[1] KUOPIO UNIV, DEPT COMMUNITY HLTH & GEN PRACTICE, KUOPIO, FINLAND
[2] UNIV TURKU, DEPT GEN PRACTICE, SF-20500 TURKU, FINLAND
[3] UNIV TAMPERE, DEPT GEN PRACTICE, SCH MED, SF-33101 TAMPERE, FINLAND
[4] FINNISH MED ASSOC, HELSINKI, FINLAND
[5] UNIV TAMPERE, TAMPERE SCH PUBL HLTH, SF-33101 TAMPERE, FINLAND