NAME:	
UMASS Aids Research Unit IMPACT Study [survival] (UISSURV.DAT)

SIZE:	
628 observations, 12 variables

SOURCE:
University of Massachusetts AIDS Research Unit (UMARU) IMPACT Study (UIS).
Provided by Drs. Jane McCusker, Carol Bigelow and Anne Stoddard.

REFERENCE:
Hosmer, D.W. and Lemeshow, S. and May, S. (2008) 
Applied Survival Analysis: Regression Modeling of Time to Event Data: 
Second Edition, John Wiley and Sons Inc., New York, NY

DESCRIPTIVE ABSTRACT:
These data are presented in Table 1.3 of the reference text.

Description of the Study
This subset of of the UIS data was used extensively in the first edition 
of this text.  UIS was a 5-year (1989-1994) 
collaborative research project (Benjamin F. Lewis, P.I., National Institute 
on Drug Abuse Grant #R18-DA06151) comprised of two concurrent randomized trials 
of residential treatment for drug abuse.  The purpose of the study was 
to compare treatment programs of different planned durations designed 
to reduce drug abuse and to prevent high-risk HIV behavior.  
The UIS sought to determine whether alternative residential treatment approaches 
are variable in effectiveness and whether efficacy depends on planned program duration.  
These data were used to illustrate model building in the first edition 
of this book and are being retained for use in the second edition primarily 
for end of chapter exercises.  The small subset of variables from the main 
study we use in this text is described below.

DISCLAIMER:  
This data is also available at the following Wiley's FTP site: 
ftp//ftp.wiley.com/public/sci_tech_med/survival

LIST OF VARIABLES:

Variable	Name		Description				Codes/Values
********************************************************************************************************************
1               id		Identification Code		        1 - 628
2               age		Age at Enrollment		        Years
3               beck            Beck Depression Score	                0.000 - 54.000
4               hercoc		Heroin/Cocaine Use During	        1 = Heroin & Cocaine
		                  3 Months Prior to Admission	        2 = Heroin Only 
						                        3 = Cocaine Only 						                        4 = Neither Heroin 
                                                                        4 = Neither 
5               ivhx		IV Drug Use History at		        1 = Never
				  Admission		                2 = Previous
						                        3 = Recent
6               ndrugtx		Number of Prior Drug 	                0 - 40
                                  Treatments
7               race		Subject's Race			        0 = White
						                        1 = Non-White
8               treat		Treatment Randomization		        0 = Short
		                  Assignment		                1 = Long
9               site		Treatment Site			        0 = A
						                        1 = B
10              los		Length of Stay in Treatment	        Days
		                  (Admission Date to Exit Date)
11              time		Time to Drug Relapse		        Days
		                  (Measured from Admission Date)
12              censor		Event for Treating Lost to	        1 = Returned to Drugs or Lost to Follow-Up
		                  Follow-Up as Returned to Drugs 	0 = Otherwise