Correlation of habitual physical activity levels with flow mediated dilation of the brachial artery in 5-10 year old children

Endothelial dysfunction is an early key event of atherogenesis. Both fitness level and exercise intervention have been shown to positively influence endothelial function. In a cross-sectional study of 47 children, the relationship between habitual physical activity and flow-mediated dilation (FMD) of the brachial artery was explored. Habitual physical activity levels (PALs) were assessed using a validated stable isotope technique, and FMD of the brachial artery was measured via high-resolution ultrasound. The results showed that habitual physical activity significantly correlated with FMD (r=0.39, P=0.007), and remained the most influential variable on dilation in multivariate analysis. Although both fitness level and exercise intervention have previously been shown to positively influence FMD, this is the first time that a relationship with normal PALs has been investigated, especially, at such a young age. These data support the concept that physical activity exerts its protective effect on cardiovascular health via the endothelium and add further emphasis to the importance of physical activity in childhood.

Social-cognitive and perceived environment influences associated with physical activity in older Australians

Background, Regular physical activity in older adults can facilitate healthy aging, improve functional capacity, and prevent disease. However, factors associated with physical inactivity in older populations are poorly understood. This study attempts to identify social-cognitive and perceived environmental influences associated with physical activity participation in older populations. Methods. In a randomly selected sample of 449 Australian adults age 60 and older, we assessed self-reported physical activity and a range of social-cognitive and perceived environmental factors. Respondents were classified as sufficiently active and inactive based on energy expenditure estimates (kcal/week) derived from self-reported physical activity. Two logistic regression models, with and without self-efficacy included, were conducted to identify modifiable independent predictors of physical activity. Results. Significantly more males than females were physically active. Physical activity participation was related to age with a greater proportion of those age 65-69 being active than those age 60-64 or 70 or older. High self-efficacy, regular participation of friends and family, finding footpaths safe for walking, and access to local facilities were significantly associated with being active. Conclusion. Identifying predictors of physical activity in older populations, particularly social support, facility access, and neighbourhood safety, can inform the development of policy and intervention strategies to promote the health of older people. (C) 2000 American Health Foundation and Academic Press.

Developing a reliable audit instrument to measure the physical environment for physical activity

Background: The physical environment plays an important role in influencing participation in physical activity, although which factors of the physical environment have the greatest effect on patterns of activity remain to be determined. We describe the development of a comprehensive instrument to measure the physical environmental factors that may influence walking and cycling in local neighborhoods and report on its reliability. Methods: Following consultation with experts from a variety of fields and a literature search, we developed a Systematic Pedestrian and Cycling Environmental Scan (SPACES) instrument and used it to collect data over a total of 1987 kilometers of roads in metropolitan Perth, Western Australia. The audit instrument is available from the first author on request. Additional environmental information was collected using desktop methods and geographic information systems (GIS) technology. We assessed inter- and intra-rater reliability of the instrument among the 16 observers who collected the data. Results: The observers reported that the audit instrument was easy to use. Both inter- and intra-rater reliability of the environmental scan instrument were generally high. Conclusions: Our instrument provides a reliable, practical, and easy to-use method for collecting detailed street-level data on physical environmental factors that are potential influences on walking in local neighborhoods.

Promoting physical activity to older adults: a preliminary evaluation of three general practice-based strategies

The aim of this study was to explore the feasibility of an exercise scientist (ES) working in general practice to promote physical activity (PA) to 55 to 70 year old adults. Participants were randomised into one of three groups: either brief verbal and written advice from a general practitioner (GP) (G1, N=9); or individualised counselling and follow-up telephone calls from an ES, either with (G3, N=8) or without a pedometer (G2, N=11). PA levels were assessed at week 1, after the 12-wk intervention and again at 24 weeks. After the 12-wk intervention, the average increase in PA was 116 (SD=237) min/wk; N=28, p < 0.001. Although there were no statistically significant between-group differences, the average increases in PA among G2 and G3 participants were 195 (SD=207) and 138 (SD=315) min/wk respectively, compared with no change (0.36, SD=157) in G1. After 24 weeks, average PA levels remained 56 (SD=129) min/wk higher than in week 1. The small numbers of participants in this feasibility study limit the power to detect significant differences between groups, but it would appear that individualised counselling and follow-up contact from an ES, with or without a pedometer, can result in substantial changes in PA levels. A larger study is now planned to confirm these findings.

