Hello all,
We hope you will join us this Wednesday, February 17th at the Applied
Statistics workshop when we will be happy to have Cassandra Wolos
Pattanayak (Department of Statistics). Details and an abstract are
below. A light lunch will be served. Thanks!
"Diagnostics for Covariate Balance: Propensity Score Analyses at the
Centers for Disease Control and Prevention" (Joint work with Donald B.
Rubin and the CDC)
Cassandra Wolos Pattanayak
Department of Statistics
February 17th, 2010, 12 noon
K354 CGIS Knafel (1737 Cambridge St)
ABSTRACT:
With propensity score analyses increasingly widespread, the crucial
step of scrutinizing the balance of covariates in the selected
treatment and control groups deserves emphasis. This talk focuses on
two recent collaborations with the CDC that highlight the importance
of diagnosing covariate balance at the design stage, without access to
study outcomes.
In the first application, we create matched treatment and control
groups to examine the effect of transferring one v. two embryos during
in vitro fertilization on pregnancy rates, multiple births, and other
outcomes. The matching process demonstrates the importance of
attention to detail in covariate selection and the use of balance
checking to choose a matching protocol. The second application
involves propensity score subclassification in a clinical trial
evaluating a possible prevention for perinatal sepsis in South Africa.
The clinical trial actually randomized patients to treatment or
placebo, and our analysis illustrates the possibilities for improving
covariate balance when faced with an "unlucky" randomization. Both
projects have been conducted without access to study outcomes and with
a focus on diagnostics.
Cheers,
matt.
~~~~~~~~~~~
Matthew Blackwell
PhD Candidate
Institute for Quantitative Social Science
Department of Government
Harvard University
email: mblackwell(a)iq.harvard.edu
url:
http://people.fas.harvard.edu/~blackwel/