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What type of plot do we generate from Cox-Snell residuals?

Consider a Cox proportional hazards model with Surv(Time, Status) ~ Age + Sex + BMI*Rx Assume we fit two versions of the model. The first uses the raw values for Age and BMI while the second uses centered values for both. Assume the average age is 50 years old and the average BMI is 25. When comparing the two models, indicate whether the numerical values of the following will be equal or not equal. Age main effect [age] BMI main effect [bmi] Sex main effect [sex] Rx main effect [rx] BMI & Rx interaction [interaction] Model predictions for a specific individual [prediction]

We usually report the rate ratio when interpreting the effect of a covariate on survival time in an AFT model. How is the rate ratio expressed in terms of model coefficients? A)

The incidence rate is most appropriate when the hazard function is constant over time. To which distribution does this correspond?

Suppose a log-rank test is performed to compare survival outcomes in 4 groups. What are the degrees of freedom of the chi-square test that is performed?

Which of the following is the regression equation for failure time in an accelerated failure time model? Equation A:

Kaplan-Meier and Nelson-Aalen are

Consider a pair of regression models based on the same covariates with Model A: Surv(Time, Status) ~ Sex + Age + Genotype + Rx Model B: Surv(Time, Status) ~ Sex + Age + Genotype*Rx Considering ONLY the main effects coefficient for each of the covariates below, which estimates will have different interpretations in the two models? Ignore any potential numerical changes in the estimates themselves and focus on the actual meaning of the coefficients. Sex: [q1] Age: [q2] Genotype: [q3] Rx: [q4]

The Wald confidence intervals for parameter estimates are based on 

How many times will the value of the Kaplan-Meier estimator change?