How can and do Australian doctors promote physical activity?

Background. Physical inactivity is recognized as an important public health issue. Yet little is known about doctors' knowledge, attitude, skills, and resources specifically relating to the promotion of physical activity. Our survey assessed the current practice, perceived desirable practice, confidence, and barriers related to the promotion of physical activity in family practice, Methods. A questionnaire was developed and distributed to all 1,228 family practitioners in Perth, Western Australia. Results. We received a 71% response (n = 789). Family practitioners are most likely to recommend walking to sedentary adults to improve fitness and they are aware of the major barriers to patients participating in physical activity. Doctors are less confident at providing specific advice on exercise and may require further skills, knowledge, and experience, Although they promote exercise to patients through verbal advice in the consultation, few use written materials or referral systems, Conclusions. There are significant differences between self-reports of current practice and perceived desirable practice in the promotion of physical activity by doctors, Future strategies need to address the self-efficacy of family physicians and involve resources of proven effectiveness. The potential of referral systems for supporting efforts to increase physical activity by Australians should be explored. (C) 1997 Academic Press.

Environmental factors associated with adults' participation in physical activity : A review

Background: Promoting physical activity is a public health priority, and changes in the environmental Contexts of adults' activity choices are believed to be crucial. However, of the factors associated with physical activity, environmental influences are among the least understood. Method: Using journal scans and computerized literature database searches, we identified 19 quantitative studies that assessed the relationships With physical activity behavior of perceived and objectively determined physical environment attributes. Findings were categorized into those examining five categories: accessibility of facilities, opportunities for activity, weather, safety, and aesthetic attributes. Results: Accessibility, opportunities, and aesthetic attributes had significant associations with physical activity, Weather and safety showed less-strong relationships. Where Studies pooled different categories to create composite variables, the associations were less likely to be statistically significant. Conclusions: Physical environment factors have consistent associations with physical activity behavior. Further development of ecologic and environmental models, together with behavior-specific and context-specific measurement strategies, should help in further understanding of these associations. Prospective Studies are required to identify possible causal relationships.

Reliability of moderate-intensity and vigorous physical activity stage of change measures for young adults

Background. The purpose of this study was to examine the reliability of stage of change (SOC) measures for moderate-intensity and vigorous physical activity in two separate samples of young adults. Staging measures have focused on vigorous exercise, but current public health guidelines emphasize moderate-intensity activity. Method. For college students in the USA (n = 105) and in Australia (n = 123), SOC was assessed separately on two occasions for moderate-intensity activity and for vigorous activity. Test-retest repeatability was determined, using Cohen's kappa coefficient. Results. In both samples, the reliability scores for the moderate-intensity physical activity staging measure were lower than the scores for the vigorous exercise staging measure. Weighted kappa values for the moderate-intensity staging measure were in the fair to good range for both studies (0.50 and 0.45); for the vigorous staging measure kappa values were excellent and fair to good (0.76 and 0.72). Conclusions. There is a need to standardize and improve methods for staging moderate-intensity activity, given that such measures are used in public health interventions targeting HEPA (health-enhancing physical activity). (C) 2003 American Health Foundation and Elsevier Science (USA). All rights reserved.

Test-retest reliability of four physical activity measures used in population surveys

Accurate monitoring of prevalence and trends in population levels of physical activity (PA) is a fundamental public health need. Test-retest reliability (repeatability) was assessed in population samples for four self-report PA measures: the Active Australia survey (AA, N=356), the short International Physical Activity Questionnaire (IPAQ, N=104), the physical activity items in the Behavioral Risk Factor Surveillance System (BRFSS, N=127) and in the Australian National Health Survey (NHS, N=122). Percent agreement and Kappa statistics were used to assess reliability of classification of activity status as 'active', 'insufficiently active' or 'sedentary'. Intraclass correlations (ICCs) were used to assess agreement on minutes of activity reported for each item of each survey and for total minutes. Percent agreement scores for activity status were very good on all four instruments, ranging from 60% for the NHS to 79% for the IPAQ. Corresponding Kappa statistics ranged from 0.40 (NHS) to 0.52 (AA). For individual items, ICCs were highest for walking (0.45 to 0.78) and vigorous activity (0.22 to 0.64) and lowest for the moderate questions (0.16 to 0.44). All four measures provide acceptable levels of test-retest reliability for assessing both activity status and sedentariness, and moderate reliability for assessing total minutes of activity.

