Table 1.
Univariate and multivariate analysis of variables associated with overall survival in metastatic lung cancer patients, 1973–2015, Cox model. The multivariate analysis incorporated following variables: age, sex, race, marital status, histology, grade, year of diagnosis, treatment modality (of note regarding treatment, for each modality the database doses not differentiate between ‘treatment not given' and ‘unknown whether given'), and income (relating to county median income, 2010, in 10,000$). Patients with missing data for any one of these covariates were excluded from the multivariate analysis.
| Variablea | Univariate analysis | Multivariate analysis | ||||
|---|---|---|---|---|---|---|
| HR | 95% C.I. | p value | HR | 95% C.I. | p value | |
| Age | 1.013 | (1.013, 1.013) | <0.001 | 1.007 | (1.006, 1.008) | <0.001 |
| Sex (female vs. male) | 0.852 | (0.839, 0.852) | <0.001 | 0.840 | (0.825, 0.849) | <0.001 |
|
| ||||||
| Race | ||||||
| White | 1.000 (comparator group) | |||||
| Black | 0.989 | (0.978, 1.001) | 0.063 | 0.979 | (0.960, 0.999) | 0.045 |
| Am. Indian/Alaska | 1.011 | (0.952, 1.074) | NS (0.72) | 1.143 | (0.986, 1.325) | 0.076 |
| Asian/Pacific Islander | 0.753 | (0.742, 0.765) | <0.001 | 0.832 | (0.808, 0.856) | <0.001 |
| Unknown/other | 0.602 | (0.524, 0.693) | <0.001 | 0.638 | (0.475, 0.858) | 0.003 |
| Married | 0.880 | (0.873, 0.887) | <0.001 | 0.906 | (0.893, 0.919) | <0.001 |
|
| ||||||
| Histology | ||||||
| Lung carcinoma NOS | 1.000 (comparator group) | |||||
| Adenocarcinoma | 0.736 | (0.729, 0.742) | <0.001 | 0.860 | (0.844, 0.875) | <0.001 |
| Squamous cell ca. | 0.866 | (0.856, 0.875) | <0.001 | 0.910 | (0.892, 0.929) | <0.001 |
| Small cell carcinoma | 0.858 | (0.849, 0.866) | <0.001 | 1.029 | (1.008, 1.05) | 0.007 |
|
| ||||||
| Grade | ||||||
| Well diff. | 1.000 (comparator group) | |||||
| Moderately diff. | 1.173 | (1.138, 1.209) | <0.001 | 1.190 | (1.149, 1.233) | <0.001 |
| Poorly diff. | 1.512 | (1.470, 1.554) | <0.001 | 1.484 | (1.436, 1.535) | <0.001 |
| Undifferentiated | 1.781 | (1.725, 1.840) | <0.001 | 1.484 | (1.425, 1.545) | <0.001 |
|
| ||||||
| Year of diagnosis | ||||||
| 1973–9 | 1.000 (comparator group) | |||||
| 1980–9 | 0.948 | (0.928, 0.968) | <0.001 | 0.952 | (0.918, 0.987) | 0.008 |
| 1990–9 | 0.906 | (0.889, 0.924) | <0.001 | 0.935 | (0.903, 0.969) | <0.001 |
| 2000–9 | 0.773 | (0.759, 0.787) | <0.001 | 0.821 | (0.793, 0.850) | <0.001 |
| 2010–5 | 0.663 | (0.651, 0.676) | <0.001 | 0.739 | (0.712, 0.766) | <0.001 |
|
| ||||||
| Treatment | ||||||
| No treatment | 1.00 (comparator group) | |||||
| Chemotherapy only | 0.423 | (0.418, 0.428) | <0.001 | 0.488 | (0.478, 0.498) | <0.001 |
| Radiotherapy only | 0.766 | (0.759, 0.774) | <0.001 | 0.772 | (0.758, 0.787) | <0.001 |
| Chemo + radio | 0.445 | (0.440, 0.449) | <0.001 | 0.517 | (0.507, 0.527) | <0.001 |
| Incomeb | 0.977 | (0.974, 0.980) | <0.001 | 0.979 | (0.974, 0.985) | <0.001 |
HR: hazard ratio. CI: confidence interval. Am: American. NOS: non-other specified. Ca: carcinoma. Diff: differentiated. Chemo: chemotherapy. Radio: radiotherapy. aMissing values: grade: 207,149 patients. Marital status: 12,727 patients. Treatment: 10,881 patients. Age: 3 patients. Income: 73,156 patients. b2010 yearly median county income (per 10,000 dollars).