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Biomedical subjects

Gregory J Norman

Publications and source records attributed to Gregory J Norman.

18 recordsLinked to original sources
PubMed2007

Patterns of sedentary behavior among adolescents.

OBJECTIVE: Reducing certain sedentary behaviors (e.g., watching television, using a computer) can be an effective weight loss strategy for youth. Knowledge about whether behaviors cluster together could inform interventions. STUDY DESIGN: Estimates of time spent in 6 sedentary behaviors (watching television, talking on the telephone, using a computer, listening to music, doing homework, reading) were cluster analyzed for a sample of 878 adolescents (52% girls, mean age = 12.7 years, 58% Caucasian). MAIN OUTCOME MEASURES: The clusters were based on the sedentary behaviors listed above and compared on environmental variables (e.g., household rules), psychosocial variables (e.g., self-efficacy, enjoyment), and health behaviors (e.g., physical activity, diet). RESULTS: Four clusters emerged: low sedentary, medium sedentary, selective high sedentary, and high sedentary. Analyses revealed significant cluster differences for gender (p < .002), age (p < .002), body mass index (p < .001), physical activity (p < .01), and fiber intake (p < .01). CONCLUSIONS: Results suggest a limited number of distinct sedentary behavior patterns. Further study is needed to determine how interventions may use cluster membership to target segments of the adolescent population.

Adolescent↗
PubMed2006

Patterns and correlates of physical activity and nutrition behaviors in adolescents.

BACKGROUND: Knowledge of the prevalence, clustering, and correlates of multiple adolescent health behaviors can inform the design of health promotion interventions. METHODS: A cross-sectional design was used to assess 878 adolescents aged 11 to 15 years (53.6% girls, 58% non-Hispanic white) recruited in primary care clinics in 2001-2002. Adolescent physical activity (assessed with accelerometers), television viewing time (reported), percent calories from fat, and servings of fruits and vegetables (assessed with multiple 24-hour recalls) were dichotomized into meeting or not meeting national guidelines. Parent health behaviors were assessed with self-reported measures. Analyses were conducted in 2006. RESULTS: Fifty-five percent of adolescents did not meet the physical activity guideline, and 30% exceeded 2 hours daily of television viewing time, with boys more active and less sedentary than girls (p <0.01). The majority of the adolescents did not meet dietary guidelines. Nearly 80% had multiple risk behaviors and only 2% met all four guidelines. The number of risk behaviors was associated with being older and being at risk for overweight or being overweight, for boys and girls (p <0.05). Two parent health behaviors-history of smoking and failure to meet the fruits and vegetables guideline-were significantly associated with a higher number of risk behaviors for girls (p <0.05). CONCLUSIONS: Eight of ten adolescents in this sample failed to meet guidelines for two or more diet, physical activity, and sedentary risk behaviors. Some parent health behaviors, along with the adolescent's weight status and age, were associated with a higher number of adolescent health risk behaviors.

Adolescent↗
PubMed2006

Randomized controlled trial of a primary care and home-based intervention for physical activity and nutrition behaviors: PACE+ for adolescents.

OBJECTIVE: Many adolescents do not meet national guidelines for participation in regular moderate or vigorous physical activity (PA); limitations on sedentary behaviors; or dietary intake of fruits and vegetables, fiber, or total dietary fat. This study evaluated a health care-based intervention to improve these behaviors. DESIGN: Randomized controlled trial. SETTING: Primary care with follow-up at home. PARTICIPANTS: Eight hundred seventy-eight adolescent girls and boys aged 11 to 15 years. INTERVENTIONS: Two experimental conditions: (1) Primary care, office-based, computer-assisted diet and PA assessment and stage-based goal setting followed by brief health care provider counseling and 12 months of monthly mail and telephone counseling and (2) a comparison condition addressing sun exposure protection. MAIN OUTCOME MEASURES: Minutes per week of moderate plus vigorous PA measured by self-report and accelerometer; self-report of days per week of PA and sedentary behaviors; and percentage of energy from fat and servings per day of fruits and vegetables measured by three 24-hour diet recalls. Body mass index (calculated as weight in kilograms divided by the square of height in meters) was a secondary outcome. RESULTS: Compared with adolescents in the sun protection condition, girls and boys in the diet and PA intervention significantly reduced sedentary behaviors (intervention vs control change, 4.3 to 3.4 h/d vs 4.2 to 4.4 h/d for girls, respectively [P = .001]; 4.2 to 3.2 h/d vs 4.2 to 4.3 h/d for boys, respectively [P = .001]). Boys reported more active days per week (intervention vs control change: 4.1 to 4.4 d/wk vs 3.8 to 3.8 d/w, respectively [P = .01]), and the number of servings of fruits and vegetables for girls approached significance (intervention vs control change, 3.5 to 4.2 servings/d vs 3.5 to 3.9 servings/d, respectively [P = .07]). No intervention effects were seen with percentage of calories from fat or minutes of PA per week. Percentage of adolescents meeting recommended health guidelines was significantly improved for girls for consumption of saturated fat (intervention vs control change, 23.4% to 41.0% vs 18.5% to 31%, respectively [relative risk, 1.33; 95% confidence interval, 1.01-1.68]) and for boys' participation in d/wk of PA (intervention vs control change, 45.3% to 55.4% vs 41.9% to 38.0%, respectively [relative risk, 1.47; 95% confidence interval, 1.19-1.75]). No between-group differences were seen in body mass index. CONCLUSIONS: Improvements in some diet, PA, and sedentary behaviors in adolescents can be enabled through the use of a 1-year, integrated intervention using the computer, health provider counseling, mail, and telephone. The amount of intervention received may contribute to its efficacy.

