Prediction of objectively measured physical activity and sedentariness among blue-collar workers using survey questionnaires

• Objectives We aimed at developing and evaluating statistical models predicting objectively measured occupational time spent sedentary or in physical activity from self-reported information available in large epidemiological studies and surveys.Methods Two-hundred-and-fourteen blue-collar workers responded to a questionnaire containing information about personal and work related variables, available in most large epidemiological studies and surveys. Workers also wore accelerometers for 1-4 days measuring time spent sedentary and in physical activity, defined as non-sedentary time.Least-squares linear regression models were developed, predicting objectively measured exposures from selected predictors in the questionnaire.Results A full prediction model based on age, gender, BMI, job group, self-reported occupational physical activity, and self-reported occupational sedentary time explained 63% (R2 adjusted) of the variance of both objectively measured occupational sedentary time and physical activity time since these two exposures were complementary. Single-predictor models based only on self-reported information about either occupational physical activity or occupational sedentary time explained21% and 38%, respectively, of the variance of the objectively measured exposures. Internal validation using bootstrapping suggested that the full and single-predictor models would show almost the same performance in new data sets as in that used for modelling.Conclusions Both full and single-predictor models based on self-reported information typically available in most large epidemiological studies and surveys were able to predict objectively measured occupational time spent sedentary or in physical activity, with explained variances ranging from 21% to 63%.

Subject headings

MEDICIN OCH HÄLSOVETENSKAP  -- Hälsovetenskap -- Arbetsmedicin och miljömedicin (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Health Sciences -- Occupational Health and Environmental Health (hsv//eng)

Keyword

accelerometry

actigraph

blue-collar worker

objective measure

physical activity

prediction

prediction model

questionnaire

sedentariness

sedentary time

Publication and Content Type

ref (subject category)

art (subject category)