1. Finnish Institute of Occupational Health; Lemminkäisenkatu 14-18 B Turku Finland 20520
2. Finnish Institute of Occupational Health; Cochrane Work Review Group; PO Box 310 Kuopio Finland 70101
3. University of Maryland Baltimore; 110 South Paca Street 4th Floor, RM 4-100 Baltimore Maryland USA 21201
4. University of Toronto; Dalla Lana School of Public Health; 155 College Street, 6th floor Toronto ON Canada M5T 3M7