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Gregory J Norman

Publications and source records attributed to Gregory J Norman.

11 recordsLinked to original sources

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↗

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↗

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↗

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↗

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↗

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↗

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↗

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↗

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↗

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↗