Table 1. Descriptive characteristics of sample1 by time of blood sample before case diagnosis.
| Descriptive variable | Glioma | Controls2 |
|---|---|---|
| Total | ||
| Number | 487 | 487 |
| Percent men (mean) | 67 (63, 71)3 | 67 (63, 71) |
| Median age at blood collection | 42 (40, 43)4 | 42 (40, 43) |
| Median year of blood collection | 1986 (1976, 1989) | 1986 (1976, 1989) |
| Median age at glioma diagnosis | 57 (51, 63) | ----5 |
| Median years from blood collection to diagnosis | 15 (9, 21) | ---- |
| ≤ 5 years before diagnosis | ||
| Number | 55 | 55 |
| Percent men (mean) | 58 (45, 72) | 58 (45, 72) |
| Median age at blood collection | 42 (41, 46) | 42 (41, 47) |
| Median year of blood collection | 1988 (1984, 1989) | 1988 (1984, 1989) |
| Median age at glioma diagnosis | 45 (43, 48) | ---- |
| Median years from blood collection to diagnosis | 3 (1, 4) | ---- |
| > 10 years before diagnosis | ||
| Number | 347 | 347 |
| Percent men (mean) | 67 (62, 72) | 67 (62, 72) |
| Median age at blood collection | 42 (41, 46) | 42 (41, 46) |
| Median year of blood collection | 1985 (1975, 1989) | 1985 (1975, 1989) |
| Median age at glioma diagnosis | 59 (55, 66) | ---- |
| Median years from blood collection to diagnosis | 17 (14, 24) | ---- |
| > 15 years before diagnosis | ||
| Number | 2286 | 230 |
| Percent men (mean) | 65 (59, 71) | 65 (59, 71) |
| Median age at blood collection | 42 (40, 44) | 42 (40, 43) |
| Median year of blood collection | 1977 (1975, 1987) | 1977 (1975, 1988) |
| Median age at glioma diagnosis | 63 (59, 68) | ---- |
| Median years from blood collection to diagnosis | 21 (17, 27) | ---- |
| > 20 years before diagnosis | ||
| Number | 126 | 126 |
| Percent men (mean) | 67 (59, 76) | 67 (59, 76) |
| Median age at blood collection | 41 (38, 44) | 41 (38, 44) |
| Median year of blood collection | 1976 (1973, 1977) | 1976 (1973, 1977) |
| Median age at glioma diagnosis | 67 (63, 71) | ---- |
| Median years from blood collection to diagnosis | 26 (23, 30) | ---- |
1 Glioma study participants were blood donors (1974–2007) to the Janus Serum Bank, Oslo, Norway.
2 Control participants were individually matched to cases on age date of blood collection and sex.
3 95% confidence interval
4 Interquartile range
5 Not applicable
6 Controls are matched to cases within three months of blood collection. Therefore a matched pair may fall into separate time categories thus accounting for unequal numbers of cases and controls in this category.