1. University of Eastern Finland; Institute of Public Health and Clinical Nutrition, Occupational Health Unit; Yliopistonranta 1 C, B/3. Krs Kuopio Finland FI-70211
2. Finnish Institute of Occupational Health; Occupational Safety and Health Review Group; PO Box 310 Kuopio Finland 70101
3. Finnish Institute of Occupational Health; Cochrane Occupational Safety and Health Review Group; Topeliuksenkatu 41a A Helsinki Finland FI-00250
4. Queen's University; School of Kinesiology and Health Studies; Kingston Ontario Canada
5. Kuopio University Hospital; BO 1777 Kuopio Finland 70211