Hi all,
In follow-up to the thought-provoking discussion we had in the workshop
today, Victoria kindly agreed to share her slides. They contain useful
guidelines for dealing with missing data.
Best,
Konstantin
On Mon, Oct 3, 2011 at 2:05 AM, Konstantin Kashin
<kkashin(a)fas.harvard.edu>wrote;wrote:
Dear all,
Please join us for the Applied Statistics Workshop (Gov 3009) this
Wednesday, October 5 from 12.00 - 1.30 pm in CGIS Knafel Room 354. Victoria
Liublinska, a Ph.D. candidate from the Statistics Department at Harvard
University, will present a paper entitled "Addressing missing data issues in
a study with rare binary outcomes constrained by a small sample size". As
always, a light lunch will be provided.
The abstract for the presentation is:
*We (re)analyze the data obtained in a recent study conducted to evaluate
safety and efficacy of a new device designed for vertebroplasty. The
following are just a few issues that had to be addressed: missing data in
some covariates, incorrect analysis applied initially to the primary
endpoint, missing data in secondary endpoints. The latter involved
additional challenges such as panel data (responses were collected twice
over time with a non monotone missingness pattern), secondary endpoints were
rare binary events. The analysis was complicated by a relatively small
sample size. Our work demonstrates how a complex missing data issue can be
broken down into a set of small tasks that are solved individually. Some
tasks involved multivariate missing data imputation using chained equations
(van Buuren and Oudshoorn 2000; Raghunathan et al. 2001) with carefully
chosen conditional models. Other tasks called for new state-of-the-art
solutions, such as z-transformation procedure for combining repeated
p-values (D. Rubin et al. 2011 (to be submitted), C. Licht 2009 Ph.D.
thesis) or enhanced tipping-point graphs that assess sensitivity to various
deviations from assumptions made about the missing data mechanism (Yan et
al. 2009, Campbell et al. 2011).*
This is joint work with D. Rubin and R. Gutman.
An up-to-date schedule for the workshop is available at
http://www.iq.harvard.edu/events/node/1208.
Best,
Konstantin
--
Konstantin Kashin
Ph.D. Student in Government
Harvard University
Mobile: 978-844-0538
E-mail: kkashin(a)fas.harvard.edu
Site:
http://people.fas.harvard.edu/~kkashin/
--
Konstantin Kashin
Ph.D. Student in Government
Harvard University
Mobile: 978-844-0538
E-mail: kkashin(a)fas.harvard.edu
Site:
http://people.fas.harvard.edu/~kkashin/