eAPPENDIX 1.
Baseline Characteristics of Propensity Score-Matched Veterans Aged ≤ 45 Years With Incident CRC22
| Characteristic | Urban (n = 142) | Rural (n = 142) | P value |
|---|---|---|---|
| Age at CRC diagnosis, mean (SD), y | 39.1 (4.5) | 39.1 (4.6) | |
|
| |||
| Male sex, No. (%) | 116 (81.7) | 118 (83.1) | .76 |
|
| |||
| Race, No. (%) | |||
| White | 114 (80.3) | 114 (80.3) | > .99 |
| African American | 14 (9.9) | 14 (9.9) | > .99 |
| Other | 2 (1.4) | 2 (1.4) | > .99 |
| Unknown/missing | 12 (8.5) | 12 (8.5) | > .99 |
|
| |||
| Ethnicity, No. (%) | |||
| Hispanic | 2 (1.4) | 7 (4.9) | .004 |
| Non-Hispanic | 115 (81.0) | 126 (88.7) | .004 |
| Unknown/missing | 25 (17.6) | 9 (6.3) | .004 |
|
| |||
| Body mass index, No. (%) | |||
| < 25 | 2 (1.4) | 1 (0.7) | .56 |
| 25–30 | 29 (20.4) | 25 (17.6) | .55 |
| 31–35 | 41 (28.9) | 47 (33.1) | .44 |
| 36–40 | 39 (27.5) | 40 (28.2) | .90 |
| 41–45 | 20 (14.1) | 21 (14.8) | .87 |
| > 45 | 8 (5.6) | 7 (4.9) | .79 |
| Missing | 3 (2.1) | 1 (0.7) | .31 |
|
| |||
| Comorbidities, No. (%) | |||
| Charlson Comorbidity Indexa | |||
| Acute myocardial infarction | 0 (0.0) | 0 (0.0) | > .99 |
| Congestive heart failure | 1 (0.7) | 0 (0.0) | .32 |
| Peripheral visceral diseases | 5 (3.5) | 3 (2.1) | .47 |
| Cerebrovascular diseases | 3 (2.1) | 3 (2.1) | > .99 |
| Dementia | 0 (0.0) | 0 (0.0) | > .99 |
| COPD/bronchiectasis | 25 (17.6) | 27 (19.0) | .80 |
| Rheumatoid diseases | 1 (0.7) | 3 (2.1) | .31 |
| Peptic ulcer diseases | 2 (1.4) | 3 (2.1) | .65 |
| Diabetes | 17 (12.0) | 15 (10.6) | .71 |
| Diabetes with complications | 13 (9.2) | 12 (8.5) | .83 |
| Hemiplegia | 1 (0.7) | 0 (0.0) | .32 |
| Kidney diseases | 2 (1.4) | 1 (0.7) | .56 |
| Mild liver diseases | 20 (14.1) | 14 (9.9) | .27 |
| Severe liver diseases | 3 (2.1) | 1 (0.7) | .31 |
| AIDS | 1 (0.7) | 3 (2.1) | .31 |
|
| |||
| Prior CRC Screening, No. (%) | |||
| FOBT/FITb | 25 (17.6) | 25 (17.6) | > .99 |
| Barium enemab | 1 (0.7) | 3 (2.1) | .31 |
| Colonographyb | 0 (0.0) | 0 (0.0) | > .99 |
|
| |||
| High risk factors, No. (%) | |||
| Family CRC historyc | 17 (12.0) | 20 (14.1) | .60 |
| Inflammatory bowel diseased | 13 (9.2) | 14 (9.9) | .84 |
| Gastrointestinal symptomsd,e | 95 (66.9) | 89 (62.7) | .46 |
| Systemic symptomsd,e | 46 (32.4) | 40 (28.2) | .44 |
|
| |||
| CRC characteristics, No. (%) | |||
| Proximal | 30 (21.1) | 24 (16.9) | .36 |
| Transverse colon | 10 (7.0) | 12 (8.5) | .66 |
| Distal | 64 (45.1) | 56 (39.4) | .34 |
| Metastatic at time of first diagnosisf | 16 (11.3) | 16 (11.3) | > .99 |
|
| |||
| Total mortality during follow-up period, No. (%) | 29 (20.4) | 27 (19.0) | .77 |
Abbreviations: COPD, chronic obstructive pulmonary disease; CRC, colorectal cancer; FIT, fecal immunochemical test; FOBT, fecal occult blood test.
a
Calculated using the method described by Schneeweiss et al.21
b
Anytime before the date of CRC diagnosis.
c
Anytime throughout the study period.
d
≤ 1 year before date of CRC diagnosis.
e
See eAppendix for definitions.
f
Metastases to liver, bone, lung, or central nervous system.