228 research outputs found

    Recruitment of young adults for weight gain prevention: randomized comparison of direct mail strategies

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    Abstract Background Recruiting young adults (ages 18–35 years) into weight gain prevention intervention studies is challenging and men are particularly difficult to reach. This paper describes two studies designed to improve recruitment for a randomized trial of weight gain prevention interventions. Study 1 used a quasi-experimental design to test the effect of two types of direct mailings on their overall reach. Study 2 used a randomized design to test the effect of using targeted messages to increase recruitment of men into the trial. Methods For Study 1, 60,000 male and female young-adult households were randomly assigned to receive either a recruitment brochure or postcard. Visits to recruitment websites during each mailing period were used to assess response to each mailing. Study 2 focused on postcard recruitment only. These households received either a targeted or generic recruitment postcard, where targeted postcards included the word “Men” in the headline text. Response rates to each type of card were categorized based on participant report of mailing received. Results The reach of the postcards and brochures were similar (421 and 386 website visits, respectively; P = 0.22). Individuals who received the brochure were more likely to initiate the online screener than those who received a postcard (P = 0.01). In Study 2, of those who completed the telephone screening, 60.9 % of men (n = 23) had received the targeted postcard as compared to the generic postcard (39.1 %, P = 0.30). The reverse was true for women (n = 62, 38.7 vs. 61.3 %, P = 0.08). Conclusions These studies suggest there was little difference in the reach of postcards versus brochures. However, recipients of brochures were more likely to continue to the next stage of study participation. As expected, men’s response to the weight gain prevention messages was lower than women’s response; but using targeted messages appears to have modestly increased the proportion of male respondents. These studies add to the limited experimental literature on recruitment messaging and provide further indication for using targeted messages to reach underrepresented populations while providing initial evidence on the effect of mailing type on message reach. Trial registration The Study of Novel Approaches to Weight Gain Prevention was registered with ClinicalTrials.gov (identifier: NCT01183689) on 13 August 2010

    High Dimensional Classification of Structural MRI Alzheimer’s Disease Data Based on Large Scale Regularization

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    In this work we use a large scale regularization approach based on penalized logistic regression to automatically classify structural MRI images (sMRI) according to cognitive status. Its performance is illustrated using sMRI data from the Alzheimer Disease Neuroimaging Initiative (ADNI) clinical database. We downloaded sMRI data from 98 subjects (49 cognitive normal and 49 patients) matched by age and sex from the ADNI website. Images were segmented and normalized using SPM8 and ANTS software packages. Classification was performed using GLMNET library implementation of penalized logistic regression based on coordinate-wise descent optimization techniques. To avoid optimistic estimates classification accuracy, sensitivity, and specificity were determined based on a combination of three-way split of the data with nested 10-fold cross-validations. One of the main features of this approach is that classification is performed based on large scale regularization. The methodology presented here was highly accurate, sensitive, and specific when automatically classifying sMRI images of cognitive normal subjects and Alzheimer disease (AD) patients. Higher levels of accuracy, sensitivity, and specificity were achieved for gray matter (GM) volume maps (85.7, 82.9, and 90%, respectively) compared to white matter volume maps (81.1, 80.6, and 82.5%, respectively). We found that GM and white matter tissues carry useful information for discriminating patients from cognitive normal subjects using sMRI brain data. Although we have demonstrated the efficacy of this voxel-wise classification method in discriminating cognitive normal subjects from AD patients, in principle it could be applied to any clinical population

    Using Network Science to Evaluate Exercise-Associated Brain Changes in Older Adults

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    Literature has shown that exercise is beneficial for cognitive function in older adults and that aerobic fitness is associated with increased hippocampal tissue and blood volumes. The current study used novel network science methods to shed light on the neurophysiological implications of exercise-induced changes in the hippocampus of older adults. Participants represented a volunteer subgroup of older adults that were part of either the exercise training (ET) or healthy aging educational control (HAC) treatment arms from the Seniors Health and Activity Research Program Pilot (SHARP-P) trial. Following the 4-month interventions, MRI measures of resting brain blood flow and connectivity were performed. The ET group's hippocampal cerebral blood flow (CBF) exhibited statistically significant increases compared to the HAC group. Novel whole-brain network connectivity analyses showed greater connectivity in the hippocampi of the ET participants compared to HAC. Furthermore, the hippocampus was consistently shown to be within the same network neighborhood (module) as the anterior cingulate cortex only within the ET group. Thus, within the ET group, the hippocampus and anterior cingulate were highly interconnected and localized to the same network neighborhood. This project shows the power of network science to investigate potential mechanisms for exercise-induced benefits to the brain in older adults. We show a link between neurological network features and CBF, and it is possible that this alteration of functional brain networks may lead to the known improvement in cognitive function among older adults following exercise

