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Time-Varying Effects of Estrogen Plus Progestin on Lung Cancer Death. Smoothed Time-Varying Hazard Ratios and Their 95% Confidence Intervals (Dashed Line) Comparing Estrogen Plus Progestin Users and Nonhormone Users From Study Entry. Models Are Stratified by Age Group at Randomization, Prior Lung Cancer, and Dietary Modification Trial Randomization Arm
