Table 1. Baseline Case Characteristics.
| Characteristics | Mean ± SD or Number (%) |
| No. of patients | 412 |
| Age at diagnosis (years) | 66.8±10.5 |
| Gender | |
| Male | 201 (49) |
| Female | 211 (51) |
| Race | |
| White | 288 (70) |
| Black | 94 (23) |
| Hispanic | 12 (3) |
| Other | 18 (4) |
| Insurance | |
| Private | 111 (27) |
| Medicare | 230 (56) |
| Indigenta | 58 (14) |
| Unknown | 13 (3) |
| Smoking status | |
| Current | 162 (39) |
| Former | 153 (37) |
| Never | 18 (5) |
| Unknown | 79 (19) |
| Smoking duration b | |
| <30 pack-years | 63 (24) |
| ≥30pack-years | 204 (76) |
| Reason for imaging | |
| Symptoms | 158 (38) |
| Screening | 20 (5) |
| Other indication | 132 (32) |
| Unknown | 102 (25) |
| Symptom Type c | |
| Cough/hemoptysis | 54 (36) |
| Dyspnea | 46 (29) |
| Chest pain | 24 (15) |
| Other | 34 (20) |
| Image type | |
| CXR | 223 (54) |
| CT | 156 (38) |
| Other | 10 (2) |
| Unknown | 23 (6) |
| Year of diagnosis | |
| 2000–2004 | 196 (48) |
| 2005–2009 | 216 (52) |
| Histology | |
| Squamous | 123 (30) |
| Adenocarcinoma | 213 (52) |
| Other | 76 (18) |
| Clinical Stage | |
| Stage I | 323 (78) |
| Stage II | 89 (22) |
a
Includes Medicaid, county health plan, and no insurance.
b
Of 267 cases with full smoking history data.
c
Of 158 cases presenting with symptoms.
CXR, chest x-ray; CT, computed tomography; SD, standard deviation.