Browsing by Author "Norman, Gregory J"
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- ItemAn adaptive physical activity intervention for overweight adults: a randomized controlled trial.(2013-12-18) Adams, Marc A; Sallis, James F; Norman, Gregory J; Hovell, Melbourne F; Hekler, Eric B; Perata, ElyseBACKGROUND Physical activity PA interventions typically include components or doses that are static across participants Adaptive interventions are dynamic components or doses change in response to short term variations in participant s performance Emerging theory and technologies make adaptive goal setting and feedback interventions feasible OBJECTIVE To test an adaptive intervention for PA based on Operant and Behavior Economic principles and a percentile based algorithm The adaptive intervention was hypothesized to result in greater increases in steps per day than the static intervention METHODS Participants N 20 were randomized to one of two 6 month treatments 1 static intervention SI or 2 adaptive intervention AI Inactive overweight adults 85 women M 36 9 9 2 years 35 non white in both groups received a pedometer email and text message communication brief health information and biweekly motivational prompts The AI group received daily step goals that adjusted up and down based on the percentile rank algorithm and micro incentives for goal attainment This algorithm adjusted goals based on a moving window an approach that responded to each individual s performance and ensured goals were always challenging but within participants abilities The SI group received a static 10 000 steps day goal with incentives linked to uploading the pedometer s data RESULTS A random effects repeated measures model accounted for 180 repeated measures and autocorrelation After adjusting for covariates the treatment phase showed greater steps day relative to the baseline phase pUnder 001 and a group by study phase interaction was observed p 017 The SI group increased by 1 598 steps day on average between baseline and treatment while the AI group increased by 2 728 steps day on average between baseline and treatment a significant between group difference of 1 130 steps day Cohen s d 74 CONCLUSIONS The adaptive intervention outperformed the static intervention for increasing PA The adaptive goal and feedback algorithm is a behavior change technology that could be incorporated into mHealth technologies and scaled to reach large populations TRIAL REGISTRATION ClinicalTrials gov NCT01793064
- ItemClassification accuracies of physical activities using smartphone motion sensors.(2012-10-08) Wu, Wanmin; Dasgupta, Sanjoy; Ramirez, Ernesto E; Peterson, Carlyn; Norman, Gregory JBACKGROUND Over the past few years the world has witnessed an unprecedented growth in smartphone use With sensors such as accelerometers and gyroscopes on board smartphones have the potential to enhance our understanding of health behavior in particular physical activity or the lack thereof However reliable and valid activity measurement using only a smartphone in situ has not been realized OBJECTIVE To examine the validity of the iPod Touch Apple Inc and particularly to understand the value of using gyroscopes for classifying types of physical activity with the goal of creating a measurement and feedback system that easily integrates into individuals daily living METHODS We collected accelerometer and gyroscope data for 16 participants on 13 activities with an iPod Touch a device that has essentially the same sensors and computing platform as an iPhone The 13 activities were sitting walking jogging and going upstairs and downstairs at different paces We extracted time and frequency features including mean and variance of acceleration and gyroscope on each axis vector magnitude of acceleration and fast Fourier transform magnitude for each axis of acceleration Different classifiers were compared using the Waikato Environment for Knowledge Analysis WEKA toolkit including C4 5 J48 decision tree multilayer perception naive Bayes logistic k nearest neighbor kNN and meta algorithms such as boosting and bagging The 10 fold cross validation protocol was used RESULTS Overall the kNN classifier achieved the best accuracies 52 3 79 4 for up and down stair walking 91 7 for jogging 90 1 94 1 for walking on a level ground and 100 for sitting A 2 second sliding window size with a 1 second overlap worked the best Adding gyroscope measurements proved to be more beneficial than relying solely on accelerometer readings for all activities with improvement ranging from 3 1 to 13 4 CONCLUSIONS Common categories of physical activity and sedentary behavior walking jogging and sitting can be recognized with high accuracies using both the accelerometer and gyroscope onboard the iPod touch or iPhone This suggests the potential of developing just in time classification and feedback tools on smartphones
