[1] Patient Ctr Outcomes Res Inst, Samsung Med Ctr, Seoul 06351, South Korea
[2] Sungkyunkwan Univ, Dept Clin Res Design & Evaluat, SAIHST, Seoul 06355, South Korea
[3] Sam Houston State Univ, Dept Psychol & Philosophy, Huntsville, TX 77341 USA
[4] Samsung Med Ctr, Ctr Clin Epidemiol, Seoul 06351, South Korea
[5] Sungkyunkwan Univ, Samsung Med Ctr, Sch Med, Dept Thorac & Cardiovasc Surg, Seoul 06351, South Korea
[6] Johns Hopkins Bloomberg Sch Publ Hlth, Dept Hlth Behav Soc & Epidemiol, Baltimore, MD 21205 USA