Assessment Of Daily Step-counts

Abstract

PURPOSE To compare the average number of steps per day measured by a pedometer and a multi-parameter monitor in free-living adult women. METHODS One pedometer and one multi-parameter monitor (measures steps, heat flux, near-body temperature, galvanic skin response and skin temperature) were distributed to 66 women, aged 37–84 years, with a mean age of 52 years. The sample was 75% white and 25% minority, with 43% having less than a 4-yr college degree, and 57% having at least a 4-yr college degree. Subjects wore the pedometer and multi-parameter monitor over a three-day period, including two weekdays and one weekend day. The average number of steps over the three day period was calculated for each device. The association between the average steps/day between the two devices was determined using a Pearson Product Correlation. Differences between the two measurements were examined using a paired sample T-test. Subjects were categorized into subgroups to determine if the association between the two devices differed by race (white vs. minority), age (<50 yrs vs. ± 50 yrs) and educational attainment (< 4-yr college degree vs. 4-yr college degree). RESULTS The average number of steps over the 3 days measured by the pedometer and the multi-parameter monitor were 8507 and 8434, respectively. The mean difference between the two methods was 73 steps (p = 0.87). There was a strong positive correlation (0.66) between the average number of steps assessed by the pedometer and the multi-parameter monitor. Similar findings were observed when the two devices were compared within the subgroups. The mean difference between the two methods was 48 steps, 37 steps, and 25 steps for the race, age and education subgroup comparisons respectively. Correlations across all sub-groups remained consistently high ranging from 0.56 to 0.85. CONCLUSIONS The data indicate that the two methods to assess steps/day, pedometer and multi-parameter monitor, yield similar results in a free-living sample of adult women. The strong association between the two methods remained across levels of education, age, and race. Supported by NHLBI (HL067052)