- ItemFeasibility and effectiveness of an automated bilingual text message intervention for weight loss: pilot study.(2013-11-08) Kolodziejczyk, Julia K; Norman, Gregory J; Barrera-Ng, Angelica; Dillon, Lindsay; Marshall, Simon; Arredondo, Elva; Rock, Cheryl L; Raab, Fred; Griswold, William G; Sullivan, Mark; Patrick, KevinBACKGROUND Little is known about the feasibility and acceptability of tailored text message based weight loss programs for English and Spanish language speakers OBJECTIVE This pilot study evaluated the feasibility acceptability and estimated impact of a tailored text message based weight loss program for English and Spanish language speakers The purpose of this pilot study was to inform the development of a full scale randomized trial METHODS There were 20 overweight or obese participants mean age 40 10 SD 8 05 8 20 40 male 9 20 45 Spanish speakers that were recruited in San Diego California from March to May 2011 and evaluated in a one group pre post clinical trial For 8 weeks participants received and responded to 3 5 text messages daily sent from a fully automated text messaging system They also received printed weight loss materials and brief 10 15 minute weekly counseling calls To estimate the impact of the program the primary outcome was weight kg measured during face to face measurement visits by trained research staff Pre and post differences in weight were analyzed with a one way repeated measures analysis of variance Differences by language preference at both time points were analyzed with t tests Body mass index and weight management behaviors also were examined Feasibility and acceptability were determined by recruitment success adherence ie percentage of replies to interactive text messages and attrition and participant satisfaction RESULTS Participants who completed the final assessment N 18 decreased body weight by 1 85 kg F1 17 10 80 P 004 CI 0 66 3 03 2 0 39 At both time points there were no differences in weight by language preference Participants responded to 88 04 986 1120 of interactive text messages attrition rate was 10 2 20 and 94 19 20 of participants reported satisfaction with the program CONCLUSIONS This fully automated text message based weight program was feasible with English and Spanish speakers and may have promoted modest weight loss over an 8 week period TRIAL REGISTRATION Clinicaltrials gov NCT01171586 http clinicaltrials gov ct2 show NCT01171586 Archived by WebCite at http www webcitation org 6Ksr6dl7n
- ItemFruit and vegetable intake and eating behaviors mediate the effect of a randomized text-message based weight loss program.(2013-01-08) Norman, Gregory J; Kolodziejczyk, Julia K; Adams, Marc A; Patrick, Kevin; Marshall, Simon JINTRODUCTION We hypothesized that fruit vegetable intake and eating behaviors mediate the relationship between experimental condition and weight loss in a randomized trial evaluating a text message based weight loss program METHODS Overweight obese individuals from San Diego CA N 52 with complete data were randomly assigned in 2007 into one of two groups for four months 1 the intervention group that received 2 5 weight management text messages p day 2 the usual care comparison group Three 24 hour recalls assessed fruit vegetable intake change and the eating behavior inventory EBI measured change in eating behaviors Regression path models tested intervention mediation RESULTS Direct effects of the intervention were found for change in body weight b 3 84 R 2 0 074 fruit vegetable intake b 2 00 R 2 0 083 and EBI scores b 7 15 R 2 0 229 ps Under 0 05 The treatment group to weight change path was not statistically significant b 0 673 R 2 0 208 when fruit vegetable intake change and EBI score change were specified as intervention mediators in the model The total indirect effect was 3 17 lb indicating that the indirect paths explained 82 6 of the total effect on weight change DISCUSSION Fruit vegetable intake and eating behaviors mediated the intervention s effect on weight change The findings suggest that sending text messages that promote healthy eating strategies resulted in moderate short term weight loss
