N K (2010). The relationship between ambulatory step activity, self-reported physical functioning and standardised timed walking in patients with haematological malignancies. Disability and Rehabilitation, 32(22):1819-1826. Postprint available at: http://www.zora.uzh.ch Similarly, ambulatory activity monitoring did not correlate significantly with self-reported functional status in patients with chronic obstructive pulmonary disease. [20] To the best of our knowledge, only one previous report has investigated the relationship between ambulatory step activity monitoring, self-reported physical functioning and the 6-minute standardized walking test in cancer patients.[28] There was moderate agreement between the 7-Day Physical Activity Recall and the accelerometer with longitudinal serial correlation coefficients of 0.54 (baseline), 0.24 (year 1), and 0.53 (year 2), all p-values <0.01.To summarize, the association observed between self-reported physical functioning, standardized timed walking and the outputs of ambulatory step activity varies from none to almost perfect in studies of various chronic disease populations. Only one study has investigated this issue in cancer patients, and none among HSCT patients. The aim of the current study was to determine the degree of association between self-reported physical functioning, standardized timed walking and the outputs of ambulatory step activity monitoring among outpatients with haematological malignancies recovering from HSCT.
Methods
ParticipantsThis study presents a cross-sectional analysis of baseline data collected from a subset of 117 ambulatory hematological patients after completion of HSCT at the University HospitalZurich and the Cantonal Hospital of St. Gallen, Switzerland. These baseline data were 4 collected before the patients were randomized between an ambulatory physical exercise intervention and a usual care (i.e., non-exercising) control group. Adult patients were considered eligible for the study if they had completed their HSCT treatment. Patients were excluded from the study in case of graft versus host disease (GVHD) except for grade I not requiring treatment, painful joints, instable osteolyses, chronic pain, lesions of the central or peripheral nervous system, uncontrolled cardiovascular disease, thyroid disease or diabetes.The study was approved by the local ethical committee. All patients provided written informed consent.
MeasurementsAmbulatory step activity levels were assessed with the Step Activity Monitor 3 (SAM3, Cymatech Corporation, Seattle, WA, USA). The patients were instructed to wear the SAM3 for 7 consecutive days. Activity monitoring over a 7-day period has previously been found to result in reliable and representative measures of an individual's movements on a day-to-day basis.[17] All participants were instructed to leave the SAM3 on the ankle if they had to rest or lay down during the day and to perform their daily activities as usual. The parameters assessed by the SAM3 for this study were: (1) `average steps/day`, (2) ...