Table 2.

Cox Proportional Hazards Models of Overall Survival by Increasing Number of Comorbidities

	Adjusted Hazard Ratios (95% Confidence Intervals) of Overall Survival by Increasing Number of Comorbidities; p Value
Number of Comorbidities	Stage I (n = 5952)	Stages II and III (n = 5926)	Stage IV (n = 4476)
0	Reference	Reference	Reference
1	1.28 (1.17–1.41), p < 0.001	1.09 (1.01–1.18), p = 0.04	1.08 (0.99–1.17), p = 0.07
2	1.42 (1.21–1.68), p < 0.001	1.18 (1.03–1.36), p = 0.02	1.11 (0.96–1.27), p = 0.15
3+	1.63 (1.22–2.18), p < 0.001	1.40 (1.09–1.80), p = 0.008	1.05 (0.81–1.37), p = 0.72

Note: Separate analyses were performed for all stages and for individual disease stages at the time of diagnosis. Each analysis was adjusted for age, sex, race, education, smoking status, stage (for all stages and stages II and III only), and study sites.