Last Modified

• March 22, 2019

Creator

• Close, Michael
  • Affiliation: Gillings School of Global Public Health, Department of Health Behavior

Abstract

• Sufficient engagement in physical activity is important in reducing the prevalence of activity-linked chronic disease among office workers. The dissertation research, presented through three manuscripts, leverages baseline data from a worksite nutrition intervention study to identify and describe segments of office workers by activity patterns, with the purpose of informing workplace physical activity programming. In Manuscript One, latent class analysis was used to identify segments of office workers by self-reported types of usual activity behaviors (n = 239). In addition, demographic characteristics and objectively measured levels of physical activity associated with segment membership were examined. A two-class model indicative of “exerciser” (50.2%) and “non-exerciser” (49.8%) segments fit best. Those with a Bachelor’s degree or higher (vs. less than Bachelor’s degree) were more likely to be a member of the “exerciser” segment, while women (vs. men) were less likely to belong to the “exerciser” segment. In the fully adjusted model, minutes of weekly moderate-vigorous physical activity were more than two times higher for the “exerciser” segment (mean = 209.5 minutes; SE = 13.5) than the “non-exerciser” segment (mean = 77.5; SE = 4.0). In Manuscript Two, the relationship between segment membership and body mass index was evaluated. In the full model, membership to the “exerciser” segment was associated with significantly lower mean body mass index (mean = 29.0; SE = 0.6) as compared to the “non-exerciser” segment (mean = 35.1; SE = 0.9). In Manuscript Three, the predictive validity and test-retest reliability of the self-report physical activity instrument used to collect data for segmentation was evaluated. In the evaluation of predictive validity, the instrument showed reasonably strong overall Spearman correlations in short (rho = 0.35 – 0.40) and long-term (rho = 0.26 – 0.33) timeframes. The overall test-retest reliability of the instrument within an approximate six-month timeframe was also adequate (rho = 0.54 – 0.59). Stratified analyses showed minimal differences in predictive validity and test-retest reliability by age, weight status, and sex. The overall dissertation findings shed light on the heterogeneity in activity engagement found in the workplace and also contribute to the research examining the psychometric properties of self-reported physical activity instruments.

Date of publication

• May 2018

Keyword

• Public health

DOI

• https://doi.org/10.17615/gp7y-f666

Resource type

• Dissertation

Advisor

• Linnan, Laura
• Viera, Anthony
• Lytle, Leslie
• Chen, Ding-Geng
• Valle, Carmina

Degree

• Doctor of Philosophy

Degree granting institution

• University of North Carolina at Chapel Hill Graduate School

Graduation year

• 2018

Language

• English

Parents:

This work has no parents.

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