摘要:Recently a number of papers have considered both longitudinal changes in a variable and the associated effect on the length of time to the occurrence of an event (Schork and Remington, 2003). Longitudinal research is performed to study a phenomenon as it is evolving over time. The phenomenon will generally show changes over time, but it may also show stability. Researchers in psychology often use longitudinal designs to assess change. Various statistical techniques have been used to analyze these data, including proportional hazard regression. This paper illustrates the use of the SPSS to examine blood data with this technique, as well. The advantages of using a Cox model approach to blood pressure analysis are discussed.