Measuring and understanding adherence in a home-based exercise intervention during chemotherapy for early breast cancer
Ensuring and measuring adherence to prescribed exercise regimens are fundamental challenges in intervention studies to promote exercise in adults with cancer. This study reports exercise adherence in women who were asked to walk 150 min/week throughout chemotherapy treatment for early breast cancer. Participants were asked to wear a FitbitTM throughout their waking hours, and Fitbit steps were uploaded directly into study computers.
Descriptive statistics are reported, and both unadjusted and multivariable linear regression models were used to assess associations between participant characteristics, breast cancer diagnosis, treatment, chemotherapy toxicities, and patient-reported symptoms with average Fitbit steps/week.
Of 127 women consented to the study, 100 had analyzable Fitbit data (79%); mean age was 48 and 31% were non-white. Mean walking steps were 3956 per day. Nineteen percent were fully adherent with the target of 6686 steps/day and an additional 24% were moderately adherent. In unadjusted analysis, baseline variables associated with fewer Fitbit steps were: non-white race (p = 0.012), high school education or less (p = 0.0005), higher body mass index (p = 0.0024), and never/almost never drinking alcohol (p = 0.0048). Physical activity variables associated with greater Fitbit steps were: pre-chemotherapy history of vigorous physical activity (p = 0.0091) and higher self-reported walking minutes/week (p < 0.001), and higher outcome expectations from exercise (p = 0.014). Higher baseline anxiety (p = 0.03) and higher number of chemotherapy-related symptoms rates “severe/very severe” (p = 0.012) were associated with fewer steps. In multivariable analysis, white race was associated with 12,146 greater Fitbit steps per week (p = 0.004), as was self-reported walking minutes prior to start of chemotherapy (p < 0.0001).
Inexpensive commercial-grade activity trackers, with data uploaded directly into research computers, enable objective monitoring of home-based exercise interventions in adults diagnosed with cancer. Analysis of the association of walking steps with participant characteristics at baseline and toxicities during chemotherapy can identify reasons for low/non-adherence with prescribed exercise regimens.
KeywordsExercise Chemotherapy Breast cancer Intervention adherence
This study was supported by the Breast Cancer Research Foundation and the UNC Lineberger Comprehensive Cancer Center/University Cancer Research Fund. We thank Nora Christopher, Emily Bell, Tucker Brenizer, Will Pulley, and Nicole Markowski for recruitment, data collection, and data management. We greatly appreciate the active support from breast oncology providers and, most importantly, the willingness of breast cancer patients to participate in our study.
- 10.Mishra SI, Scherer RW, Snyder C, Geigle PM, Berlanstein DR, Topaloglu O (2012) Exercise interventions on health-related quality of life for people with cancer during active treatment. Cochrane database system review.Google Scholar
- 11.Mishra SI, Scherer RW, Geigle PM, et al. (2012) Exercise interventions on health-related quality of life for cancer survivors. Cochrane database system reviewGoogle Scholar
- 12.Furmaniak AC, Menig M, Markes MH (2016) Exercise for women receiving adjuvant therapy for breast cancer. Cochrane database system review, vol 9. p Cd005001Google Scholar
- 14.Schrack JA, Gresham G, Wanigatunga AA (2017) Understanding physical activity in cancer patients and survivors: new methodology, new challenges, and new opportunities. Cold Spring Harbor molecular case studiesGoogle Scholar
- 21.Foundation Arthritis (2010) Walk with ease: your guide to walking for better health, improved fitness and less pain (third edition). Arthritis Foundation, AtlantaGoogle Scholar
- 26.Tudor-Locke C, Bassett DR, Jr (2004) How many steps/day are enough? Preliminary pedometer indices for public health. Sports medicine (Auckland, N.Z.). 34(1):1–8Google Scholar
- 31.Centers for Disease Control and Prevention (2011) BRFSS questionnaire. Centers for Disease Control and Prevention, AtlantaGoogle Scholar
- 32.Karnofsky DA, Burchenal JH (1949) The clinical evaluation of chemotherapeutic agents in cancer. In: MacLeod CM (ed) Evaluation of chemotherapeutic agents in cancer. Columbia University Press, New York, pp 191–205Google Scholar
- 37.Kelly MJ, Dunstan FD, Lloyd K, Fone DL (2008) Evaluating cutpoints for the MHI-5 and MCS using the CGQ-12: a comparison of five different methods. BMC Psychiatry 8(10):1–9Google Scholar
- 38.Stewart AL, Kamberg CJ (1991) Physical Functioning Measures. In: Stewart AL, Ware JE Jr (eds) Measuring functioning and well-being: the medical outcomes survey. Duke University Press, Durham and LondonGoogle Scholar
- 41.Sherbourne CD (1991) Social functioning: social activity limitations measure. In: Stewart AL, Ware JE (eds) Measuring functioning and well-being: the medical outcomes study. Duke University Press, Durham and London, pp 173–181Google Scholar
- 55.Nguyen NH, Hadgraft NT, Moore MM, et al. (2017) A qualitative evaluation of breast cancer survivors’ acceptance of and preferences for consumer wearable technology activity trackers. Support Care CancerGoogle Scholar
- 59.Bade BC, Brooks MC, Nietert SB et al (2016) Assessing the correlation between physical activity and quality of life in advanced lung cancer. Integr Cancer Ther 1:1534735416684016Google Scholar