Table 1.
Pitkäranta, Republic of Karelia, Russia | North Karelia, Finland | |||||||
---|---|---|---|---|---|---|---|---|
Men | Women | Men | Women | |||||
Risk factor survey | Vitamin C sub-sample | Risk factor survey | Vitamin C sub-sample | Risk factor survey | Vitamin C sub-sample | Risk factor survey | Vitamin C sub-sample | |
1992 | ||||||||
Original sample | 500 | 157 | † | 1000 | 336 | † | ||
Cleaned sample* | 495 | 988 | ||||||
Participants | 380 | 117 | 673 | 224 | ||||
Participation rate (%) | 77 | 75 | 68 | 67 | ||||
1997 | ||||||||
Original sample | 499 | 499 | 501 | 501 | 1000 | 400 | † | |
Cleaned sample* | 486 | 486 | 500 | 500 | ||||
Participants | 309 | 244 | 440 | 338 | 712 | 191‡ | ||
Participation rate (%) | 64 | 50 | 88 | 68 | 71 | 48 | ||
2002 | ||||||||
Original sample | 500 | 500 | 500 | 500 | 1000 | 1000 | 1000 | 1000 |
Cleaned sample* | 472 | 472 | 481 | 481 | 994 | 994 | 993 | 993 |
Participants | 263 | 218 | 342 | 274 | 664 | 559§ | 762 | 642|| |
Participation rate (%) | 56 | 46 | 71 | 57 | 67 | 56 | 77 | 65 |
*Persons who had died or moved away from the study area between drawing the sample and the time of the health examination as well as persons who were in prison at the time of the study were excluded from the cleaned sample.
†Plasma vitamin C was not determined from the samples of women in 1992 in Pitkäranta and in 1992 and 1997 in North Karelia.
‡Vitamin C could not be measured in North Karelia 1997 from all samples due to technical difficulties with metaphosphoric acid used at the field laboratory.
§The plasma samples of fifty-seven men from North Karelia in 2002 were omitted because of thawing.
||The plasma samples of sixty-one women from North Karelia in 2002 were omitted because of thawing.