Adolescent↗
PubMed2006

Psychosocial correlates of fruit, vegetable, and dietary fat intake among adolescent boys and girls.

OBJECTIVE: This study examined whether hypothesized psychosocial correlates of behavior change (family/peer influence, pros, cons, self-efficacy, parent/child change strategies, and household eating rules) are associated with consumption of fruits, vegetables, and dietary fat among adolescent boys and girls. DESIGN: This cross-sectional study used questionnaires to assess psychosocial variables and multiple 24-hour recall interviews to assess dietary intake (daily servings of fruits and vegetables and percentage energy intake from dietary fat). SUBJECTS: In this study, 878 adolescents (53.6% female, 57.9% white, mean age 12.8 years, age range 11 to 15 years) completed questionnaires. STATISTICAL ANALYSES PERFORMED: Hierarchical linear regressions were conducted on the entire sample as well as on subgroups based on sex and age (young/old). RESULTS: Results indicated that child behavior change strategies, decisional balance, and household rules were related to percentage energy intake from total fat, whereas child behavior change strategies, family influence, and household rules were related to daily servings of fruit and vegetables. More psychosocial correlates were found for older than for younger adolescents. CONCLUSIONS: Both psychological and social correlates of adolescent eating behaviors were identified, and correlates differed somewhat by adolescent subgroup. Based on these findings, promising intervention strategies that include the following should be evaluated: helping adolescents alter decisional balance, teaching behavior-change strategies, and helping parents support children's dietary changes and institute supportive household rules.

Adolescent↗
PubMed2006

A randomized trial of a brief mental health intervention for primary care patients.

This randomized trial is a first evaluation of a brief psychotherapeutic intervention for primary care patients. Sixty-two participants were randomly assigned to the intervention or to treatment as usual. As compared with treatment as usual, the intervention led to significant reductions in symptoms of anxiety and depression. The reduction was maintained for 3 months after the end of treatment, but some return of symptoms occurred by 6 months after treatment. The treatment was well accepted by patients. This study provides good preliminary evidence for the effectiveness of this intervention.

Adult↗
PubMed2006

Construct validity of physical activity and sedentary behaviors staging measures for adolescents.

PURPOSE: To evaluate the construct validity of physical activity (PA) and sedentary behaviors (SB) staging measures for adolescents that incorporate the current national recommendations. METHOD: The Progressive Aerobic Cardiovascular Endurance Run, Actigraph accelerometer, and self-reported hours of TV viewing served as criterion measures. Participants were 878 adolescents (M age = 12.74, 53.6% girls, 39.9% non-White). RESULTS: The PA staging measure had mixed evidence of convergent validity and strong evidence of divergent validity. The SB staging measure had strong and generalized evidence of convergent validity but weak evidence of divergent validity, which could be related to inaccurate assumptions about the relation of SB to PA and fitness. Results were generally in the expected direction and provide preliminary evidence for the construct validity and generalizability of both staging measures. However, more research is warranted to validate the staging measures with Actigraph-measured PA and sedentary time. Effect sizes (eta(2) values) ranged from small to large (.02-.63). CONCLUSION: PA and SB stage-of-change measures that are congruent with current national recommendations and appropriate for use among adolescents were partially supported for their construct validity.

Adolescent↗
PubMed2005

Identifying high- and low-success smoking cessation subgroups using signal detection analysis.

