Normative steps/day values for older adults: NHANES 2005-2006

Background. Pedometers are more likely than accelerometers to be used in walking interventions and other applications, including wide spread adoption by lay people. The purpose of this article is to provide older adults' sex-and-age-specific normative values for accelerometer-determined steps/day, adjusted to a pedometer-based scale. Methods. The data source was accelerometer data collected over multiple valid days (defined as ≥ 10 h/day; mean 5.8 ± SE 0.1 valid days) from 1,196 60+ year olds participating in the 2005-2006 National Health and Nutrition Examination Survey. Accelerometer data were adjusted to a pedometer scale using an established process of censoring steps counted during those minutes where activity counts totaled <500. Quintile-defined categories of adjusted steps/day (lowest, below average, average, above average, and highest) for six age groups (60-64, 65-69, 70-74, 75-79, 80-84, and 85+ years) were computed for the entire sample and separately for each sex. LMSChartmakerPro was used to create smoothed percentile curves corresponding to the 5th, 25th, 50th, 75th, and 95th percentiles. Results. Men aged 65-69 years defined the highest single category (>9,126 steps/day) and women aged 85+ years of age defined the lowest single category (<276 steps/day). In general, steps/day tended to decrease within each quintile-defined category as age increased. Similar patterns were apparent in the more detailed LMSChartmakerPro percentiles. Conclusions. These data represent the first presentation of a detailed population distribution of normative accelerometer-determined steps/day adjusted to pedometer scaling, an instrument more likely to be used in clinical and public health applications.