Description of the variables in nested case-control data set created 
from whas.dat.

Data are used in exercises in Chapter 9 of Hosmer, D.W. and Lemeshow, S. (1998)
Applied Survival Analysis: Regression Modeling of Time to Event Data,
John Wiley and Sons Inc., New York, NY 

Five controls per case were selected. 

Data are in file whasncc.dat

n = 1494

Variable	Description				Codes / Units
SET		Case-Control Set	 		1 - 249

CASE		Case-Control Status		0 = Control
							1 = Case

T		Ties Broken LENFOL		T = LENFOL if FSTAL = 0
							T = LENFOL - U(0,1)
							    if FSTAL = 1

LENFOL	Total Length of Follow-up	Days
		from Hospital Admission

FSTAT	Status as of Last			      0 = Alive
		Follow-up				1 = Dead

AGE		Age (per chart)			years

SEX		Gender				0 = Male
							1 = Female

CHF		Left Heart Failure		0 = No
		Complications 			1 = Yes

MIORD 	MI Order				0 = First
							1 = Recurrent

YRGRP		Grouped Cohort Year		1 = 1975 & 1978
							2 = 1981 & 1984
							3 = 1986 & 1988

LENSTAY	Length of Hospital Stay		Days
		Days in Hospital

NR		Number in the Risk Set in
		the original WHAS Cohort
