[1] Univ Alabama Birmingham, Epidemiol, Birmingham, AL USA
[2] Univ Alabama Birmingham, Biostat, Birmingham, AL USA
[3] Michigan State Univ, Epidemiol, E Lansing, MI 48824 USA
[4] Univ Alabama Birmingham, Med, Birmingham, AL USA
[5] Univ Cincinnati, Neurol, Cincinnati, OH USA
[6] Univ Alabama Birmingham, Hlth Care Org & Policy, Birmingham, AL USA