. Author manuscript; available in PMC: 2016 Mar 1.

Published in final edited form as: J Thorac Oncol. 2015 Mar;10(3):462–471. doi: 10.1097/JTO.0000000000000411

Table 4.

Analysis of Overall Survival Using Inverse Probability of Treatment Weighting with the Propensity Score

Covariate	OS (Months)
Covariate	Hazard Ratio	HR P-value	Type3 P-value
Main Effects Model ^a
Postoperative Radiation: Yes vs. No	0.89 (0.79–1.00)	0.046	0.046

Interaction Model ^b
Interaction: Postoperative Radiation with Regional Lymph Nodes Positive	-	-	0.615

Abbreviations: OS: Overall Survival; HR: Hazard Ratio

Model included postoperative radiation. Number of observations used was 1730.

Model included postoperative radiation, regional lymph nodes positive, and their interaction. Number of observations used was 1831.