Traditional physical activity indexes derived from the Harvard alumni activity survey have low construct validity in a lower income, urban population

Predicting risk on cardiovascular or cerebrovascular disease based on a physical activity cohort: Results from APAC study

Commonly used prediction models have been primarily constructed without taking physical activity into account. Using the Kailuan physical activity cohorts from Asymptomatic Polyvascular Abnormalities in Community (APAC) study, we developed a 9-year cardiovascular or cerebrovascular disease (CVD) risk prediction equation. Participants in this study were included from APAC cohort, which included 5440 participants from the Kailuan cohort in China. Cox proportional hazard regression model was applied to construct sex-specific risk prediction equations for the physical activity cohort (PA equation). Proposed equations were compared with the 10-year risk prediction model, which is developed for atherosclerotic cardiovascular disease risk in Chinese cohorts (China-PAR equation). C statistics of PA equations were 0.755 (95% confidence interval, 0.750-0.758) for men and 0.801 (95% confidence interval, 0.790-0.813) for women. The estimated area under the receiver operating characteristic curves in the validation set shows that the PA equations perform as good as the China-PAR. From calibration among four categories of predicted risks, the predicted risk rates by PA equations were almost identical to the Kaplan-Meier observed rates. Therefore, our developed sex-specific PA equations have effective performance for predicting CVD for physically active cohorts in the physical activity cohort in Kailuan.

Reliability and concurrent and construct validity of the Strategies for Weight Management measure for adults

INTRODUCTION

This study evaluates the reliability and validity of the strategies for weight management (SWM) measure, a questionnaire that assesses weight management strategies for adults. The SWM includes 20 items that are categorized within the following subscales: (1) energy intake, (2) energy expenditure, (3) self-monitoring, and (4) self-regulation.

METHODS

Baseline and 6-month data were collected from 404 overweight/obese adults (mean age=22±3.8 years, 68% ethnic minority) enrolled in a randomized controlled trial aiming to reduce weight by improving diet and physical activity behaviours. Reliability and validity were assessed for each subscale separately. Cronbach alpha was conducted to assess reliability. Concurrent, construct I (sensitivity to the study treatment condition), and construct II (relationship to the outcomes) validity were assessed using linear regressions with the following outcome measures: weight, self-reported diet, and weekly energy expenditure.

RESULTS

All subscales showed strong internal consistency. The strength of the validity evidence depended on subscale and validity type. The strongest validity evidence was concurrent validity of the energy intake and energy expenditure subscales; construct I validity of the energy intake and self-monitoring subscales; and construct II validity of the energy intake, energy expenditure, and self-regulation subscales.

CONCLUSIONS

Results indicate that the SWM can be used to assess weight management strategies among an ethnically diverse sample of adults as each subscale showed evidence of reliability and select types of validity. As validity is an accumulation of evidence over multiple studies, this study provides initial reliability and validity evidence in one population segment.

Energy Metabolism and the Burden of Multimorbidity in Older Adults: Results From the Baltimore Longitudinal Study of Aging

Excessively elevated resting metabolic rate (RMR) for persons of a certain age, sex, and body composition is a mortality risk factor. Whether elevated RMR constitutes an early marker of health deterioration in older adult has not been fully investigated. Using data from the Baltimore Longitudinal Study of Aging, we hypothesized that higher RMR (i) was cross-sectionally associated with higher multimorbidity and (ii) predicted higher multimorbidity in subsequent follow-ups. The analysis included 695 Baltimore Longitudinal Study of Aging participants, aged 60 or older at baseline, of whom 248 had follow-up data available 2 years later and 109 four years later. Multimorbidity was assessed as number of chronic diseases. RMR was measured by indirect calorimetry and was tested in regression analyses adjusted for covariates age, sex, and dual-energy x-ray absorptiometry-measured total body fat mass and lean mass. Baseline RMR and multimorbidity were positively associated, independent of covariates (p = .002). Moreover, in a three-wave bivariate autoregressive cross-lagged model adjusted for covariates, higher prior RMR predicted greater future multimorbidity above and beyond the cross-sectional and autoregressive associations (p = .034). RMR higher than expected, given age, sex, and body composition, predicts future higher multimorbidity in older adults and may be used as early biomarker of impending health deterioration. Replication and the development of normative data are required for clinical translation.

Association between energy availability and physical activity in older adults

OBJECTIVE

Age-related declines in physical activity are commonly observed in human and animal populations, but their physiologic bases are not fully understood. The authors hypothesize that a lack of available energy contributes to low levels of activity in older persons.

DESIGN

Cross-sectional analyses of relationships between physical activity level and energy availability were performed in 602 community-dwelling volunteers aged 45-91 yrs from the Baltimore Longitudinal Study of Aging. Energy expenditure was measured at rest and during a maximal 400-m walk for calculation of "available energy." Overall and vigorous physical activity levels were assessed using standardized questionnaires. General linear regression models were used to assess the relationships between available energy and general and vigorous physical activity, and stratified analyses were used to analyze the possible differential association between available energy and physical activity across high and low (peak sustained walking oxygen consumption per unit time, <18.3 ml of oxygen per kilogram per minute) levels of aerobic fitness.

