Publication Date

2014-12-04

Availability

Embargoed

Embargo Period

2016-12-04

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PHD)

Department

Epidemiology (Medicine)

Date of Defense

2014-11-07

First Committee Member

David Lee

Second Committee Member

Mark Stoutenberg

Third Committee Member

Kristopher Arheart

Fourth Committee Member

Noella Dietz

Fifth Committee Member

Kathryn Schmitz

Abstract

Background: Breast cancer (BCa) is the most common type of cancer diagnosed among women in the United States. Advances in cancer detection and treatment have led to improved survival, and focus has shifted towards addressing the adverse physiological and psychological effects associated with BCa and its treatments. Evidence supports regular physical activity (PA) as an effective means of managing the negative side effects of BCa treatments and improving health-related quality of life (QOL). Strength training is of particular importance for BCa survivors who experience treatment-related functional limitations. Despite this fact, PA levels among BCa survivors are below those recommended for health, and decline further after diagnosis. Healthcare professionals (HCP) have been considered an ideal source for exercise promotion; nonetheless, an inadequate number of HCPs recommend PA to their BCa patients. As such, there is a need to identify new mediums for delivering exercise information and instruction programming that incorporate BCa survivors’ preferences and can be easily used by HCPs to encourage PA among their patients. Methods: Two studies were conducted successively. Study 1 was a qualitative anslysis in which female BCa survivors were asked to view a DVD-based exercise program prior to attending one of five focus groups. A semi-structured guide was used by a trained moderator to facilitate discussion. The focus groups were digitally recorded and later transcribed verbatim. Transcripts were analyzed using a thematic analysis approach based on principles of grounded theory. Study 2 was a randomized pilot trial conducted among 23 BCa patients who were 4-weeks to 2-years post-surgery. Women were randomly assigned to one of two 12-week interventions: 1) twice-weekly DVD-based strength training (ST), or 2) weekly health education (HE) DVD viewing. The primary outcome was upper body strength as measured by a one-repetition maximum (1-RM) chest press. Measures of safety (i.e. pain and lymphedema symptoms) and quality of life (i.e. SF-36, FACT-B, and fatigue) were also taken at baseline and post-intervention. Results: For the first study, 45 BCa survivors were screened, 33 of whom participated in a focus group. The analysis resulted in two major themes: (1) factors that encourage, and (2) factors that serve as barriers to use of a DVD-based exercise program. Within these categories several sub-themes were identified, including changing notions of the relationship between physical activity and health status, pros and cons of using a DVD-based exercise program, information gaps in the healthcare setting, and time points of greater receptivity for use of a DVD-based exercise program. For the second study, 20 participants completed a post assessment. Mean adherence for study completers was 72.7% for ST and 75.0% for HE participants. A repeated measures ANCOVA, controlling for baseline measurements, time since surgery, and current treatment status, revealed a significant increase in upper body strength among ST participants (13.2 vs. 1.8 lbs., p=0.019), as well as significant improvements in shoulder flexion (right arm: 7.1 vs. -3.1°, p=0.001; left arm: 8.9 vs. -2.7°, p=0.006) and abduction (right arm: 12.5 vs. 3.5°, p=0.012; left arm: 15.8 vs. 1.5°, p<0.001). HE participants showed greater QOL improvements in general QOL (p=0.029), fatigue-related disruption (p=0.005), and role limitations due to physical (p=0.002) and emotional (p=0.002) functioning. Discussion: Study 1 findings suggest that DVD-based exercise programming is an acceptable resource for female BCa survivors. Identified themes can inform the development of future DVD-based exercise programs so that they adequately address BCa survivors' needs throughout the cancer continuum. Study 2 results demonstrate that post-operative BCa patients can safely use a DVD-based strength training program unsupervised in the home setting to improve upper body strength and range of motion. HCPs can feel confident about using proven DVD-based exercise programs to help their BCa patients regain strength and function after BCa surgery.

Keywords

breast cancer; strength training; DVD-based; quality of life; home-based; range of motion

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