Validity of social-cognitive measures for physical activity in middle-school girls.

OBJECTIVE: The factorial validity and measurement equivalence/invariance of scales used to measure social-cognitive correlates of physical activity among adolescent girls were examined. METHODS: Confirmatory factor analysis was applied to questionnaire responses obtained from a multi-ethnic sample (N = 4885) of middle-school girls from six regions of the United States. A cohort of 1893 girls completed the scales in both sixth and eighth grades, allowing longitudinal analysis. RESULTS: Theoretically and statistically sound models were developed for each scale, supporting the factorial validity of the scales in all groups. Multi-group and longitudinal invariance was confirmed across race/ethnicity groups, age within grade, BMI categories, and the 2-year period between grades. CONCLUSIONS: The scores from the scales provide valid assessments of social-cognitive variables that are putative mediators or moderators of change in physical activity. The revised scales can be used in observational studies of change or interventions designed to increase physical activity among girls during early adolescence.

Girls' perception of physical environmental factors and transportation: reliability and association with physical activity and active transport to school.

BACKGROUND: Preliminary evidence suggests that the physical environment and transportation are associated with youth physical activity levels. Only a few studies have examined the association of physical environmental factors on walking and bicycling to school. Therefore, the purpose of this study was (1) to examine the test-retest reliability of a survey designed for youth to assess perceptions of physical environmental factors (e.g. safety, aesthetics, facilities near the home) and transportation, and (2) to describe the associations of these perceptions with both physical activity and active transport to school. METHODS: Test and retest surveys, administered a median of 12 days later, were conducted with 480 sixth- and eighth-grade girls in or near six U.S. communities. The instrument consisted of 24 questions on safety and aesthetics of the perceived environment and transportation and related facilities. Additionally, girls were asked if they were aware of 14 different recreational facilities offering structured and unstructured activities, and if so, whether they would visit these facilities and the ease with which they could access them. Test-retest reliability was determined using kappa coefficients, overall and separately by grade. Associations with physical activity and active transport to school were examined using mixed model logistic regression (n = 610), adjusting for grade, race/ethnicity, and site. RESULTS: Item-specific reliabilities for questions assessing perceived safety and aesthetics of the neighborhood ranged from 0.31 to 0.52. Reliabilities of items assessing awareness of and interest in going to the 14 recreational facilities ranged from 0.47 to 0.64. Reliabilities of items assessing transportation ranged from 0.34 to 0.58. Some items on girls' perceptions of perceived safety, aesthetics of the environment, facilities, and transportation were important correlates of physical activity and, in some cases, active transport to school. CONCLUSION: This study provides some psychometric support for the use of the questionnaire on physical environmental factors and transportation for studying physical activity and active transport to school among adolescent girls. Further work can continue to improve reliability of these self-report items and examine their association of these factors with objectively measured physical activity.

Physical activity attitudes, preferences, and practices in African American, Hispanic, and Caucasian girls.

Physical activity levels in girls decline dramatically during adolescence, most profoundly among minorities. To explore ethnic and racial variation in attitudes toward physical activity, semistructured interviews (n = 80) and physical activity checklists (n = 130) are conducted with African American, Hispanic, and Caucasian middle school girls in six locations across the United States. Girls from all groups have similar perceptions of the benefits of physical activity, with staying in shape as the most important. Girls have similar negative perceptions of physical activity, including getting hurt, sweating, aggressive players, and embarrassment. Chores, running or jogging, exercises, and dance are common activities for girls regardless of ethnicity. Basketball, swimming, running, and dance are commonly cited favorite activities, although there are slight differences between ethnic groups. The results suggest that factors other than ethnicity contribute to girls' physical activity preferences and that distinct interventions may not be needed for each ethnic group.

The significance of parks to physical activity and public health: a conceptual model.

Park-based physical activity is a promising means to satisfy current physical activity requirements. However, there is little research concerning what park environmental and policy characteristics might enhance physical activity levels. This study proposes a conceptual model to guide thinking and suggest hypotheses. This framework describes the relationships between park benefits, park use, and physical activity, and the antecedents/correlates of park use. In this classification scheme, the discussion focuses on park environmental characteristics that could be related to physical activity, including park features, condition, access, aesthetics, safety, and policies. Data for these categories should be collected within specific geographic areas in or around the park, including activity areas, supporting areas, the overall park, and the surrounding neighborhood. Future research should focus on how to operationalize specific measures and methodologies for collecting data, as well as measuring associations between individual physical activity levels and specific park characteristics. Collaboration among many disciplines is needed.

Self-management strategies mediate self-efficacy and physical activity.