    A Voxel-Based Morphometry Study Reveals Local Brain Structural Alterations Associated with Ambient Fine Particles in Older Women

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    Objective: Exposure to ambient fine particulate matter (PM2.5: PM with aerodynamic diameters < 2.5 μm) has been linked with cognitive deficits in older adults. Using fine-grained voxel-wise analyses, we examined whether PM2.5 exposure also affects brain structure

    Air Pollution and the Dynamic Association Between Depressive Symptoms and Memory in Oldest-Old Women

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    BACKGROUND/OBJECTIVES Exposure to air pollution may contribute to both increasing depressive symptoms and decreasing episodic memory in older adulthood, but few studies have examined this hypothesis in a longitudinal context. Accordingly, we examined the association between air pollution and changes in depressive symptoms (DS) and episodic memory (EM) and their interrelationship in oldest-old (aged 80 and older) women. DESIGN Prospective cohort data from the Women\u27s Health Initiative Memory Study-Epidemiology of Cognitive Health Outcomes. SETTING Geographically diverse community-dwelling population. PARTICIPANTS A total of 1,583 dementia-free women aged 80 and older. MEASUREMENTS Women completed up to six annual memory assessments (latent composite of East Boston Memory Test and Telephone Interview for Cognitive Status) and the 15-item Geriatric Depression Scale (GDS-15). We estimated 3-year average exposures to regional particulate matter with aerodynamic diameter below 2.5 μm (PM2.5) (interquartile range [IQR] = 3.35 μg/m3) and gaseous nitrogen dioxide (NO2) (IQR = 9.55 ppb) at baseline and during a remote period 10 years earlier, using regionalized national universal kriging. RESULTS Latent change structural equation models examined whether residing in areas with higher pollutant levels was associated with annual changes in standardized EM and DS while adjusting for potential confounders. Remote NO2 (β = .287 per IQR; P = .002) and PM2.5 (β = .170 per IQR; P = .019) exposure was significantly associated with larger increases in standardized DS, although the magnitude of the difference, less than 1 point on the GDS-15, is of questionable clinical significance. Higher DS were associated with accelerated EM declines (β = −.372; P = .001), with a significant indirect effect of remote NO2 and PM2.5 exposure on EM declines mediated by DS. There were no other significant indirect exposure effects. CONCLUSION These findings in oldest-old women point to potential adverse effects of late-life exposure to air pollution on subsequent interplay between DS and EM, highlighting air pollution as an environmental health risk factor for older women

    Outdoor Air Pollution Exposure and Inter-relation of Global Cognitive Performance and Emotional Distress in Older Women

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    The interrelationships among long-term ambient air pollution exposure, emotional distress and cognitive decline in older adulthood remain unclear. Long-term exposure may impact cognitive performance and subsequently impact emotional health. Conversely, exposure may initially be associated with emotional distress followed by declines in cognitive performance. Here we tested the inter-relationship between global cognitive ability, emotional distress, and exposure to PM2.5 (particulate matter with aerodynamic diameter 2 (nitrogen dioxide) in 6118 older women (aged 70.6 ± 3.8 years) from the Women’s Health Initiative Memory Study. Annual exposure to PM2.5 (interquartile range [IQR] = 3.37 μg/m3) and NO2 (IQR = 9.00 ppb) was estimated at the participant’s residence using regionalized national universal kriging models and averaged over the 3-year period before the baseline assessment. Using structural equation mediation models, a latent factor capturing emotional distress was constructed using item-level data from the 6-item Center for Epidemiological Studies Depression Scale and the Short Form Health Survey Emotional Well-Being scale at baseline and one-year follow-up. Trajectories of global cognitive performance, assessed by the Modified-Mini Mental State Examination (3MS) annually up to 12 years, were estimated. All effects reported were adjusted for important confounders. Increases in PM2.5 (β = -0.144 per IQR; 95% CI = −0.261; −0.028) and NO2 (β = −0.157 per IQR; 95% CI = −0.291; −0.022) were associated with lower initial 3MS performance. Lower 3MS performance was associated with increased emotional distress (β = −0.008; 95% CI = −0.015; −0.002) over the subsequent year. Significant indirect effect of both exposures on increases in emotional distress mediated by exposure effects on worse global cognitive performance were present. No statistically significant indirect associations were found between exposures and 3MS trajectories putatively mediated by baseline emotional distress. Our study findings support cognitive aging processes as a mediator of the association between PM2.5 and NO2 exposure and emotional distress in later-life

