Comparison of self-reported and accelerometer-assessed measurements of physical activity according to socio-demographic characteristics in Korean adults.

Open Access Volume: 40, Article ID: e2018060, 10 pages https://doi.org/10.4178/epih.e2018060 ORIGINAL ARTICLE Comparison of self-reported and accelerometerassessed measurements of physical activity according to socio-demographic characteristics in Korean adults Seung Won Lee1,2, Jee-Seon Shim2,3, Bo Mi Song1,2, Ho Jae Lee2, Hye Yoon Bae2, Ji Hye Park1,2, Hye Rin Choi1,2, Jae Won Yang1,2, Ji Eun Heo1,2, So Mi Jemma Cho1,2, Ga Bin Lee1,2, Diana Huanan Hidalgo1,2, Tae-Hoon Kim4, Kyung Soo Chung5, Hyeon Chang Kim2,3 Department of Public Health, Yonsei University of Graduate School, Seoul, Korea; 2Cardiovascular and Metabolic Diseases Etiology Research Center, Yonsei University College of Medicine, Seoul, Korea; 3Department of Preventive Medicine, Yonsei University College of Medicine, Seoul, Korea; 4Department of Cardiology, Severance Cardiovascular Hospital, Yonsei University College of Medicine, Seoul, Korea; 5Department of Internal Medicine, Institute of Chest Disease, Yonsei University College of Medicine, Seoul, Korea 1 OBJECTIVES: Previous studies have shown relatively low correlations between self-reported and accelerometer-assessed physical activity (PA). However, this association differs by socio-demographic factors, and this relationship has not been fully investigated in the general population. Thus, we investigated the correlation between self-reported and accelerometer-assessed PA and whether it differed by demographic and socioeconomic factors among the Korean general population. METHODS: This cross-sectional study included 623 participants (203 men and 420 women) aged 30 to 64 years, who completed a PA questionnaire and wore a wrist-worn accelerometer on the non-dominant wrist for 7 days. We examined the agreement for metabolic equivalent task minutes per week (MET-min/wk) between the 2 measures and calculated Spearman correlation coefficients according to demographic and socioeconomic factors. RESULTS: The kappa coefficient between tertiles of self-reported and accelerometer-assessed total MET-min/wk was 0.16 in the total population, suggesting overall poor agreement. The correlation coefficient between the 2 measurements was 0.26 (p<0.001) in the total population, and the correlation tended to decrease with increasing age (p for trend <0.001) and depression scores (p for trend <0.001). CONCLUSIONS: We found a low correlation between self-reported and accelerometer-assessed PA among healthy Korean adults, and the correlation decreased with age and depression score. When studying PA using accelerometers and/or questionnaires, age and depression need to be considered, as should differences between self-reported and accelerometer-assessed PA. KEY WORDS: Physical activity, Accelerometer, Questionnaire, Korea Correspondence: Hyeon Chang Kim Department of Preventive Medicine, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea E-mail: Received: Sep 12, 2018 / Accepted: Nov 29, 2018 / Published: Nov 29, 2018 This article is available from: http://e-epih.org/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. 2018, Korean Society of Epidemiology INTRODUCTION Physical activity (PA) is an important modifiable risk factor for cardiovascular disease (CVD), diabetes mellitus, falls, osteoporosis, obesity, some cancers, and mortality [1-4]. Epidemiologic studies usually assess PA by self-reported questionnaires for practical reasons [5]. However, self-reported data are vulnerable to reporting bias [6]. Moreover, light-intensity activities are hard to recall and tend to be under-reported [7,8]. These errors in the measurement of PA might attenuate estimates of the effect of PA on health-related outcomes [9]. Objective measures, such as pedome- www.e-epih.org | 1 Epidemiol Health 2018;40:e2018060 ters and accelerometers, have emerged as an alternative to solve these problems. Accelerometers can provide objective estimates of the duration and intensity of PA [5,10]. Agreement between questionnaire- and accelerometer-assessed PA was remarkably low in previous studies [5,11]. Recall and response bias in questionnaire surveys might be largely responsible for discrepancies between these 2 measures [12]. Previous studies reported that these biases can be influenced by demographic factors, socioeconomic status, and health status [13,14]. Furthermore, accelerometers attached to the upper body cannot detect certain activities that only use the lower body, such as weightlifting and cycling. Previous studies also reported that the association between questionnaire- and accelerometer-assessed PA differed by age, gender, ethnicity, socioeconomic status, and level of PA [5,13,14]. However, there are limited data on the association between questionnaire- and accelerometer-assessed levels of PA in the Korean population. Thus, we compared questionnaire-based and accelerometer-assessed PA among Korean adults, and investigated whether socio-demographic factors affected the correlation between these 2 measurements of PA. MATERIALS AND METHODS an version of the International Physical Activity Questionnaire (IPAQ)-Short Form, which asks for the frequency of each activity and the duration thereof during the past 7 days [16]. The short form records activities at 4 intensity levels: (1) vigorous-intensity activity such as aerobics, (2) moderate-intensity activity such as leisure cycling, (3) walking, and (4) sitting. According to the IPAQ scoring protocol [17], participants’ responses were converted to metabolic equivalent task minutes per week (MET-min/wk). Using the Ainsworth et al. [18] compendium, an average MET score was derived for each type of activity [18]. The following values were used for the analysis of IPAQ data: walking= 3.3 METs, moderate PA= 4.0 METs, vigorous PA= 8.0 METs, and total PA METmin/wk=sum of walking+moderate +vigorous MET-min/wk scores. A previous study reported Spearman rho coefficients and kappa values of test-retest reliability in Korean adults aged 15-69 years of 0.427-0.646 (median, 0.542) and 0.365-0.620 (median, 0.471), respectively [19]. The kappa values were greater than 0.4 in 5 of the 7 questionnaires. In a study of elderly individuals, the Spearman rho coefficients and kappa values of test-retest reliability for 5 parameters (vigorous days, vigorous minutes, moderate days, moderate minutes, and walk days) were 0.299-0.605 and 0.307-0.418, respectively [16]. Study population Measurement of physical activity by accelerometer This study was conducted utilizing baseline data from the Cardiovascular and Metabolic Diseases Etiology Research Center (CMERC) study, which was launched in 2013. The CMERC study consists of 2 prospective cohorts: a general population cohort (the CMERC cohort) and a co (...truncated)