Table 1.
Baseline characteristics and follow-up data of study participants
| Characteristics | Population-matched cohort | Sibling cohort | ||
|---|---|---|---|---|
| Exposed individuals (N = 167,836) | Matched unaffected individuals (N = 1,631,801) | Exposed individuals (N = 101,493) | Unaffected full siblings (N = 179,209) | |
| Age at index date, mean ± SD, years | 36.57 ± 14.16 | 36.21 ± 13.96 | 36.68 ± 13.67 | 37.62 ± 14.80 |
| Follow-up time (for cancer incidence), median (IQR), years | 7.13 (3.09–11.92) | 7.27 (3.16–12.21) | 7.34 (3.21–12.12) | 7.82 (3.49–13.10) |
| Follow-up time (for cancer mortality), median (IQR), years | 7.28 (3.17–12.11) | 7.45 (3.24–12.44) | 7.51 (3.30-12.31) | 7.97 (3.61–13.39) |
| Sex, N (%) | ||||
| Male | 63,920 (38.08) | 624,287 (38.26) | 38,735 (38.17) | 92,107 (51.40) |
| Female | 103,916 (61.92) | 1,007,514 (61.74) | 62,758 (61.83) | 87,102 (48.60) |
| Educational level, years, N (%) | ||||
| < 9 | 6133 (3.65) | 51,173 (3.14) | 3517 (3.47) | 10,083 (5.63) |
| 9–12 | 111,806 (66.62) | 971,908 (59.56) | 68,945 (67.93) | 116,585 (65.06) |
| > 12 | 39,148 (23.33) | 505,262 (30.96) | 25,865 (25.48) | 45,756 (25.53) |
| Unknown | 10,749 (6.40) | 103,458 (6.34) | 3166 (3.12) | 6785 (3.78) |
| Marital status, N (%) | ||||
| Single | 91,174 (54.32) | 883,724 (54.16) | 54,999 (54.19) | 87,762 (48.97) |
| Married or cohabiting | 40,538 (24.15) | 559,519 (34.29) | 25,496 (25.12) | 63,594 (35.49) |
| Divorced or widowed | 30,957 (18.44) | 137,084 (8.40) | 18,433 (18.16) | 19,167 (10.70) |
| Unknown | 5167 (3.09) | 51,474 (3.15) | 2565 (2.53) | 8686 (4.84) |
| Yearly family income level, N (%) | ||||
| Lowest 20% | 55,764 (33.23) | 297,714 (18.24) | 26,750 (26.36) | 29,668 (16.55) |
| Middle | 85,393 (50.88) | 949,489 (58.19) | 56,504 (55.67) | 109,195 (60.93) |
| Top 20% | 18,174 (10.83) | 297,883 (18.25) | 15,804 (15.57) | 34,928 (19.49) |
| Unknown | 8505 (5.06) | 86,715 (5.32) | 2435 (2.40) | 5418 (3.03) |
| Charlson Comorbidity Index, N (%) | ||||
| 0 | 133,457 (79.52) | 1,417,180 (86.85) | 81,682 (80.48) | 150,913 (84.21) |
| 1 | 26,462 (15.77) | 174,958 (10.72) | 15,235 (15.01) | 22,533 (12.57) |
| ≥ 2 | 7917 (4.72) | 39,663 (2.43) | 4576 (4.51) | 5763 (3.22) |
| Family history of cancer, N (%) | ||||
| Yes | 42,291 (25.20) | 430,549 (26.38) | 27,798 (27.39) | 52,258 (29.16) |
| No | 125,545 (74.80) | 1,201,252 (73.62) | 73,695 (72.61) | 126,951 (70.84) |
| History of substance use disordersa, N (%) | ||||
| Yes | 19,653 (11.71) | 40,929 (2.51) | 10,923 (10.76) | 7701 (4.30) |
| No | 148,183 (88.29) | 1,590,872 (97.49) | 90,570 (89.24) | 171,508 (95.70) |
| Comorbid substance use disordersb, N (%) | ||||
| Yes | 10,758 (6.41) | - | 6289 (6.20) | - |
| No | 157,078 (93.59) | - | 95,204 (93.80) | - |
| Type of stress-related disorders, N (%) | ||||
| PTSD | 12,613 (7.52) | - | 7195 (7.09) | - |
| Acute stress reaction | 72,970 (43.48) | - | 44,044 (43.40) | - |
| Adjustment disorder and other stress reactions | 76,738 (45.72) | - | 46,956 (46.27) | - |
| New onset morbidity during follow-up (for cancer incidence) | ||||
| Smoking-related morbidityc, N (%) | ||||
| Yes | 9328 (5.56) | 46,079 (2.82) | 5583 (5.50) | 8012 (4.47) |
| No | 158,508 (94.44) | 1,585,722 (97.18) | 95,910 (94.50) | 171,197 (95.53) |
| Alcohol-related morbidityd, N (%) | ||||
| Yes | 16,166 (9.63) | 26,053 (1.60) | 9598 (9.46) | 4984 (2.78) |
| No | 151,670 (90.37) | 1,605,748 (98.40) | 91,895 (90.54) | 174,225 (97.22) |
| New onset morbidity during follow-up (for cancer mortality) | ||||
| Smoking-related morbidityc, N (%) | ||||
| Yes | 9898 (5.90) | 49,747 (3.05) | 5907 (5.82) | 8629 (4.82) |
| No | 157,938 (94.10) | 1,582,054 (96.95) | 95,586 (94.18) | 170,580 (95.18) |
| Alcohol-related morbidityd, N (%) | ||||
| Yes | 16,284 (9.70) | 26,544 (1.63) | 9666 (9.52) | 5075 (2.83) |
| No | 151,552 (90.30) | 1,605,257 (98.37) | 91,827 (90.48) | 174,134 (97.17) |
Abbreviations: N, number; SD, standard deviation; IQR, interquartile range
a First diagnosis of a substance use disorder, occurred > 3 months before index date
b New onset substance use disorders that was diagnosed between 3 months before and 1 year after index date
c Including COPD and coronary heart diseases
d Including alcohol abuse and alcoholic liver cirrhosis