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[2] UNIV WASHINGTON, DEPT MED, SEATTLE, WA USA
[3] UNIV WASHINGTON, DEPT EPIDEMIOL, SEATTLE, WA USA
[4] UNIV WASHINGTON, DEPT HLTH SERV, SEATTLE, WA USA
[5] UNIV PITTSBURGH, GRAD SCH PUBL HLTH, PITTSBURGH, PA USA
[6] UNIV CALIF DAVIS, DEPT INTERNAL MED, DAVIS, CA USA
[7] JOHNS HOPKINS UNIV, DEPT MED, BALTIMORE, MD USA
[8] UNIV VERMONT, DEPT PATHOL, BURLINGTON, VT 05405 USA
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