Access Restriction

Author Udaltsova, Natalia V.
Source CiteSeerX
Content type Text
File Format PDF
Subject Domain (in DDC) Computer science, information & general works ♦ Data processing & computer science
Subject Keyword Sa Graph ♦ Survival Analysis Using Sa Macro ♦ Proc Phreg ♦ Data Structure ♦ Survival Curve ♦ Survival Analysis ♦ Adjusted Survival Curve ♦ Multiple Time-points ♦ Proc Lifetest ♦ Kaplan Meier Curve ♦ Time Dependent Variable ♦ Multivariate Analysis ♦ Sa Graph Option ♦ Various Approach ♦ Medical Research ♦ Statistical Model ♦ Popular Method ♦ Powerful Tool ♦ Multiple Observation ♦ Baseline Statement ♦ Nested Cox Proportional Hazard Model ♦ Adequate Assumption ♦ Unique Observation ♦ Confidence Interval ♦ Preliminary Analysis
Abstract Survival analysis is a popular method in medical research. Preliminary analysis and visualization of survival curves are important to make adequate assumptions about the statistical model. This paper shows various approaches that produce Kaplan–Meier curves from PROC LIFETEST or from the baseline statement in PROC PHREG. We developed macro code to plot survival curves with confidence intervals for selected points by strata. The number of subgroups in strata and corresponding SAS graph options are calculated and assigned by design. The paper also presents macro for adjusted survival curves. Powerful tool that performs multivariate analysis is a PROC PHREG. We analyzed data with time dependent variables and repeated measurements. Two types of data structures were considered: “horizontal ” with a unique observation per ID and multiple time-points, and “vertical ” with multiple observations per ID. The paper demonstrates macros with nested Cox proportional hazard models for both types of these data structure.
Educational Role Student ♦ Teacher
Age Range above 22 year
Educational Use Research
Education Level UG and PG ♦ Career/Technical Study
Learning Resource Type Article