title: Repeat physical activity measurement by accelerometry among colorectal cancer patients--feasibility and minimal number of days of monitoring.
abstract: BACKGROUND
  Physical activity plays an important role in colorectal cancer and accelerometry is more frequently used to measure physical activity. The aim of this study was to evaluate feasibility of physical activity measurement by accelerometry in colorectal cancer patients under free-living conditions at 6, 12 and 24 months after surgery, to evaluate the appropriate wear time and to compare results to pedometry.
  
  
  METHODS
  Colorectal cancer patients (stage 0/I-IV) from the ColoCare study were asked to optionally wear an accelerometer and a pedometer for ten consecutive days 6, 12 and 24 months post-surgery. Participants completed a feedback questionnaire about the accelerometer measurement. The course of moderate-to-vigorous physical activity over the 10 days was investigated. Additionally, daily step counts from accelerometers and pedometers were compared.
  
  
  RESULTS
  In total, there were 317 individual time points, at which 198 participants were asked to wear an accelerometer. Fifty-nine% initially agreed to participate and of these, 83% (n = 156) completed the assessment with at least 4 days of data. Twenty-one% more consents were obtained when participants were asked on a face-to-face basis compared to recruitment by telephone (P = 0.0002). There were no significant differences in time spent in moderate-to-vigorous physical activity between different wear-time lengths of accelerometry. Both Spearman and intraclass correlation coefficients showed strong correlations (0.92-0.99 and 0.84-0.99, respectively) of moderate-to-vigorous physical activity across 3, 4, 7 and 10 days measurement. Step counts measured by accelerometry and pedometry were strongly correlated (ρ = 0.91, P < 0.0001).
  
  
  CONCLUSIONS
  This study suggest that accelerometry is a feasible method to assess physical activity in free-living colorectal cancer patients and that three valid days of physical activity measurement are sufficient for an accurate assessment.
authors.affiliation: Division of Preventive Oncology, National Center for Tumor Diseases (NCT) and German Cancer Research Center (DKFZ), Heidelberg, Germany. stephanie.tosic@nct-heidelberg.de.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Skender
authors.affiliation: Division of Preventive Oncology, National Center for Tumor Diseases (NCT) and German Cancer Research Center (DKFZ), Heidelberg, Germany. petra.schrotz-king@nct-heidelberg.de.
authors.forename: Petra
authors.initials: P
authors.lastname: Schrotz-King
authors.affiliation: Division of Preventive Oncology, National Center for Tumor Diseases (NCT) and German Cancer Research Center (DKFZ), Heidelberg, Germany. juergen.boehm@hci.utah.edu.|Huntsman Cancer Institute, Salt Lake City, UT, USA. juergen.boehm@hci.utah.edu.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Böhm
authors.affiliation: Division of Preventive Oncology, National Center for Tumor Diseases (NCT) and German Cancer Research Center (DKFZ), Heidelberg, Germany. clare.abbenhardt@nct-heidelberg.de.
authors.forename: Clare
authors.initials: C
authors.lastname: Abbenhardt
authors.affiliation: Division of Preventive Oncology, National Center for Tumor Diseases (NCT) and German Cancer Research Center (DKFZ), Heidelberg, Germany. biljana.gigic@nct-heidelberg.de.
authors.forename: Biljana
authors.initials: B
authors.lastname: Gigic
authors.affiliation: Division of Clinical Epidemiology, German Cancer Research Center (DKFZ), Heidelberg, Germany. j.chang-claude@dkfz-heidelberg.de.
authors.forename: Jenny
authors.initials: J
authors.lastname: Chang-Claude
authors.affiliation: Department of Cancer Epidemiology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA. Erin.Siegel@moffitt.org.
authors.forename: Erin M
authors.initials: EM
authors.lastname: Siegel
authors.affiliation: Division of Preventive Oncology, National Center for Tumor Diseases (NCT) and German Cancer Research Center (DKFZ), Heidelberg, Germany. k.steindorf@dkfz-heidelberg.de.
authors.forename: Karen
authors.initials: K
authors.lastname: Steindorf
authors.affiliation: Division of Preventive Oncology, National Center for Tumor Diseases (NCT) and German Cancer Research Center (DKFZ), Heidelberg, Germany. neli.ulrich@hci.utah.edu.|Cancer Prevention Program, Fred Hutchinson Cancer Research Center, Seattle, WA, USA. neli.ulrich@hci.utah.edu.|Huntsman Cancer Institute, Salt Lake City, UT, USA. neli.ulrich@hci.utah.edu.
authors.forename: Cornelia M
authors.initials: CM
authors.lastname: Ulrich
mesh_terms: D056044:Actigraphy / Q000295:instrumentation; D000203:Activities of Daily Living; D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000473:pathology / Q000503:physiopathology* / Q000628:therapy; D004867:Equipment Design; D005240:Feasibility Studies; D030141:Feedback, Psychological; D005260:Female; D005858:Germany; D006801:Humans; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D009367:Neoplasm Staging; D017060:Patient Satisfaction; D011237:Predictive Value of Tests; D011446:Prospective Studies; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires; D013997:Time Factors; D014481:United States