Date of Award

Summer 2008

Document Type


Degree Name

Doctor of Philosophy (PhD)


Health Services Research

Committee Director

Stacey Plichta

Committee Member

Clare Houseman

Committee Member

Fran Butterfoss


This study examined the usefulness of the Theory of Planned Behavior to predict how attitude, subjective norm, perceived behavioral control, and intention are associated with physical activity in longshoremen from the Hampton Roads Shipping Association-International Longshoreman's Association (HRSA-ILA). The study was conducted in two phases. In the first phase, five focus groups were conducted to elicit information about the health behaviors of longshoremen. From the results of these focus groups, a 90-question, theory based, self-reported questionnaire was developed to identify beliefs, attitudes, subjective norms, perceived behavioral control, and intentions that contribute to longshoremen engaging in physical activity. In the second phase, the questionnaire was used in an observational cross-sectional survey design. A convenience sample of 687 longshoremen was invited to participate; 404 longshoremen completed the survey for a 59% response rate.

The relationship of the theory constructs (direct and indirect attitudes, direct and indirect subjective norms, and direct and indirect perceived behavioral control) and relevant demographic variables to the dependent variable (physical activity, intention) was tested with multiple linear regression models. The model was a significant predictor of physical activity behavior with both active and retired members. The model was also a significant predictor of intention to exercise. When the demographic variables of age, gender, ethnicity, educational level, marital status, income, and years in the HRSA-ILA were added to the physical activity multiple linear regression model for active and retired members, the model was statistically significant. There was an increase in the total amount of variance, suggesting that even though demographic variables were not part of the theory, they provide important information for this group.

Path analysis for physical activity for active male members was statistically significant with the path from direct perceived behavioral control and intention providing a direct effect. The results for retired male members were statistically significant with the path from direct subjective norm providing a direct effect. For intention, the results for active male members were significant with the path from direct attitudes, indirect attitudes, direct perceived behavioral control, and indirect perceived behavioral control providing a direct effect. Retired members were statistically significant with the path from direct attitudes, indirect subjective norm and direct perceived behavioral control achieving a significant relationship suggesting a direct effect. Direct perceived behavioral control provided a direct effect with 3 of the 4 groups with the exception of physical activity for retired members. These findings are consistent with the theory model.

Many health risks can be mitigated if physical activity behaviors are adopted and maintained. Further research is needed to study strategies to assist members to move from behavioral intentions to targeted actions that improve the likelihood of engaging in physical activity. When health beliefs that influence behavior are known, disease prevention and health promotion information and activities can be targeted to the population to help promote healthier more active lifestyles.