Screening for physical activity in family practice - Evaluation of two brief assessment tools

Background: Physical activity (PA) is relevant to the prevention and management of many health conditions in family practice. There is a need for an efficient, reliable, and valid assessment tool to identify patients in need of PA interventions. Methods: Twenty-eight family physicians in three Australian cities assessed the PA of their adult patients during 2004 using either a two- (2Q) or three-question (3Q) assessment. This was administered again approximately 3 days later to evaluate test-retest reliability. Concurrent validity was evaluated by measuring agreement with the Active Australia Questionnaire, and criterion validity by comparison with 7-day Computer Science Applications, Inc. (CSA) accelerometer counts. Results: A total of 509 patients participated, with 428 (84%) completing a repeat assessment, and 415 (82%) accelerometer monitoring. The brief assessments had moderate test-retest reliability (2Q k = 58.0%, 95% confidence interval [CI] = 47.2-68.8%; 3Q k = 55.6%, 95% CI = 43.8-67.4%); fair to moderate concurrent validity (2Q k = 46.7%, 95% CI = 35.657.9%; 3Q k = 38.7%, 95% CI = 26.4-51.1%); and poor to fair criterion validity (2Q k = 18.2%, 95% CI = 3.9-32.6%; 3Q k = 24.3%, 95% CI = 11.6-36.9%) for identifying patients as sufficiently active. A four-level scale of PA derived from the PA assessments was significantly correlated with accelerometer minutes (2Q rho = 0.39, 95% CI = 0.28-0.49; 3Q rho = 0.31, 95% CI = 0.18-0.43). Physicians reported that the assessments took I to 2 minutes to complete. Conclusions: Both PA assessments were feasible to use in family practice, and were suitable for identifying the least active patients. The 2Q assessment was preferred by clinicians and may be most appropriate for dissemination.

Reliability and validity of a brief physical activity assessment for use by family doctors

Objective: To evaluate the reliability and validity of a brief physical activity assessment tool suitable for doctors to use to identify inactive patients in the primary care setting. Methods: Volunteer family doctors (n = 8) screened consenting patients (n = 75) for physical activity participation using a brief physical activity assessment tool. Inter-rater reliability was assessed within one week (n = 71). Validity was assessed against an objective physical activity monitor (computer science and applications accelerometer; n = 42). Results: The brief physical activity assessment tool produced repeatable estimates of sufficient total physical activity, correctly classifying over 76% of cases (kappa 0.53, 95% confidence interval (CI) 0.33 to 0.72). The validity coefficient was reasonable (kappa 0.40, 95% CI 0.12 to 0.69), with good percentage agreement (71%). Conclusions: The brief physical activity assessment tool is a reliable instrument, with validity similar to that of more detailed self report measures of physical activity. It is a tool that can be used efficiently in routine primary healthcare services to identify insufficiently active patients who may need physical activity advice.

Promoting physical activity in Australian general practices: a randomised trial of health promotion advice versus hypertension management

A randomised controlled trial was conducted to determine if physicians' advice to promote physical activity to patients was more effective if the advice was tailored to the management of hypertension, compared with more general health promotion advice. Participants included inactive 40- to 70-year-old patients visiting the physicians' during study recruitment period. Physicians provided verbal physical activity advice and written materials, both tailored to either general health promotion messages or specifically as a means for treating or managing hypertension. Seventy-five physicians and 98% (767/780) of screened eligible patients participated in the study. Differences between intervention and control groups self-reported physical activity were assessed over 6 months. Follow-up response rates were 92 and 84% at the 2- and 6-month assessments. There were no consistent, significant differences between groups at the 2- or 6-month assessments. Thus, neither intervention strategy resulted in significant changes in patients self-reported physical activity, regardless of the whether the advice was tailored to hypertension management or general health promotion advice. (c) 2004 Elsevier Ireland Ltd. All rights reserved.