Signal detection analysis was used to identify mutually exclusive groups of smokers (n = 602) at high and low likelihood for smoking cessation 6- and 18-months post-entry into a smoking cessation intervention. Overall quit rates were 10% at 6-months and 18% at 18-months. Four subgroups were identified at 6-months and five at 18-months. The highest quit-rate subgroup at both time points (42% and 52% cessation, respectively) had low perceived stress. The lowest quit-rate subgroup (7% and 13% cessation, respectively) had higher perceived stress, lower self-efficacy to not smoke, lower use of behavioral processes at 6-months, and higher use of pros of smoking at 18-months. These smoker profiles may be useful in developing targeted smoking cessation interventions. Addressing perceived stress in smoking cessation interventions may help to improve smoking cessation success rates.

Adolescent↗
PubMed2005

Comparability and reliability of paper- and computer-based measures of psychosocial constructs for adolescent fruit and vegetable and dietary fat intake.

BACKGROUND: This study investigated the comparability and reliability of computer- and paper-based measures of psychosocial constructs related to fruit and vegetable and dietary fat intake among adolescents. METHODS: An ethnically diverse sample of 76 adolescents was studied (mean age 13 years). Scales measured use of change strategies, self-efficacy, decisional balance, family influences, and peer influences separately for the two dietary outcomes. RESULTS: Comparability analyses indicated that responses for each of the 12 diet-related scales were not significantly different between the computer- and paper-based surveys. Internal consistencies were generally high (alpha from .61 to .97) with slightly better reliability on the computer- vs paper-based surveys. Test-retest reliabilities were adequate to good for most multiple-item scales (interclass correlation coefficients from .43 to .85 and .48 to .90 for paper and computer formats, respectively). CONCLUSIONS: Computer- and paper-based measures of psychosocial constructs are appropriate and ready for use in either format for studies of dietary behaviors in young people.

Adolescent↗
PubMed2005

Comparability and reliability of paper- and computer-based measures of psychosocial constructs for adolescent physical activity and sedentary behaviors.

This study assessed the comparability and reliability of paper-based and computer-based administration of psychosocial construct measures related to adolescents engaging in physical activity and sedentary behaviors. Adolescents (n = 76; 55% girls, 49% Hispanic, 18% non-Hispanic-white; M age = 13 years) completed measures of behavior change strategies, self-efficacy, decisional balance, family and peer influences, enjoyment, activity choices, and environmental influences. Overall, the adolescents provided equivalent responses on paper and computer formats. Reliability estimates were generally good for the multiple-item constructs, but single-item measures tended to demonstrate low reliability. Average scale internal consistency was significantly higher for measures administered with the computer format compared to the paper format, but test-rest reliability estimates were not significantly different between formats.

Adolescent↗
PubMed2005

Psychosocial and environmental correlates of adolescent sedentary behaviors.

OBJECTIVE: To determine correlates of sedentary behaviors in adolescents through the examination of psychosocial and environmental variables. METHOD: The study used a cross-sectional design to evaluate an ethnically diverse clinic-based sample of 878 adolescents who were 11 to 15 years old. Bivariate and multivariate analyses were stratified by gender to assess correlates of sedentary behaviors occurring on the most recent nonschool day (television viewing, computer video games, sitting listening to music, and talking on the phone). RESULTS: For girls, age, family support, television/video rules, and hills in the neighborhood were associated with sedentary behaviors. Furthermore, psychological constructs such as self-efficacy, enjoyment, change strategies, and pros and cons of change emerged as correlates of sedentary behaviors. A moderator effect revealed that the proportion of girls in the low-BMI group decreased with increased self-efficacy, whereas the proportion of girls in the high-BMI group did not vary significantly by self-efficacy. For boys, age, ethnicity, BMI, cons of change, and self-efficacy were associated with sedentary behaviors. CONCLUSIONS: This study provides evidence of factors associated and not associated with adolescent sedentary behaviors. Similar to physical activity, measures of specific psychosocial constructs of sedentary behavior demonstrated important associations. The results highlight the need for additional examination of the correlates of sedentary behavior to determine which correlates are mechanisms of behavior change.

Adolescent↗
PubMed2004

A framework for modeling health behavior protocols and their linkage to behavioral theory.