    Objectively-assessed physical activity and weight change in young adults: a randomized controlled trial

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    Abstract Background Reductions in physical activity (PA) are common throughout young adulthood and low PA is associated with weight gain. The SNAP Trial previously reported that two self-regulation approaches to weight gain prevention reduced weight gain over a 2-year period in 18–35 year olds. Presented here are secondary analyses examining changes in PA and the relationship between PA and weight change over 2 years. Methods 599 young adults (age: 27.4 ± 4.4 yrs.; BMI: 25.4 ± 2.6 kg/m2) were randomly assigned to 1 of 3 treatment arms: Small Changes (reduce calorie intake by 100 kcals/day & add 2000 steps/day), Large Changes (lose 2.3–4.5 kg initially & increase PA to ≥250 min/wk), or Self-guided (control condition). Small and Large Changes received 10, face-to-face group sessions (months 1–4), and two 4-week refresher courses each subsequent year. Body weight and PA were objectively-measured at baseline, 4 months, 1 and 2 years. Daily steps and bout-related moderate-to-vigorous intensity PA (MVPA: ≥3 METs, ≥10-min bouts) was calculated. Results Changes in bout-related MVPA and daily steps did not differ among treatment groups over the 2-year period (p’s > 0.16). Collapsed across groups, participants gaining >1 lb. (n = 187; 39.6%) had smaller changes in bout-related MVPA at 4 months, 1 and 2 years relative to those maintaining or losing weight (≤1 lb. weight gain; n = 282, 60.4%, p’s 1 lb. did not differ on daily steps (p’s > 0.10). Among participants engaging in ≥250 min/wk. of MVPA at 2 years (n = 181), 30% gained >1 lb. from baseline to 2 years, which was not different from those engaging in 150–250 min/wk. (n = 87; 36%; p = 0.40), but this percentage was significantly lower when compared to those engaging in 150 min/week of MVPA is needed for weight gain prevention and that increasing MVPA, rather than steps, should be targeted. Trial registration www.clinicaltrials.gov (NCT01183689). Registered Aug 13, 2010

    Recruitment of young adults into a randomized controlled trial of weight gain prevention: message development, methods, and cost

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    Abstract Background Young adulthood (age 18 to 35) is a high-risk period for unhealthy weight gain. Few studies have recruited for prevention of weight gain, particularly in young adults. This paper describes the recruitment protocol used in the Study of Novel Approaches to Prevention (SNAP). Methods We conducted extensive formative work to inform recruitment methods and message development. We worked with a professional marketing firm to synthesize major themes and subsequently develop age-appropriate messages for recruitment. A variety of approaches and channels were used across two clinical centers to recruit young adults who were normal or overweight (body mass index (BMI) 21 to 30 kg/m2) for a 3-year intervention designed to prevent weight gain. We tracked recruitment methods, yields, and costs by method. Logistic regression was used to identify recruitment methods that had the highest relative yield for subgroups of interest with covariate adjustments for clinic. Results The final sample of 599 participants (27% minority, 22% male) was recruited over a 19-month period of sustained efforts. About 10% of those who initially expressed interest via a screening website were randomized. The most common reason for ineligibility was already being obese (BMI >30 kg/m2). The top two methods for recruitment were mass mailing followed by email; together they were cited by 62% of those recruited. Television, radio, paid print advertising, flyers and community events each yielded fewer than 10% of study participants. Email was the most cost-effective method per study participant recruited. Conclusions These findings can guide future efforts to recruit young adults and for trials targeting weight gain prevention. Trial registration ClinicalTrials.gov NCT01183689 (registered 13 August 2010)
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