Organizing and Analyzing the Activity Data in NHANES

Abstract

The NHANES study contains objectively measured physical activity data collected using hip-worn accelerometers from multiple cohorts. However, using the accelerometry data has proven daunting because: 1) currently, there are no agreed upon standard protocols for data storage and analysis; 2) data exhibit heterogeneous patterns of missingness due to varying degrees of adherence to weartime protocols; 3) sampling weights need to be carefully adjusted and accounted for in individual analyses; 4) there is a lack of reproducible software that transforms the data from its published format into analytic form; and 5) the high dimensional nature of accelerometry data complicates analyses. Here, we provide a framework for processing, storing, and analyzing the NHANES accelerometry data for the 2003-2004 and 2005-2006 surveys. We also provide an NHANES data package in R, to help disseminate high quality, processed activity data combined with mortality and demographic information. Thus, we provide the tools to transition from "available data online" to "easily accessible and usable data", which substantially reduces the large upfront costs of initiating studies of association between physical activity and human health outcomes using NHANES. We apply these tools in an analysis showing that accelerometry features have the potential to predict 5-year all cause mortality better than known risk factors such as age, cigarette smoking, and various comorbidities.

Obesity Trends and Associations with Types of Physical Activity and Sedentary Behavior in US Adults: National Health and Nutrition Examination Survey, 2007‐2016

“…Social desirability or recall bias may be present, especially for PA and SB, because of the self-reported data collection method of the NHANES. In future research, objective measures of PA and SB would help mitigate this bias (40). Original Article EPIDEMIOLOGY/GENETICS…”

Diurnal Physical Activity Patterns across Ages in a Large UK Based Cohort: The UK Biobank Study

“…As a result, reproducibility of our results in the UK Biobank is limited. In the interest of disseminating our work, we provide code for performing all of our analyses using the publicly accessible accelerometry data from the National Health and Nutrition Survey 2003-2006 [36] which has been organized in an analytic ready format through the R package rnhanesdata [7,37]. Our analysis is reproduced using the NHANES data via a supplementary markdown file to be uploaded to Github upon publication.…”

“…Because physical activity (PA) levels are modifiable for most adults, PA is an attractive target for interventions aimed at improving the quality of life in older adults. In addition, features of PA are known to be highly correlated with prevalence of various health conditions [ 4 ] and risk of mortality [ 5 , 6 , 7 , 8 , 9 ]. Taken together, these observations suggest the power of monitoring PA in a free-living environment to both inform the epidemiology of healthy aging and facilitate safe, independent, home living for aging individuals if incorporated into, for example, a clinical monitoring program through individuals’ primary care provider.…”

“…An alternative approach involves analyzing the entire 24 h acceleration profiles in conjunction with health outcomes. Despite evidence that specific patterns of timing and magnitudes of physical activity over the 24 h day are associated with aging [ 11 ] and mortality [ 7 , 16 ], analytic approaches that use the full acceleration profiles have been underutilized in the literature, perhaps because of the computational and methodological challenges of working with high dimensional, correlated, structured data.…”

Genome-wide association studies of 27 accelerometry-derived physical activity measurements identified novel loci and genetic mechanisms

“…Regular physical activity (PA) is associated with lower risk of a wide range of diseases, including cancer, diabetes, cardiovascular disease 1 , Alzheimer’s disease 2 , as well as mortality 3,4 . However, studies have indicated that large majority of US adults and adolescents are insufficiently active 5 , and thus PA interventions have great potential to improve public health.…”