With the rise in chronic, behavior-related disease, computerized behavioral protocols (CBPs) that help individuals improve behaviors have the potential to play an increasing role in the future health of society. To be effective and widely used CBPs should be based on accepted behavioral theory. However, designing CBPs while at the same time specifying their linkages to behavioral theory and developing reusable CBP components (interventions) are challenges to developers of CBPs. Having an ontology with which to describe CBPs could help with these issues. As a first step towards creating such an ontology, we modeled PACE-Adolescent, a theory-based behavioral protocol that uses the Stages of Change Model and Social Cognitive Theory, using PROTEGE-2000, an ontology editor and knowledge acquisition system. We created a three-part knowledge model. Two sub-ontologies described behavioral interventions and psychological theories. The third component, implemented using Guideline Interchange Format (GLIF3), provided a way to describe the structure of a protocol and to link intervention resources and groups of actions to elements of psychological theory. Using this framework, we formally described the PACE-Adolescent protocol. Creating knowledge models such as this may lead to improvements in the design and evaluation of computerized health behavior protocols.

Adolescent↗
PubMed2004

Diet, physical activity, and sedentary behaviors as risk factors for overweight in adolescence.

BACKGROUND: The proportion of overweight adolescents has increased, but the behavioral risk factors for overweight youth are not well understood. OBJECTIVE: To examine how diet, physical activity, and sedentary behaviors relate to overweight status in adolescents. DESIGN AND SETTING: Baseline data from the Patient-Centered Assessment and Counseling for Exercise Plus Nutrition Project, a randomized controlled trial of adolescents to determine the effects of a clinic-based intervention on physical activity and dietary behaviors. PARTICIPANTS: A total of 878 adolescents aged 11 to 15 years, 42% of whom were from minority backgrounds. MAIN OUTCOME MEASURE: Centers for Disease Control and Prevention body mass index-for-age percentiles divided into 2 categories: normal weight (<85th percentile) and at risk for overweight plus overweight (AR + O) (>or=85th percentile). RESULTS: Overall, 45.7% of the sample was classified as AR + O with a body mass index for age at the 85th percentile or higher. More girls from minority backgrounds (54.8%) were AR + O compared with non-Hispanic white girls (42%) (chi(2)(1) = 7.6; P =.006). Bivariate analyses indicated that girls and boys in the AR + O group did fewer minutes per day of vigorous physical activity, consumed fewer total kilojoules per day, and had fewer total grams of fiber per day than those in the normal-weight group. Boys in the AR + O group also did fewer minutes per day of moderate physical activity and watched more minutes per day of television on nonschool days than normal-weight boys. Final multivariate models indicated that independent of socioeconomic status (as assessed by household education level), girls had a greater risk of being AR + O if they were Hispanic or from another minority background (odds ratio [OR] = 1.65; 95% confidence interval [CI], 1.09-2.49) and a reduced risk of being AR + O as minutes per day of vigorous physical activity increased (OR = 0.93; 95% CI, 0.89-0.97). A low level of vigorous physical activity was the only significant risk factor for boys being AR + O (OR = 0.92; 95% CI, 0.89-0.95). Analyses based on meeting behavioral guidelines supported these findings and showed that failing to meet the 60 min/d moderate to vigorous physical activity guideline was associated with overweight status for both girls and boys. In addition, boys who failed to meet sedentary behavior and dietary fiber guidelines were more likely to be overweight. CONCLUSIONS: Of the 7 dietary and physical activity variables examined in this cross-sectional study, insufficient vigorous physical activity was the only risk factor for higher body mass index for adolescent boys and girls. Prospective studies are needed to clarify the relative importance of dietary and physical activity behaviors on overweight in adolescence.

Adolescent↗
PubMed2003

Developing an empirical typology for regular exercise.

BACKGROUND: Tailored interventions require the identification of distinct homogenous subgroups that will benefit from different intervention materials. One way to identify such subgroups is to use cluster analysis to identify an empirical typology. METHODS: A sample of 346 adults completed surveys through a telephone interview that included questions related to participating in regular exercise. The three variables used in the cluster analysis were the Pros of Exercise, the Cons of Exercise, and Exercise Self-Efficacy. RESULTS: Six resulting clusters were labeled Disengaged, Immotive, Relapse Risk, Early Action, Maintainers, and Habituated. A series of analyses tested the internal and external validity of the typology. The internal validity test revealed that four of the clusters demonstrated high stability and replicability, while the Relapse Risk and Early Action clusters were less stable. Differences among clusters on self-reported exercise behavior and a strong association with stage of change for regular exercise provided external validity evidence of the typology. CONCLUSIONS: The resulting typology reflects a range of motivational patterns that are likely to be responsive to different types of messages and strategies regarding adoption and maintenance of regular exercise. The typology also generates a number of hypotheses about the identified clusters that can be empirically tested in further studies.

Adult↗
PubMed2002

Independent evaluation of the California Tobacco Control Program: relationships between program exposure and outcomes, 1996-1998.

