Biomedical subjects

Katrina D Dubose

Publications and source records attributed to Katrina D Dubose.

5 recordsLinked to original sources

PubMed2007

Discrepancies between methods of identifying objectively determined physical activity.

UNLABELLED: Current methods for validating physical activity (PA) questionnaires typically use accelerometers as objective measures for comparison with questionnaire responses and obtain low correlations or agreement. PURPOSE: We examined possible reasons for weak associations in validation studies by comparing published ActiGraph accelerometer intensity cut points with cut points based on intensity thresholds for heart rate response to PA. METHODS: Twelve adults (five men, seven women; age 31.0 +/- 14.3 yr) wore an ActiGraph accelerometer and a Polar Vantage NV heart watch simultaneously for seven consecutive days during their waking hours. We identified PA bouts from the minute-by-minute ActiGraph data using published accelerometer thresholds for defining moderate- and vigorous-intensity PA. We then compared PA bout intensities identified with these criteria with intensity classifications of the PA bouts using mean percent heart rate reserve (HRR). RESULTS: Most of the moderate-intensity PA bouts identified by the Freedson (78.3%), Swartz (88.0%), and Hendelman (94.7%) ActiGraph cut points were associated with a mean %HRR < 45% (very light and light intensities). The estimated mean frequency with which study participants engaged in moderate-intensity PA varied with the cut points and type of bouts used and ranged from 1.1 d.wk(-1) (45-60%HRR) to 7.0 d.wk(-1) (Hendelman cut points). The mean total duration on active days ranged from 17.9 min.d(-1)(45-60%HRR) to 139.2 min.d(-1) (Hendelman cut points). Fewer bouts of vigorous PA were found in the accelerometer data, and most were in the vigorous-intensity category of > or = 60%HRR. CONCLUSIONS: The method used for analyzing ActiGraph activity data can result in large differences in the summary measure of minutes of moderate- to vigorous-intensity activity.

Adult↗

PubMed2005

Reliability and validity of the occupational physical activity questionnaire.

INTRODUCTION: Few questionnaires have been designed for wide-scale, population-based surveillance of occupational physical activity (PA) behaviors. PURPOSE: This study was conducted to determine the test-retest reliability and validity of the Occupational Physical Activity Questionnaire (OPAQ) designed to assess the usual weekly duration of occupational sitting or standing, walking, and heavy labor activities. METHODS: Analyses were based on a convenience sample of 41 adults (13 men, 28 women) (mean+/- SD, 38.8+/- 9.9 yr) who worked in a broad range of occupations. Intraclass correlation coefficients (ICC) were used to evaluate the 2-wk test-retest reliability of the OPAQ. Spearman correlations were used to assess criterion (occupational PA record, Actigraph) and construct (cardiorespiratory fitness, percent body fat) related validity. Convergent validity with the current Behavioral Risk Factor Surveillance System (BRFSS) occupational PA question was evaluated with the kappa coefficient. RESULTS: The 2-wk test-retest reliability coefficients for the OPAQ hours per week ranged from an ICC of 0.55 to 0.91. Fair-to-substantial criterion validity was observed for like activities on the OPAQ and a detailed 7-d occupational PA record for sitting or standing (r=0.37), walking (r=0.74), and heavy labor activity (r=0.31). OPAQ walking was related to PA record moderate-intensity PA (r=0.41), Actigraph occupational light-intensity counts (r=0.41), and Actigraph total counts (r=0.44). Associations observed between the OPAQ and submaximal exercise heart rate or percent body fat were low (r=-0.17 to 0.32). Convergent validity displaying the ability of the OPAQ to correctly identify participants who performed mostly sitting or standing, mostly walking, or mostly heavy labor at work was substantial [kappa=0.71 (95% CI=0.49, 0.94)]. CONCLUSIONS: The test-retest reliability and validity of the OPAQ are similar to other established occupational PA questionnaires. This preliminary study supports the use of the OPAQ in research and surveillance settings.

Adult↗

PubMed2004

A preliminary study of one year of pedometer self-monitoring.

