%0 Journal Article
%@ 1438-8871
%I Gunther Eysenbach
%V 14
%N 1
%P e29
%T Active-Q: Validation of the Web-Based Physical Activity Questionnaire Using Doubly Labeled Water
%A Bonn,Stephanie Erika
%A Trolle Lagerros,Ylva
%A Christensen,Sara Elisabeth
%A Möller,Elisabeth
%A Wright,Antony
%A Sjölander,Arvid
%A Bälter,Katarina
%+ Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Nobels väg 12a, Stockholm, SE-171 77, Sweden, 46 8 524 822 98, stephanie.bonn@ki.se
%K activity assessment
%K epidemiology
%K Internet
%K total energy expenditure
%D 2012
%7 15.02.2012
%9 Original Paper
%J J Med Internet Res
%G English
%X Background: Increased use of the Internet provides new opportunities for collecting data in large studies. The aim of our new Web-based questionnaire, Active-Q, is to assess total physical activity and inactivity in adults. Active-Q assesses habitual activity during the past year via questions in four different domains: (1) daily occupation, (2) transportation to and from daily occupation, (3) leisure time activities, and (4) sporting activities. Objective: The objective of our study is to validate Active-Q’s energy expenditure estimates using the doubly labeled water (DLW) method, and to assess the reproducibility of Active-Q by comparing the results of the questionnaire completed by the same group on two occasions. Methods: The validity and reproducibility of Active-Q were assessed in a group of 37 individuals, aged 20 to 65 years. Active-Q was distributed via email to the participants. The total energy expenditure of the participants was assessed using DLW for 11 consecutive days. Results: The median time to complete Active-Q was 6.1 minutes. The majority of participants (27/37, 73%) reported that the questionnaire was “easy” or “very easy” to answer. On average, Active-Q overestimated the total daily energy expenditure by 440 kJ compared with the DLW. The Spearman correlation between the two methods was r = 0.52 (P < .001). The intraclass correlation coefficient for total energy expenditure between the results of Active-Q completed on two occasions was 0.83 (95% CI 0.73-0.93). Conclusions: Active-Q is a valid and reproducible method of assessing total energy expenditure. It is also a user-friendly method and suitable for Web-based data collection in large epidemiological studies. 
%M 22356755
%R 10.2196/jmir.1974
%U http://www.jmir.org/2012/1/e29/
%U https://doi.org/10.2196/jmir.1974
%U http://www.ncbi.nlm.nih.gov/pubmed/22356755