Assistance with inverse probability of censoring weights - numerator

mecramarathon — Thu, 05 Jun 2025 02:25:28 GMT

Hello all,

I am working with a dataset in long format, where each row represents a specific month for a patient (e.g., row 1 = month 1, row 2 = month 2, etc.). Patients become censored (censor=0 -> censor=1) at the month they deviate from their assigned treatment strategy (or by month=12 if they do not start their assigned treatment).

I am performing an inverse probability of censoring weighting (IPCW) analysis to estimate the probability of remaining uncensored. For the denominator model, I have included the variables month, baseline covariates (cov1, cov2) and time-varying covariates (cov3, cov4).

However, I am unsure about the appropriate specification for the numerator model. Should it include only baseline covariates (cov1, cov2) (option 1) or should it just be the month variable (option 2)?

numerator - option 1

proc genmod data=example descending;

class id month (ref='12');
model censor = month / dist=binomial link=logit;

repeated subject = id;

output out=censor_num p=num;

run;

numerator - option 2

proc genmod data=example descending;

class id cov1 cov2;
model censor = cov1 cov2 / dist=binomial link=logit;

repeated subject = id;

output out=censor_num p=num;

run;

denominator

proc genmod data=example descending;

by exposure_final;

class id month (ref='12') cov1 cov2;
model censor = month cov1 cov2 / dist=binomial link=logit;
repeated subject = id;

output out=censor_den p=den;

run;

topic Assistance with inverse probability of censoring weights - numerator in Statistical Procedures

Assistance with inverse probability of censoring weights - numerator