Wood, Robin*; Maartens, Gary*; Lombard, Carl J.†
*Department of Medicine, University of Cape Town, Cape Town; †*Centre for Epidemiological Research in South Africa, Medical Research Council, Cape Town, South Africa
Address correspondence and reprint requests to Robin Wood, Department of Medicine, Somerset Hospital, Beach Road, Green Point 8051, Cape Town, South Africa.
Manuscript received June 6, 1999; accepted October 22, 1999.