[1] Univ Texas Hlth Sci Ctr Houston, McGovern Med Sch, Internal Med, Houston, TX 77030 USA
[2] Univ Texas Hlth Sci Ctr Houston, McGovern Med Sch, Pulm & Crit Care Med, Houston, TX 77030 USA
[3] Univ Texas Hlth Sci Ctr Houston, Sch Publ Hlth, Management Policy & Community Hlth, Houston, TX 77030 USA