Understanding and influencing exercise behavior in hematologic cancer survivors: An examination of the intention-behavior gap

• Author / Creator

  Vallerand, James, R.

• Background: Regular exercise participation improves health and quality of life (QoL) in hematologic cancer survivors (HCS), yet many are insufficiently active. Because few who intend to exercise actually translate their intention into behavior, examining the intention-behavior gap (I-B gap) in HCS is important. Furthermore, though supervised exercise interventions produce the largest improvements in patient-reported outcomes, telephone counselling (TC) may be a cost-effective alternative which still provides important participant interaction and a wider reach. Grounding TC interventions in a theoretical understanding of the I-B gap, as described in the multi-process action control framework (M-PAC), may further improve their effectiveness. Purpose: The purpose of this dissertation was to examine the exercise I-B gap in HCS, and to develop and assess a TC intervention aimed at improving aerobic exercise behavior in HCS. Methods: This dissertation comprised two studies. Study 1 was a cross-sectional survey which assessed aerobic and strength exercise behavior, M-PAC correlates, and demographic/medical variables in 606 HCS from Alberta, Canada. Study 2 was a randomized controlled trial which assessed the feasibility and preliminary efficacy of a 12-week M-PAC-based TC exercise intervention in a sample of 51 HCS. Participants were randomized to either a weekly telephone counselling exercise (TCE) group (n=26) or a self-directed exercise (SDE) group (n=25), and completed online measures of self-reported aerobic exercise behavior, QoL, fatigue, and program satisfaction at baseline and post-intervention (12 weeks). Results: Study 1 demonstrated a substantial I-B gap for aerobic and strength exercise in HCS, resulting in the majority of HCS being insufficiently active. Specifically, only about half of those with an intention to do either regular aerobic or strength exercise, translated their intention into meeting the respective exercise guideline. As such, overall 22% of HCS were meeting the aerobic guideline only, 10% the strength guideline only, 22% both the aerobic and strength guideline combined, and 46% were meeting neither exercise guideline. M-PAC correlates were useful in explaining intention formation and translation in both aerobic and strength exercise contexts. Interestingly, HCS meeting the combined guidelines reported significantly stronger M-PAC correlates specific to both aerobic and strength exercise than those meeting either the aerobic-only or strength-only guideline. Study 2 revealed that a M-PAC based TC intervention was feasible in HCS, and produced large and meaningful improvements in aerobic exercise behavior. Specifically, adherence to the TC intervention was 93% and retention was 100%. Participants receiving TC increased their weekly aerobic exercise by 218 minutes compared to 93 minutes in the control group (p < .001, d = 2.19). Clinically meaningful mental health QoL improvements also favored the TC group (mean between-group differences > 0.33). Furthermore, the intervention yielded small-to-large between-group differences favoring the TC group in all M-PAC correlates (d = 0.20 to 1.11), and changes in coping planning, perceived opportunity, exercise identity, and habit partially mediated changes in aerobic exercise behavior. Conclusions: Few HCS are meeting the combined or individual exercise guidelines perhaps because substantial I-B gaps exist for both aerobic and strength exercise. The M-PAC-based TC intervention strengthened motivational, regulatory, and reflexive processes, which corresponded with increased aerobic exercise behavior and meaningful mental health improvements in HCS. Still, the absence of changes in physical health and fatigue is a common trend amongst remote exercise interventions and requires further investigation. Future phase III trials of M-PAC-based TC should look to demonstrate improvements in exercise behavior and patient-reported outcomes in HCS, other cancer survivor groups, and versus TPB-based TC.

• Subjects / Keywords

  • Exercise, Hematologic cancer survivors, intention-behavior gap

• Graduation date

  Spring 2018

• Type of Item

  Thesis

• Degree

  Doctor of Philosophy

• DOI

  https://doi.org/10.7939/R36T0HB53

• License

  Permission is hereby granted to the University of Alberta Libraries to reproduce single copies of this thesis and to lend or sell such copies for private, scholarly or scientific research purposes only. Where the thesis is converted to, or otherwise made available in digital form, the University of Alberta will advise potential users of the thesis of these terms. The author reserves all other publication and other rights in association with the copyright in the thesis and, except as herein before provided, neither the thesis nor any substantial portion thereof may be printed or otherwise reproduced in any material form whatsoever without the author's prior written permission.