RESULTS

Low available energy was associated with low levels of total physical activity (β = 64.678, P = 0.015) and vigorous activity (β = 9.123, P < 0.0001). The direct relationship between available energy and physical activity was particularly strong in persons categorized as having low aerobic fitness between available energy and physical activity with both total (β = 119.783, P = 0.022) and vigorous activity (β = 10.246, P = 0.015) and was independent of body composition and age.

CONCLUSIONS

The findings from this study support the hypothesis that available energy promotes the maintenance of physical activity in older persons. The findings also run counter to the perception that age-related declines in physical activity are primarily societally or behaviorally driven.

Differential accuracy of physical activity self-report by body mass index

OBJECTIVES

To examine whether agreement between self-reported and accelerometer-measured physical activity varies by BMI category in a low-income black sample.

METHODS

Participants completed a questionnaire and wore an accelerometer for 4-6 days. Using one- and 10-minute bouts, accelerometers measured light, moderate, and vigorous physical activity time.

RESULTS

Correlations varied by obesity (nonobese: one-minute r=0.41; 10-minute r=0.47; obese: one-minute r=0.21; 10-minute r=0 .14). Agreement was highest among nonobese persons (one-minute kappa = 0.48, 10-minute kappa = 0.023; obese: one-minute kappa = -0.024, 10- minute kappa = -0.020).

CONCLUSIONS

We found compromised questionnaire performance among obese participants.

Physical activity in US Blacks: a systematic review and critical examination of self-report instruments

Background

Physical activity self-report instruments in the US have largely been developed for and validated in White samples. Despite calls to validate existing instruments in more diverse samples, relatively few instruments have been validated in US Blacks. Emerging evidence suggests that these instruments may have differential validity in Black populations.

Purpose

This report reviews and evaluates the validity and reliability of self-reported measures of physical activity in Blacks and makes recommendations for future directions.

Methods

A systematic literature review was conducted to identify published reports with construct or criterion validity evaluated in samples that included Blacks. Studies that reported results separately for Blacks were examined.

Results

The review identified 10 instruments validated in nine manuscripts. Criterion validity correlations tended to be low to moderate. No study has compared the validity of multiple instruments in a single sample of Blacks.

Conclusion

There is a need for efforts validating self-report physical activity instruments in Blacks, particularly those evaluating the relative validity of instruments in a single sample.

Physical activity questionnaires for adults: a systematic review of measurement properties

Many questionnaires have been developed to measure physical activity (PA), but an overview of the measurement properties of PA questionnaires is lacking. A summary of this information is useful for choosing the best questionnaire available. Therefore, the objective of this study was to evaluate and compare measurement properties of self-administered questionnaires assessing PA in adults. We searched MEDLINE, EMBASE and SportDiscus, using 'exercise', 'physical activity', 'motor activity' and 'questionnaire' as keywords. We included studies that evaluated the measurement properties of self-report questionnaires assessing PA. Article selection, data extraction and quality assessment were performed by two independent reviewers. The quality and results of the studies were evaluated using the Quality Assessment of Physical Activity Questionnaires (QAPAQ) checklist. Construct validity, reliability and responsiveness were rated as positive, negative or indeterminate, depending on the methods and results. We included 85 (versions of) questionnaires. Overall, the quality of the studies assessing measurement properties of PA questionnaires was rather poor. Information on content validity was mostly lacking. Construct validity was assessed in 76 of the questionnaires, mostly by correlations with accelerometer data, maximal oxygen uptake or activity diaries. Fifty-one questionnaires were tested for reliability. Only a few questionnaires had sufficient construct validity and reliability, but these need to be further validated. Responsiveness was studied for only two questionnaires and was poor. There is a clear lack of standardization of PA questionnaires, resulting in many variations of questionnaires. No questionnaire or type of questionnaire for assessing PA was superior and therefore could not be strongly recommended above others. In the future, more attention should be paid to the methodology of studies assessing measurement properties of PA questionnaires and the quality of reporting.

Psychometric properties of the KPAS in diverse ethnic groups of midlife women

The Kaiser Physical Activity Survey (KPAS), designed specifically for diverse activity domains (housework, caregiving, occupational activity), is used to assess physical activity among multiethnic midlife women. This study evaluates KPAS reliability and validity (not widely documented) in measuring physical activity among 341 groups in this classification. Internal consistency coefficients are adequate for all ethnic groups except non-Hispanic (N-H) African Americans. To evaluate construct validity, the researchers use multiple analytic approaches, including correlation between behavioral intention and KPAS scores and factor analysis. KPAS scores correlate positively with behavioral intention scores among all ethnic groups. Eight factors are extracted among all groups except N-H Asian Americans. In the convergent validity test, N-H African Americans and N-H Asian Americans show unique patterns. Overall, the KPAS proves reliable as a reasonably accurate instrument to assess physical activities among multiethnic groups of midlife women. However, cultural sensitivity among N-H African Americans and N-H Asian Americans needs further examination.