Dissemination of a community-based physical activity project: The case of 10,000 steps

This paper describes the use of a web-site for the dissemination of the community-based '10,000 steps' program which was originally developed and evaluated in Rockhampton, Queensland in 2001-2003. The website provides information and interactive activities for individuals, and promotes resources and programs for health promotion professionals. The dissemination activity was assessed in terms of program adoption and implementation. In a 2-year period (May 2004-March 2006) more than 18,000 people registered as users of the web-site (togging more than 8.5 billion steps) and almost 100 workplaces and 13 communities implemented aspects of the 10,000 steps program. These data support the use of the internet as an effective means of disseminating ideas and resources beyond the geographical borders of the original project. Following this preliminary dissemination, there remains a need for the systematic study of different dissemination strategies, so that evidence-based physical activity programs can be translated into more widespread public health practice. (c) 2006 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Reliability of a measure of prediagnosis physical activity for cancer survivors

Purpose: This study was conducted to examine the test-retest reliability of a measure of prediagnosis physical activity participation administered to colorecial cancer survivors recruited from a population-based state cancer registry. Methods: A total of 112 participants completed two telephone interviews. I month apart, reporting usual weekly physical activity in the year before their cancer diagnosis. Intraclass correlation coefficients (ICC) and standard en-or of measurement (SEM) were used to describe the test-retest reliability of the measure across the sample: the Bland-Altman approach was used to describe reliability at the individual level. The test-retest reliability for categorized total physical activity (active, insufficiently active, sedentary) was assessed using the kappa statistic. Results: When the complete sample was considered, the ICC ranged from 0.40 (95% Cl: 0.24, 0.55) for vigorous gardening to 0.77 (95% Cl: 0.68, 0.84) for moderate physical activity. The SEM, however, were large. indicating high measurement error. The Bland-Altman plots indicated that the reproducibility of data decreases as the aniount of physical activity reported each week increases The kappa coefficient for the categorized data was 0.62 (95% Cl: 0.48, 0.76). Conclusion: Overall. the results indicated low levels of repeatability for this measure of historical physical activity. Categorizing participants as active, insufficiently active, or sedentary provides a higher level of test-retest reliability.

The association between number of homework assignments completed during a lifestyle physical activity intervention and scores on transtheoretical measures

An assumption of theory-based physical activity interventions is that active participation positively affects the theoretical constructs upon which the intervention is based. This assumption is rarely tested. This study assessed whether participation, defined as completion of homework, in a lifestyle physical activity intervention was associated with changes over 6 months in constructs the homework addressed: the behavioral and cognitive processes of change, self-efficacy, and decisional balance (the pros and cons). Participants were 244 sedentary adults aged 25 to 75 years. They completed an average of 12 of 20 homework assignments. Those completing at least two-thirds of the homework (n = 113) had greater changes in the theoretical constructs from pretest to posttest than those completing less (n = 90). Post-hoc analyses suggest that completing theory-based homework may impact the processes of change and self-efficacy in lifestyle physical activity interventions and, therefore, are warranted in future interventions.

Using Rasch modeling to re-evaluate three scales related to physical activity: Enjoyment, perceived benefits and perceived barriers

Studies suggest that enjoyment, perceived benefits and perceived barriers may be important mediators of physical activity. However, the psychometric properties of these scales have not been assessed using Rasch modeling. The purpose of this study was to use Rasch modeling to evaluate the properties of three scales commonly used in physical activity studies: the Physical Activity Enjoyment Scale, the Benefits of Physical Activity Scale and the Barriers to Physical Activity Scale. The scales were administered to 378 healthy adults, aged 25–75 years (50% women, 62% Whites), at the baseline assessment for a lifestyle physical activity intervention trial. The ConQuest software was used to assess model fit, item difficulty, item functioning and standard error of measurement. For all scales, the partial credit model fit the data. Item content of one scale did not adequately cover all respondents. Response options of each scale were not targeting respondents appropriately, and standard error of measurement varied across the total score continuum of each scale. These findings indicate that each scale's effectiveness at detecting differences among individuals may be limited unless changes in scale content and response format are made.