The goal of this dissertation study was to examine the influence of individual values on fruit and vegetable consumption of colorectal cancer survivors and non-affected persons. This dissertation research was a secondary analysis of data obtained from the North Carolina Strategies for Improving Diet, Exercise, and Screening (NC STRIDES, PI: Marci Kramish Campbell), a population-based study of colorectal cancer risk prevention in a 33-county area of North Carolina. Participants in the NC STRIDES study were originally recruited from the North Carolina Colon Cancer Study (NCCCS). A detailed description of the NCCCS study can be found elsewhere (Satia et al., 2004).
The dissertation study was conducted using quantitative and qualitative approaches for descriptive/interpretive and explanatory purposes. Paper One assessed the relationships between values and fruit and vegetable consumption for colorectal cancer survivors and non-affected persons. Specifically, the baseline and follow-up data were used to (1) examine socio-demographic factors associated with values and fruit and vegetable intake, (2) assess the role of values in fruit and vegetable changes over time, and (3) assess the role of values in other psychosocial changes (individual motivation). Paper Two used a purposeful stratified sampling approach to examine in greater detail the relationships presented in the conceptual model. Specifically, the purpose of using qualitative data in this study was to expand the examination of how values may operate in promoting changes in fruit and vegetable consumption. Jointly, the two approaches contribute to public health practice by: (1) providing information about whether dietary intake can be explained by differences in values and the underlying factors that relate to how values influence behaviors; (2) adding to the
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scholarship on the use of motivational interviewing for health promotion; and (3) improving future colorectal cancer control and prevention interventions that use a values approach as a health communications tool. Approval for this dissertation study was obtained from the Institutional Review Board of the School of Public Health at the University of North Carolina at Chapel Hill.
Parent Study Population
A total of 835 participants were randomized to one of the following year-long interventions: (1) four tailored print materials (TPCs only); (2) four tailored motivational interviews (TMI only); (3) four tailored print materials and four motivational interviews (COMBINED); and (4) general health
information materials (CONTROL). NC STRIDES participants completed all surveys via the telephone: a baseline survey and a follow-up survey (after 12 months). At follow-up, 735 participants completed the study (90% completion rate). Because personally held values were only assessed in the Tailored Motivational Interviewing (TMI) arms of the NC STRIDES study population (N =366), the sample of interest for this dissertation study was restricted to participants in the TMI groups (TMI only and COMBINED). In addition to receiving the baseline and follow-up surveys, participants randomized into the TMI arms received four motivational interviewing counseling calls approximately 20-30 minutes long. Two months after the baseline study was conducted, participants received the first call. The second, third, and fourth calls occurred during months 4, 6, and 9 respectively.
Motivational Interviewing (MI) calls
The motivational interviewing calls were conducted via the telephone. Telephone counselors were doctoral students at UNC School of Public Health trained in motivational interviewing. Following the training, interviewers conducted practice interviews with participants not enrolled in the current study and these were audio-taped and reviewed for adherence to the protocol. The project manager supervised the telephone counselors and monitored the calling on an ongoing basis to ensure quality.
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Participants received four motivational interviewing calls lasting about 20-30 minutes. Only one call focused on fruit and vegetable consumption.
Motivational interviewing is client-centered and uses skills such as listening and reflecting to help the participant find a solution that fits with their own goals and lifestyle. However, being client- centered does not mean that the topic of conversation is random. Rather, being client-centered ensures that the participant’s concerns, fears, knowledge, and motivations direct the conversation and that the participant determines what changes, if any, will occur. As such, the telephone interviewers used a “roadmap” developed by the NC STRIDES staff. The roadmap is shown in Figure 2. It allowed for support of participants in articulating the importance of dietary change, barriers to making changes, a plan of action, and factors that may increase the participant’s chances of succeeding in any nutrition goal set. The “roadmap” also balanced the need to control costs and maintain quality in using brief telephone-base motivational interviewing in a randomized control trial. This protocol allowed for standardization and flexibility to incorporate the reflective listening, open-ended questions, and client- led discussion that are the hallmarks of motivational interviewing. The script blended the vocabulary and techniques of motivational interviewing with the needs of the NC STRIDES research objectives of addressing the health behaviors under study.
All motivational interviews were taped recorded with the permission of participants. A random sample of these tapes was monitored by the project manager for consistency, appropriateness of probing, relevant interviewing attributes, and adherence to spirit of motivational interviewing. These steps were in place to identify and control for any potential threats to internal validity (Pedhazur & Schmelkin, 1991).
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The structured section of the values inquiry during the motivational interviewing calls is provided in Table 1 below. Table 2 provides the list of values used during the values clarification exercise. Figure 3 shows the fruit/vegetable importance and confidence scale.
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Figure 2. NC STRIDES Roadmap Protocol for the Tailored Motivational Interviewing Call INTRODUCTION
Identify project Indicate when they did survey Check they received phone card
Remind of letter/4 calls ASK PERMISSION TO TAPE RECORD