than apps evaluated across more than 3 months ( P =.01), and that physical activity apps that targeted physical activity in isolation were more effective than apps that targeted physical activity in combination with diet ( P =.04). Physical activity app effectiveness did not appear to differ on the basis of target population. Conclusions This meta-analysis provides modest evidence supporting the effectiveness of smartphone apps to increase physical activity. To...

It is well established that fundamental aspects of cognition such as memory and speed of processing tend to decline with age; however, there is substantial between-individual variability in levels of cognitive performance in older adulthood and in rates of change in cognitive abilities over time. Recent years have seen an increasing number of studies concerned with examining personality characteristics as possible predictors of some of this variability in cognitive aging. The purpose of this article is to review the literature, and identify patterns of findings regarding the relationships between personality (focusing on the Big-5) and cognitive ability across nonclinical populations of older adults. Possible mechanisms underlying associations of personality characteristics with cognition are reviewed, and assessed in the context of the current literature. Some relatively consistent relationships are identified, including positive associations between openness and cognitive ability, and associations of conscientiousness with slower rates of cognitive decline. However, the relationships between several personality traits and cognitive abilities in older adults remain unclear. We suggest some approaches to research design and analysis that may help increase our understanding of how personality differences may contribute to cognitive aging.

Background Poor diet and physical inactivity are leading modifiable causes of death and disease. Advances in artificial intelligence technology present tantalizing opportunities for creating virtual health coaches capable of providing personalized support at scale. Objective This proof of concept study aimed to test the feasibility (recruitment and retention) and preliminary efficacy of physical activity and Mediterranean-style dietary intervention (MedLiPal) delivered via artificially intelligent virtual health coach. Methods This 12-week single-arm pre-post study took place in Adelaide, Australia, from March to August 2019. Participants were inactive community-dwelling adults aged 45 to 75 years, recruited through news stories, social media posts, and flyers. The program included access to an artificially intelligent chatbot, Paola, who guided participants through a computer-based individualized introductory session, weekly check-ins, and goal setting, and was available 24/7 to answer questions. Participants used a Garmin Vivofit4 tracker to monitor daily steps, a website with educational materials and recipes, and a printed diet and activity log sheet. Primary outcomes included feasibility (based on recruitment and retention) and preliminary efficacy for changing physical activity and diet. Secondary outcomes were body composition (based on height, weight, and waist circumference) and blood pressure. Results Over 4 weeks, 99 potential participants registered expressions of interest, with 81 of those screened meeting eligibility criteria. Participants completed a mean of 109.8 (95% CI 1.9-217.7) more minutes of physical activity at week 12 compared with baseline. Mediterranean diet scores increased from a mean of 3.8 out of 14 at baseline, to 9.6 at 12 weeks (mean improvement 5.7 points, 95% CI 4.2-7.3). After 12 weeks, participants lost an average 1.3 kg (95% CI –0.1 to –2.5 kg) and 2.1 cm from their waist circumference (95% CI –3.5 to –0.7 cm). There were no significant changes in blood pressure. Feasibility was excellent in terms of recruitment, retention (90% at 12 weeks), and safety (no adverse events). Conclusions An artificially intelligent virtual assistant-led lifestyle-modification intervention was feasible and achieved measurable improvements in physical activity, diet, and body composition at 12 weeks. Future research examining artificially intelligent interventions at scale, and for other health purposes, is warranted.

BackgroundThe success of a mobile phone app in changing health behavior is thought to be contingent on engagement, commonly operationalized as frequency of use.ObjectiveThis subgroup analysis of the 2 intervention arms from a 3-group randomized controlled trial aimed to examine user engagement with a 100-day physical activity intervention delivered via an app. Rates of engagement, associations between user characteristics and engagement, and whether engagement was related to intervention efficacy were examined.MethodsEngagement was captured in a real-time log of interactions by users randomized to either a gamified (n=141) or nongamified version of the same app (n=160). Physical activity was assessed via accelerometry and self-report at baseline and 3-month follow-up. Survival analysis was used to assess time to nonuse attrition. Mixed models examined associations between user characteristics and engagement (total app use). Characteristics of super users (top quartile of users) and regular users (lowest 3 quartiles) were compared using t tests and a chi-square analysis. Linear mixed models were used to assess whether being a super user was related to change in physical activity over time.ResultsEngagement was high. Attrition (30 days of nonuse) occurred in 32% and 39% of the gamified and basic groups, respectively, with no significant between-group differences in time to attrition (P=.17). Users with a body mass index (BMI) in the healthy range had higher total app use (mean 230.5, 95% CI 190.6-270.5; F2=8.67; P<.001), compared with users whose BMI was overweight or obese (mean 170.6, 95% CI 139.5-201.6; mean 132.9, 95% CI 104.8-161.0). Older users had higher total app use (mean 200.4, 95% CI 171.9-228.9; F1=6.385; P=.01) than younger users (mean 155.6, 95% CI 128.5-182.6). Super users were 4.6 years older (t297=3.6; P<.001) and less likely to have a BMI in the obese range (χ22=15.1; P<.001). At the 3-month follow-up, super users were completing 28.2 (95% CI 9.4-46.9) more minutes of objectively measured physical activity than regular users (F1,272=4.76; P=.03).ConclusionsTotal app use was high across the 100-day intervention period, and the inclusion of gamified features enhanced engagement. Participants who engaged the most saw significantly greater increases to their objectively measured physical activity over time, supporting the theory that intervention exposure is linked to efficacy. Further research is needed to determine whether these findings are replicated in other app-based interventions, including those experimentally evaluating engagement and those conducted in real-world settings.Trial RegistrationAustralian New Zealand Clinical Trials Registry ACTRN12617000113358; https://www.anzctr.org.au/ACTRN12617000113358.aspx

Having a sense of purpose is recognized as an important resource for maintaining health and well-being over the life span. We examined associations of individual differences in sense of purpose with levels and rates of change in indices of aging well (health, cognition, and depressive symptoms) in a sample of 1,475 older adults (Mage = 77.06 years, SD = 6.27; 50% female) assessed on up to 6 occasions over 18 years. We also conducted survival analysis to examine associations of purpose with longevity. We hypothesized that a higher sense of purpose would be associated with better performance on the aging well measures, and that those with a higher sense of purpose would show shallower declines in aging well over time. Results indicated that participants who scored higher on sense of purpose reported lower levels of functional disability, performed better on cognitive tests (episodic memory and speed of processing), and reported better self-rated health and fewer depressive symptoms. Sense of purpose was not associated with individual differences in rates of change in the aging well indices with the exception of speed of processing, for which a higher sense of purpose was associated with marginally shallower rates of decline. Higher sense of purpose was also associated with increased probability of survival, although this association became weaker over time. The findings support the notion that purposeful living contributes to health and well-being. At the same time, higher sense of purpose may not buffer against more pervasive losses in health that become more common in oldest-old adulthood.