The NICHD Women's Contraceptive and Reproductive Experiences Study: methods and operational results.
OBJECTIVE
This paper presents methods and operational results of a population-based case-control study examining the effects of oral contraceptive use on breast cancer risk among white and black women aged 35-64 years in five U.S. locations.


METHODS
Cases were women newly diagnosed with breast cancer during July 1994 through April 1998. Controls were identified through random digit dialing (RDD) using unclustered sampling with automated elimination of nonworking numbers. Sampling was density-based, with oversampling of black women. In-person interviews were conducted from August 1994 through December 1998. Blood samples were obtained from subsets of cases and controls, and tissue samples were obtained from subsets of cases. A computerized system tracked subjects through study activities. Special attention was devoted to minimizing exposure misclassification, because any exposure-disease associations were expected to be small.


RESULTS
An estimated 82% of households were screened successfully through RDD. Interviews were completed for 4575 cases (2953 whites; 1622 blacks) and 4682 controls (3021 whites; 1661 blacks). Interview response rates for cases and controls were 76.5% and 78.6%, respectively, with lower rates for black women and older women.


CONCLUSIONS
The methodologic details of this large collaboration may assist researchers conducting similar investigations.
Marchbanks
Polly A
PA
Division of Reproductive Health, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA.
Mcdonald
Jill A
JA
Wilson
Hoyt G
HG
Burnett
Nancy M
NM
Daling
Janet R
JR
Bernstein
Leslie
L
Malone
Kathleen E
KE
Strom
Brian L
BL
Norman
Sandra A
SA
Weiss
Linda K
LK
Liff
Jonathan M
JM
Wingo
Phyllis A
PA
Burkman
Ronald T
RT
Folger
Suzanne G
SG
Berlin
Jesse A
JA
Deapen
Dennis M
DM
Ursin
Giske
G
Coates
Ralph J
RJ
Simon
Michael S
MS
Press
Michael F
MF
Spirtas
Robert
R
D000328:Adult; D044383:Black People; D001943:Breast Neoplasms / Q000139:chemically induced* / Q000453:epidemiology; D016022:Case-Control Studies; D003267:Contraception / Q000379:methods*; D003278:Contraceptives, Oral, Hormonal / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007407:Interviews as Topic; D008875:Middle Aged; D009316:National Institutes of Health (U.S.); D018456:Reproductive Medicine / Q000379:methods*; D012306:Risk; D011795:Surveys and Questionnaires; D014481:United States / Q000453:epidemiology; D044465:White People; D001741:Black or African American
D003278:Contraceptives, Oral, Hormonal