BACKGROUND: Long-term pedometer monitoring has not been attempted. PURPOSE: The purpose of this project was to collect 365 days of continuous self-monitored pedometer data to explore the natural variability of physical activity. METHODS: Twenty-three participants (7 men, 16 women; M age = 38 +- 9.9 years; M body mass index = 27.7 +- 6.2 kg/m2) were recruited by word of mouth at two southern U.S. universities. Participants were asked to wear pedometers at their waist during waking hours and record steps per day and daily behaviors (e.g., sport/exercise, work or not) on a simple calendar. In total, participants wore pedometers and recorded 8,197 person-days of data (of a possible 8,395 person-days, or 98%) for a mean of 10,090 +- 3,389 steps/day. Missing values were estimated using the Missing Values Analysis EM function in SPSS, Version 11.0.1. RESULTS: A mean of 10,082 +- 3,319 steps/day was computed. Using the corrected data, differences in steps/day were significant for season (summer > winter, F = 7.57, p = .001), day of the week (weekday > weekend, F = 3.97, p = .011), type of day (workday vs. nonworkday, F = 9.467, p = .008), and participation in sport/exercise (day with sport/exercise > day without sport/exercise, F = 102.5, p < .0001). CONCLUSIONS: These data suggest that surveillance should be conducted in the spring/fall or that an appropriate correction factor should be considered if the intent is to capture values resembling the year-round average.

Adult↗

PubMed2004

Nonoccupational physical activity by degree of urbanization and U.S. geographic region.

PURPOSE: To estimate levels of nonoccupational leisure-time physical activity (LTPA) by degree of urbanization and geographic region of the United States. METHODS: Participants were respondents to the Behavioral Risk Factor Surveillance System (BRFSS) in 2001 (N = 137,359). Moderate- and vigorous-intensity LTPA was categorized as meeting recommended levels, insufficient, or inactive. The U.S. Department of Agriculture rural-urban continuum codes were used to describe degrees of urbanization (metro, large urban, small urban, and rural). Geographic regions were defined by the U.S. Bureau of the Census (Northeast, Midwest, South, and West). Prevalence estimates were calculated using sample weights to account for the design of the BRFSS. Multivariate logistic regression analyses examined regional differences in the odds of physical inactivity (physically inactive vs insufficient or meets) by degree of urbanization after adjustment for sex, age, race, BMI, education, and occupational physical activity. RESULTS: Large urban areas (49.0%) and the western United States (49.0%) had the highest prevalence of recommended levels of LTPA. Rural areas (24.1%) and the southern United States (17.4%) had the highest prevalence of inactivity. Adults living in the four urbanization categories of the midwestern (metro (OR = 1.47, 95% CI = 1.31, 1.65), large urban (OR = 1.83, 95% CI = 1.51, 2.23), small urban (OR = 1.99, 95% CI = 1.65, 2.40), and rural (OR = 2.59, 95% CI = 1.35, 4.97)); and southern (metro (OR = 1.70, 95% CI = 1.53, 1.88), large urban (OR = 2.04, 95% CI = 1.72, 2.41), small urban (OR = 2.32, 95% CI = 2.02, 2.67), and rural (OR = 5.49, 95% CI = 2.82, 10.68)) U.S. regions were more likely to be inactive than adults living in similar areas of the western United States. Adults in northeast metro and large urban areas (OR = 1.62, 95% CI = 1.45, 1.81; and OR = 1.37, 95% CI = 1.08, 1.74, respectively) were more likely to be inactive than those residing in western metro and large urban areas. CONCLUSION: The prevalence of physical inactivity varies by degree of urbanization and geographic region of the United States.

Activities of Daily Living↗

PubMed2003

Evaluation of a two-part survey item to assess moderate physical activity: the Cross-Cultural Activity Participation Study.

PURPOSE: This study evaluated a two-part survey item that assessed adherence to the national moderate physical activity (MPA) recommendation (>/=30 min/day on >/=5 days/week). METHODS: Participants were African American (n = 137), Native American (n = 129), and Caucasian (n = 50) women >/= 40 years from South Carolina and New Mexico, who were participating in a study validating physical activity surveys. The survey item was compared with data obtained from MPA recorded in PA records (min/day), Caltrac accelerometers (Muscle Dynamics, Torrance, CA) (kcal/day), and pedometers (steps/day). RESULTS: Approximately 64% of the participants reported meeting the MPA recommendation on the survey item. Adjusted analyses showed that those who reported meeting the recommendation were more active than those who reported not meeting the recommendation (109.2 vs. 83.9 min/day, 2171.2 vs. 2088.4 kcal/day, and 5795.7 vs. 4797.2 steps/day, respectively; all p < 0.0001). The types of activities recorded in the PA record did not differ by self-reported adherence to the MPA recommendation except for walking (25.2 vs. 14.0 min/day for those who reported meeting vs. not meeting the recommendation, respectively; p < 0.05). A higher proportion of those who reported meeting the recommendation also reported participating in conditioning activities compared with those who reported not meeting the recommendation (31% vs. 19%, respectively; p < 0.05). CONCLUSIONS: The two-part survey item can reliably differentiate between higher and lower levels of activity. Those who perceive themselves as meeting the MPA recommendation are, on average, likely to have higher activity levels than those who perceive that they do not meet the recommendation.

Activities of Daily Living↗