OBJECTIVES: This study sought to determine the effects of the California Tobacco Control Program on tobacco-related attitudes and behaviors. METHODS: In 1996 and 1998, a telephone survey was conducted among adults in randomly selected households in 18 California counties. Tenth-grade youths in 84 randomly selected high schools completed a written survey. In analyses conducted at the county level, differences in outcomes were regressed on an index of program exposure. RESULTS: Among adults, program exposure was associated with decreased smoking prevalence rates, increased no-smoking policies in homes, and decreased violations of workplace no-smoking policies. Among youths, there was no effect of program exposure on outcomes. CONCLUSIONS: These results suggest that the California Tobacco Control Program may have reduced adult smoking prevalence rates and exposure to environmental tobacco smoke.

Adolescent↗
PubMedDate not supplied

A practice-sponsored Web site to help patients pursue healthy behaviors: an ACORN study.

PURPOSE: We tested whether patients are more likely to pursue healthy behaviors (eg, physical activity, smoking cessation) if referred to a tailored Web site that provides valuable information for behavior change. METHODS: In a 9-month pre-post comparison with nonrandomized control practices, 6 family practices (4 intervention, 2 control) encouraged adults with unhealthy behaviors to visit the Web site. For patients from intervention practices, the Web site offered tailored health advice, a library of national and local resources, and printouts for clinicians. For patients from control practices, the Web site offered static information pages. Patient surveys assessed stage of change and health behaviors at baseline and follow-up (at 1 and 4 months), Web site use, and satisfaction. RESULTS: During the 9 months, 932 patients (4% of adults attending the practice) visited the Web site, and 273 completed the questionnaires. More than 50% wanted physician assistance with health behaviors. Stage of change advanced and health behaviors improved in both intervention and control groups. Intervention patients reported greater net improvements at 1 month, although the differences approached significance only for physical activity and readiness to change dietary fat intake. Patients expressed satisfaction with the Web site but wished it provided more detailed information and greater interactivity with clinicians. CONCLUSIONS: Clinicians face growing pressure to offer patients good information on health promotion and other health care topics. Referring patients to a well-designed Web site that offers access to the world's best information is an appealing alternative to offering handouts or impromptu advice. Interactive Web sites can facilitate behavior change and can interface with electronic health records. Determining whether referral to an informative Web site improves health outcomes is a methodological challenge, but the larger question is whether information alone is sufficient to promote behavior change. Web sites are more likely to be effective as part of a suite of tools that incorporate personal assistance.

Adult↗
PubMedDate not supplied

Construct validity of the stages of change of exercise adoption for different intensities of physical activity in four samples of differing age groups.

PURPOSE: To examine whether the stages of change of exercise adoption appropriately address strenuous, moderate, and mild intensities of physical activity. DESIGN AND SETTING: Secondary analysis of four data sets investigating transtheoretical model (TTM) constructs for exercise adoption. SUBJECTS: Four samples of differing age groups (adolescents, n = 400; college students, n = 240; adults, n = 346; seniors, n = 504). MEASURES: Stage of change algorithm for exercise adoption and self-reported physical activity. RESULTS: Multivariate analysis of variance (MANOVA) results showed that stages of change were distinguished by strenuous and moderate but not mild exercise in the adolescent, college student, and adult sample. In the senior sample, stage differences were found in the frequency of exercising (equivalent for moderate to strenuous exercise) and the frequency of walking (equivalent for mild exercise). Bivariate correlation coefficients as well as sensitivity, specificity, and related quality indices decreased respectively from strenuous to moderate to mild exercise and from exercising to walking. CONCLUSIONS: Results provide additional support for the construct validity of the stages of change for strenuous and moderate intensities of physical activity. Development of a new stage assessment instrument for mild intensities of physical activity is recommended. Limitations include use of a different validation measure of exercise behavior in the senior sample.

Adolescent↗
PubMedDate not supplied

Psychosocial correlates of dietary intake among overweight and obese men.

OBJECTIVES: To investigate the relationship between theoretically based psychosocial constructs and dietary components among overweight men. METHODS: Participants were 441 men (BMI M = 34.2). Psychosocial constructs included self-efficacy, decisional balance, social support, and behavior change strategies. Dietary components were fat, fiber, and fruit and vegetable intake. RESULTS: All significant findings were in the expected direction. Multiple regression models indicated that the psychosocial factors accounted for the most variance in vegetable intake (R(2)=.13) and the least variance in fat (R(2)=.05). CONCLUSIONS: Theoretically based psychosocial constructs were related to overweight men's dietary intake and have potential for use in tailored behavior-change interventions.

Adult↗