Multinational Time Use Survey MET Score Linkage Pilot Project

University Of Oxford, Oxford

Investigators

Abstract

In the present project Risk Factor Monitoring and Methods Branch (RFMMB) would like to determine the feasibility of assigning measures of energy expenditure to the harmonized time use survey activity variables from the Multinational Time Use Survey (MTUS). Energy expenditure will be assigned as Metabolic Equivalent of Task (MET) scores. The MET score is the ratio of metabolic rate during a given task to a reference metabolic rate (3.5 ml 02-kg-1). MET scores range from ~1 for sedentary activities such as sleep or television viewing to 20+ for fast running or other highly vigorous activities. This work will be carried out with data for three countries. If it collection of data can be completed as described, a larger project could assign MET scores to some or all of the MTUS data sets from 24 diverse countries spanning four decades. This work is necessary to address in detail one key challenge of assigning MET scores to the MTUS activity codes. The activity codes include multiple activities, some of which have different levels of energy expenditure. In order to assign a valid level of energy expenditure to each activity, the project will match MET scores to underlying activities from the original country specific time use survey activities and then take a weighted average of these MET scores based on country specific estimates of time spent in different component activities. Descriptive analysis of the resulting data as well as comparison with studies of activity levels in specific domains will be used by program staff to evaluate the face and convergent validity of the study data. Furthermore, comparison with the estimated levels of energy expenditure for population sub groups with those generated by the ATUS-MET score linkage which includes more activity codes will provide insight into the validity of the proposed estimation procedure.