The median survival for current smokers was 0.76 years (95% CI, 0.67 to 0.89), and for former/never smokers was 1.01 years (95% CI, 0.89 to 1.15) [Fig 1
. The univariate HR for current smoking at diagnosis was 1.29 (95% CI, 1.12 to 1.48; p < 0.001). In addition, in univariate Cox analysis, shortened survival was associated with older age, male gender, African-American race/ethnicity, lower SES, marital status (being spouseless), illicit drug use, having adverse histologic types (SCLC or carcinoma NOS), adverse symptoms, adverse comorbidities, advanced stage and unstaged disease, and nonreceipt of treatment (Table 2
). In multivariate analysis, race/ethnicity, SES, and marital status were not independent predictors of survival. Current smoking was associated with deleterious levels of 9 of the 12 aforementioned prognostic factors, all except for adverse comorbidity, unstaged disease, and advanced age. Current smokers were significantly younger than former/never smokers, and this was the only protective association that current smokers had. Considering specific adverse comorbidities, CHF was associated with not being a current smoker (OR, 0.59; 95% CI, 0.37 to 0.93; p = 0.02), and COPD was associated with being a current smoker (OR, 1.36; 95% CI, 1.05 to 1.76; p = 0.02). In multivariate analysis, current smoking was associated with younger age (OR per 10 years, 0.72; 95% CI, 0.63 to 0.82; p < 0.001), male gender (OR for male vs female, 1.45; 95% CI, 1.11 to 1.89; p = 0.007), lower SES (OR per $10,000, 0.87; 95% CI, 0.81 to 0.94; p = 0.001), being without a spouse (OR for spouseless vs not, 1.32; 95% CI, 1.01 to 1.74; p = 0.05), having an adverse tumor histology (OR for SCLC/carcinoma NOS vs other, 1.53; 95% CI, 1.17 to 2.02; p = 0.002), having COPD (OR, 1.55; 95% CI, 1.16 to 2.08; p = 0.003), and not having CHF (OR, 0.48; 95% CI, 0.28 to 0.81; p = 0.006). These observations suggest the possibility that the observed crude hazard associated with current smoking may in large part be mediated by other important prognostic factors.