Distribution of potential confounding factors (%) among control men without and with vasectomy, King County, Washington, 1993–1996
| Factor . | Controls without vasectomy (n = 438) . | Controls with vasectomy (n = 265) . |
|---|---|---|
| Age at reference date (yrs) | ||
| 40–49 | 8.4 | 7.9 |
| 50–54 | 18.3 | 21.9 |
| 55–59 | 35.6 | 40.8 |
| 60–64 | 37.7 | 29.4 |
| Race | ||
| Caucasian | 96.4 | 99.2 |
| African-American | 3.6 | 0.8 |
| Family history of prostate cancer | ||
| None | 85.2 | 83.4 |
| First-degree relative | 8.4 | 12.1 |
| Second-degree relative | 6.4 | 4.5 |
| Marital status | ||
| Married | 77.6 | 87.5 |
| Single | 5.7 | 0 |
| Other | 16.7 | 12.5 |
| Annual income ($) | ||
| <30,000 | 15.7 | 8.3 |
| 30,000–49,999 | 25.6 | 21.9 |
| 50,000–74,999 | 23.3 | 33.2 |
| 75,000–99,999 | 16.7 | 17.4 |
| ≥100,000 | 17.6 | 17.7 |
| Unknown | 1.1 | 1.5 |
| Education | ||
| High school or less | 23.0 | 23.8 |
| Some college | 19.4 | 28.3 |
| College graduate | 28.8 | 24.9 |
| Graduate/professional school | 28.8 | 23.0 |
| Ever visited a urologist | 33.1 | 38.5 |
| History of BPHa | 10.3 | 15.1 |
| Current smokerb | 16.0 | 15.5 |
| Regular consumer of alcoholic beveragesc | 86.1 | 90.6 |
| Religious preference | ||
| Protestant/other | 60.3 | 65.7 |
| Catholic | 17.6 | 12.5 |
| Jewish | 2.3 | 0.8 |
| None | 19.9 | 21.1 |
| Hospitalized within the past year | ||
| No | 85.6 | 86.8 |
| Yes | 14.4 | 13.2 |
| No. of physical exams within past 5 years | ||
| 0 | 12.6 | 10.9 |
| 1–2 | 36.5 | 37.7 |
| 3–4 | 19.2 | 20.8 |
| ≥5 | 31.7 | 30.6 |
| No. of DREs within past 5 years | ||
| 0 | 14.6 | 16.6 |
| 1–2 | 41.1 | 37.0 |
| 3–4 | 25.6 | 20.7 |
| ≥5 | 23.7 | 25.7 |
| No. of PSAs within past 5 years | ||
| 0 | 66.4 | 67.9 |
| 1–2 | 20.8 | 16.2 |
| 3–4 | 7.8 | 9.4 |
| ≥5 | 5.0 | 6.4 |
| Factor . | Controls without vasectomy (n = 438) . | Controls with vasectomy (n = 265) . |
|---|---|---|
| Age at reference date (yrs) | ||
| 40–49 | 8.4 | 7.9 |
| 50–54 | 18.3 | 21.9 |
| 55–59 | 35.6 | 40.8 |
| 60–64 | 37.7 | 29.4 |
| Race | ||
| Caucasian | 96.4 | 99.2 |
| African-American | 3.6 | 0.8 |
| Family history of prostate cancer | ||
| None | 85.2 | 83.4 |
| First-degree relative | 8.4 | 12.1 |
| Second-degree relative | 6.4 | 4.5 |
| Marital status | ||
| Married | 77.6 | 87.5 |
| Single | 5.7 | 0 |
| Other | 16.7 | 12.5 |
| Annual income ($) | ||
| <30,000 | 15.7 | 8.3 |
| 30,000–49,999 | 25.6 | 21.9 |
| 50,000–74,999 | 23.3 | 33.2 |
| 75,000–99,999 | 16.7 | 17.4 |
| ≥100,000 | 17.6 | 17.7 |
| Unknown | 1.1 | 1.5 |
| Education | ||
| High school or less | 23.0 | 23.8 |
| Some college | 19.4 | 28.3 |
| College graduate | 28.8 | 24.9 |
| Graduate/professional school | 28.8 | 23.0 |
| Ever visited a urologist | 33.1 | 38.5 |
| History of BPHa | 10.3 | 15.1 |
| Current smokerb | 16.0 | 15.5 |
| Regular consumer of alcoholic beveragesc | 86.1 | 90.6 |
| Religious preference | ||
| Protestant/other | 60.3 | 65.7 |
| Catholic | 17.6 | 12.5 |
| Jewish | 2.3 | 0.8 |
| None | 19.9 | 21.1 |
| Hospitalized within the past year | ||
| No | 85.6 | 86.8 |
| Yes | 14.4 | 13.2 |
| No. of physical exams within past 5 years | ||
| 0 | 12.6 | 10.9 |
| 1–2 | 36.5 | 37.7 |
| 3–4 | 19.2 | 20.8 |
| ≥5 | 31.7 | 30.6 |
| No. of DREs within past 5 years | ||
| 0 | 14.6 | 16.6 |
| 1–2 | 41.1 | 37.0 |
| 3–4 | 25.6 | 20.7 |
| ≥5 | 23.7 | 25.7 |
| No. of PSAs within past 5 years | ||
| 0 | 66.4 | 67.9 |
| 1–2 | 20.8 | 16.2 |
| 3–4 | 7.8 | 9.4 |
| ≥5 | 5.0 | 6.4 |