BACKGROUND: Self-efficacy theory proposes that girls who have confidence in their capability to be physically active will perceive fewer barriers to physical activity or be less influenced by them, be more likely to pursue perceived benefits of being physically active, and be more likely to enjoy physical activity. Self-efficacy is theorized also to influence physical activity through self-management strategies (e.g., thoughts, goals, plans, and acts) that support physical activity, but this idea has not been empirically tested. METHODS: Confirmatory factor analysis was used to test the factorial validity of a measure of self-management strategies for physical activity. Next, the construct validity of the measure was tested by examining whether self-management strategies mediated the relationship between self-efficacy and self-reported physical activity, independently of several social-cognitive variables (i.e., perceived barriers, outcome expectancy value, and enjoyment), among cross-sectional samples of 6th grade (n=309) and 8th grade (n=296) girls tested between February 14 and March 17, 2002. Data were analyzed in 2004. RESULTS: Consistent with theory, self-efficacy had direct effects on the social-cognitive variables. The primary novel finding is that self-management strategies mediated the association of self-efficacy with physical activity in both samples. CONCLUSIONS: The measure of self-management strategies for physical activity yields valid scores among adolescent girls and warrants experimental study as a mediator of the influence of efficacy beliefs on physical activity.

The obesity epidemic: incidence and prevalence.

Obesity is a major public health problem in the United States and in Louisiana in particular. The prevalence of both overweight and obesity has increased in the past two decades. National studies and studies conducted in Louisiana in adults and children have shown that overweight and obesity are related to conditions such as hypertension, diabetes, stroke, and insulin resistance syndrome. Obesity tracks over time, with obese children and adolescents being more likely to become obese adults. Numerous intervention models to modify eating and exercise behaviors have been conducted with children in Louisiana and have shown that it is possible to reduce fat and saturated fat intakes and increase the amount of moderate to vigorous daily physical activity. More research is needed, however, in both health education programs and environmental influences if we are to be effective in making the necessary changes in eating and physical activity habits of children, adolescents, and adults to reduce the prevalence of obesity.

The condition of neighborhood parks following Hurricane Katrina: development of a Post-Hurricane Assessment instrument.

BACKGROUND: Parks provide environments for physical activity, yet little is known about how natural disasters affect them or how these disasters alter physical activity. Our objectives were to (1) describe the development of an instrument to assess park conditions following a hurricane and (2) document the conditions of New Orleans' parks 3 and 6 months after Hurricane Katrina. METHODS: A Post-Hurricane Assessment (PHA) instrument was developed and implemented in 54 parks 3 and 6 months post-hurricane. RESULTS: Summary scores of the Park Damage Index and the Neighborhood Damage Index showed improvement between 3 and 6 months of data collection. Parks and neighborhoods most affected by the hurricane were located in the most- and least-affluent areas of the city. CONCLUSION: The PHA proved to be a promising tool for assessing park conditions in a timely manner following a natural disaster and allowed for the creation of summary damage scores to correlate to community changes.

Commercial venues as supports for physical activity in adolescent girls.

OBJECTIVE: The purposes of this study were to describe the types and availability of commercial facilities for physical activity (PA) in six diverse geographic areas (Washington DC and Maryland; South Carolina; Minnesota; Louisiana; Arizona; and California) and to assess the relationship between those facilities and the non-school PA of adolescent girls. METHODS: A total of 1556 6th grade girls participating in the Trial of Activity for Adolescent Girls (TAAG) wore accelerometers for 7 days providing 6 days of complete data, completed questionnaires in 2003 and had their residential addresses geocoded. Nearby commercial facilities available to provide PA (i.e. dance studios, youth organizations) within a 1-mile radius of participants' residences were identified and geocoded. The association between the presence of any commercial PA facility and girls' PA was determined using a multi-level design and controlling for demographic characteristics and other potential confounders. Analyses were conducted in 2005-2006. RESULTS: Sixty-eight percent of the girls had at least one commercial PA facility near their homes. Availability and types of commercial PA facilities differed by where participants lived. Girls who lived near one or more commercial PA facilities had higher non-school MET-weighted moderate-to-vigorous PA than girls who had none near their homes. CONCLUSIONS: The findings suggest that commercial PA facilities are important contributors to the accumulation of PA among adolescent girls.

Development of a Direct Observation Instrument to Measure Environmental Characteristics of Parks for Physical Activity.

BACKGROUND: The study's purpose is to describe the development and evaluate the reliability (inter-observer agreement) and validity (rater agreement with a gold standard) of a direct observation instrument to assess park characteristics that may be related to physical activity. METHODS: A direct observation instrument of 181 items was developed based on a conceptual model consisting of the following domains: features, condition, access, esthetics, and safety. Fifteen pairs of observers were trained and sent to two parks simultaneously to assess two Target Areas each. RESULTS: Overall domain reliability was 86.9%, and overall geographic area reliability was 87.5%. Overall domain validity was 78.7% and overall geographic area validity was 81.5%. CONCLUSIONS: Inter-rater reliability and validity were generally good, although validity was slightly lower than reliability. Objective items showed the highest reliability and validity. Items that are time-sensitive may need to be measured on multiple occasions, while items asking for subjective responses may require more supervised practice.