- ItemOutcomes of a 12-month technology-based intervention to promote weight loss in adolescents at risk for type 2 diabetes.(2013-06-13) Patrick, Kevin; Norman, Gregory J; Davila, Evelyn P; Calfas, Karen J; Raab, Fred; Gottschalk, Michael; Sallis, James F; Godbole, Suni; Covin, Jennifer RBACKGROUND Obese adolescents are at risk for type 2 diabetes mellitus T2DM Obesity interventions delivered through media such as the web and text messages short message service SMS may be beneficial when targeting obese adolescents METHODS A randomized controlled trial Pace Internet for Diabetes Prevention Intervention PACEi DP compared three forms of an obesity intervention to usual care UC a website only W b website monthly group sessions and follow up calls WG and c website and SMS WSMS Participants were overweight or obese adolescents at risk for T2DM n 101 age 12 16 years mean body mass index BMI percentile 97 6 74 3 Hispanic In addition to the website WSMS participants received SMS supporting intervention goals and behavioral strategies and communicated via SMS with a case manager WG participants had additional group activities related to weight loss and received follow up calls from a health coach UC participants were given printed materials and encouraged to attend three initial group sessions Repeated measures mixed model regression analyses tested treatment effects for anthropometric behavioral and behavioral change strategy outcomes RESULTS There were no treatment effects for BMI adiposity physical activity or diet at 12 months Treatment effects were observed for sedentary behavior with the W arm having a greater decrease in sedentary behavior 4 9 to 2 8 h day than the UC arm p 006 CONCLUSION Although not sufficient to produce weight loss the combination of web intervention and group sessions with telephone follow up yielded improvements in sedentary behavior and in the use of behavior change strategies expected to lead to behavior change
- ItemPreparing adolescents with chronic disease for transition to adult care: a technology program.(2014-06-11) Huang, Jeannie S; Terrones, Laura; Tompane, Trevor; Dillon, Lindsay; Pian, Mark; Gottschalk, Michael; Norman, Gregory J; Bartholomew, L KayAdolescents with chronic disease ACD must develop independent disease self management and learn to communicate effectively with their health care team to transition from pediatric to adult oriented health care systems Disease specific interventions have been implemented to aid specific ACD groups through transition A generic approach might be effective and cost saving
- ItemA text message-based intervention for weight loss: randomized controlled trial.(2009-01-14) Patrick, Kevin; Raab, Fred; Adams, Marc A; Dillon, Lindsay; Zabinski, Marian; Rock, Cheryl L; Griswold, William G; Norman, Gregory JBACKGROUND To our knowledge no studies have evaluated whether weight loss can be promoted in overweight adults through the use of an intervention that is largely based on daily SMS Short Message Service text and MMS Multimedia Message Service small picture messages transmitted via mobile phones OBJECTIVE This paper describes the development and evaluation of a text message based intervention designed to help individuals lose or maintain weight over 4 months METHODS The study was a randomized controlled trial with participants being exposed to one of the following two conditions lasting 16 weeks 1 receipt of monthly printed materials about weight control 2 an intervention that included personalized SMS and MMS messages sent two to five times daily printed materials and brief monthly phone calls from a health counselor The primary outcome was weight at the end of the intervention A mixed model repeated measures analysis compared the effect of the intervention group to the comparison group on weight status over the 4 month intervention period Analysis of covariance ANCOVA models examined weight change between baseline and 4 months after adjusting for baseline weight sex and age RESULTS A total of 75 overweight men and women were randomized into one of the two groups and 65 signed the consent form completed the baseline questionnaire and were included in the analysis At the end of 4 months the intervention group n 33 lost more weight than the comparison group 1 97 kg difference 95 CI 0 34 to 3 60 kg P 02 after adjusting for sex and age Intervention participants adjusted average weight loss was 2 88 kg 3 16 At the end of the study 22 of 24 92 intervention participants stated that they would recommend the intervention for weight control to friends and family CONCLUSIONS Text messages might prove to be a productive channel of communication to promote behaviors that support weight loss in overweight adults